美国环保局 EPA 试验 方法 3541

美国EPA关于大气自动监测系统性能指标的规定和测试方法引言环境空气污染的自动监测方法有多种，一般采用湿法和干法两种。

湿法是基于化学量理论的库仑法和电导法等测量原理，需使用大量试剂，存在试剂调整和废液处理等问题，操作比较繁琐，故障率较高，维护工作量较大；干法是基于物理光谱测量理论，使样品始终保持在气体状态，没有试剂的损耗，维护工作量较小。

比如SO2测量采用紫外荧光法，NOx测量采用化学发光法，O3测量采用紫外光度法，CO测量采用气体过滤相关分析法等，目前我国绝大部分空气自动监测采用的是该方法。

干法测量以欧美为主。

美国开展空气自动监测已有30年的历史，在空气自动监测方面积累了丰富的经验，并制定了详细的规范。

其中物理光谱法作为美国EPA的推荐方法,得到了广泛的应用。

湿法测量以日本为主,但自1996年起日本在法定的测量方法中增加了干式测量法。

利用物质的光谱特性进行污染物的分析已成为自动监测仪器发展的必然趋势。

我国在环境空气质量监测和质量保证方面的规定都参考了美国国家环保署（EPA）的规定。

目前，大气自动监测和空气质量日报工作在我国大部分省市已广泛开展，自动监测仪器监测数据的准确可靠是日报工作中的基础。

为使监测人员了解美国EPA关于空气自动监测的相关规定，特将其有关SO2、NO2、O3、CO自动监测仪器的性能指标规定和测试方法作简要说明，以供参考。

一、美国EPA对性能指标及判定原则的规定1、性能指标B-1自动监测仪器性能指标M/0.02447,M是该气体的摩尔质量。

2、判定原则对于每个性能指标（量程除外），测试程序从开始起要重复7次，得到7组测试结果。

每组结果要和表B-1中的规定指标相比较，高于或超出规定指标的值是一个超标值。

每个参数的7个结果说明如下：（1）0次超标：被测的参数合格；（2）3次或更多次超标：该参数不合格；（3）1次或2次超标：再重复测试该参数 8次，得到共15个测试结果。

将此15个测试结果说明如下：a：1次或2次超标：通过测试；b：3次以上：该参数不合格。

epa测试标准
EPA（美国环保局）的测试标准是针对各种污染物和产品制定的，旨在确保产品符合相关法规和标准，以保护环境和人类健康。

以下是一些EPA的测试标准：
污染物排放限制：EPA制定了一系列污染物排放限制，要求企业、工厂和机构遵守。

这些限制涵盖了空气、水和土壤中的污染物，如二氧化硫、氮氧化物、挥发性有机化合物等。

消费品安全标准：EPA负责制定和执行消费品安全标准，以确保消费品不会对人类健康造成危害。

这些标准涵盖了家电、家具、儿童用品、玩具、化妆品等产品。

农药注册与评价：EPA负责评价农药的安全性和有效性，以确保农药的使用不会对人类健康和环境造成危害。

化学物质管理：EPA负责管理和限制化学物质的生产和使用，以确保这些物质不会对环境和人类健康造成危害。

环保设备与系统性能测试：EPA还制定了各种环保设备与系统性能测试标准，以确保这些设备能够有效地降低污染物的排放。

以上是一些EPA的测试标准，具体标准可能因产品、污染物和法规而有所不同。

在进行相关测试时，建议咨询专业的环保机构或实验室，以确保测试结果的准确性和可靠性。

方法3540C索氏萃取如有问题请mail至:piery2006@1.0范围及应用1.1方法3540是从土壤、淤泥和废弃物等固体中萃取不挥发性或半挥发性的有机化合物程序.索氏萃取过程确保样品基体同萃取溶剂能紧密地结合.1.2本方法适用于能溶于水和微溶于水的有机物质分离和浓缩,是多种色谱程序前置处理方法.1.3本方法仅限于受过训练的分析者,或在有受过训练的分析者的监控下进行,每个分析者必须展示其利用此方法获得可接受的结果的能力.2.0方法概述2.1将固体样品同无水硫酸钠混合,放置于抽取套管中或玻璃纤维的两栓之间,在索氏提取器内利用合适的溶剂萃取.2.2萃取物然后经干燥、浓缩(如有必要)，并根据需要,被交换进入一种能和所使用的提纯或测试步骤相容的溶剂中.3.0干扰参考方法3500.4.0仪器及材料4.1索氏提取器-内径为40mm,有500mL的圆底烧瓶.4.2干燥柱-内径为20mm的派莱克斯色谱柱,底部有派莱克斯玻璃纤维.备注:在严重污染的萃取物经过后,多孔的玻璃圆盘很难去除污染.可以购买到无孔的柱.使用一小垫的玻璃纤维来放置吸收剂.在将色谱柱装上吸收剂之前,先用50mL丙酮接着用50mL的洗脱溶剂清洗玻璃纤维垫.4.3 K-D浓缩装置4.3.1浓缩管-10mL,有刻度(Kontes K-570050-1025型或同级品).有圆形玻璃塞,防止萃取物的挥发.4.3.2蒸馏烧瓶-500mL(Kontes K-570001-500型或同级品).用弹簧,夹子或其物体将它与浓缩管连接。

4.3.3斯奈德柱-三大球式(Kontes K-503000-0121型或同级品).4.3.4斯奈德柱-两小球型(Kontes K-569001-0219型或同级品).4.3.5弹簧-1/2英寸(Kontes K-662750型或同级品).备注:以下玻璃器皿推荐在需要使用K-D蒸发浓缩器的浓缩程序中使用,用来回收溶剂.各州或当地政府管理挥发性有机物气体排放的法令中可能需要包括这些仪器.环境保护署推荐采用此类型的回收系统来执行排放减量项目.溶剂回收是遵守废弃物减量和防止污染的一项措施.4.4溶剂蒸汽回收系统-(Kontes K-545000-1006或K-547300-0000型,A级玻璃6614-30或同级品).4.5沸腾片-溶剂萃取时用,约10/40筛网(材质为碳化硅或同级品).4.8恒温水槽-加热用,有同心环盖,能够控制温度(±5℃),水槽应该在通风橱内使用.4.7小瓶-容量为2mL,具有聚四氟乙烯(PTFE)线型螺纹盖或小瓶顶端为卷曲的.4.8玻璃或纸质套管或玻璃纤维-没有被污染.4.9加热套-流变式控制.4.10一次性玻璃的巴氏吸管和烧瓶.4.11测试干重百分率的仪器.4.11.1干燥炉-能够维持温度105℃.4.11.2干燥器.4.11.3坩锅-瓷坩锅或一次性的铝坩锅.4.12研磨设备. 4.13分析天平-能够精确至0.0001g.5.0试剂5.1所有测试用到的无机化学药品均为试剂等级.除非有特别说明,所有的无机试剂必须符合美国化学协会分析试剂委员会的说明书.如果其它等级的化学试剂探明的纯度足够高,使用时不会降低测试的准确度,则也可以使用.5.2不含有机物的试剂水.本方法中提到的水都是不含有机物的试剂水,见本手册第一章的定义.5.3硫酸钠(颗粒状,无水)Na 2SO 4.放在浅盘中在400℃下加热4小时提纯,或是用二氯甲烷预先清洗硫酸钠.如果预先用二氯甲烷清洗硫酸钠,必须分析一个方法空白溶液,证明硫酸钠中不存在干扰.5.4萃取溶剂-所有的溶剂都是农药等级或是同等级的试剂.5.4.1泥土/沉积物和含水的淤泥样品应使用下列溶剂组合中任何一种萃取.5.4.1.1丙酮/已烷(1:1的体积比),CH 3COCH 3/C 6H 14.备注:这种溶剂组便具有较低的处理成本和较低的毒性.5.4.1.2二氯甲烷/丙酮(1:1的体积比),CH 2Cl 2/ CH 3COCH 3.5.4.2其它的样品应使用以下的溶剂萃取:5.4.2.1二氯甲烷, CH 2Cl 2.5.4.2.2甲苯/甲醇(10:1的体积比),C 6H 5CH 3/CH 3OH.5.5交换溶剂-所有的溶剂都是农药等级或是同级品.5.5.1已烷, C 6H 14.5.5.2 2-丙醇,(CH 3)2CHOH.5.5.3环已酮,C 6H 12.5.5.4氰甲烷,CH 3CN.6.0样品的收集,储存和处理见《有机分析物》第4.1节的介绍说明.7.0程序7.1样品的处理7.1.1沉积物/泥土样品-倒去沉积物样品上的水层,将样品充分混合均匀,特别是复杂样品.将一些异物如树枝,树叶和石头去除.7.1.2废弃物样品-在萃取之前,由多相组成的样品必须由第二章的相分离方法进行制备.本萃取程序仅适用于固体.7.1.3将废弃物样品干燥有助于研磨-研磨或者将废弃物再细分,让它能通过1mm的筛网或是能从1mm的小孔挤出.向研磨机中加入足够多的样品,在研磨后能产生至少10g样品.7.1.4胶质,纤维状或油状的材料不适用于研磨的样品应将它切碎,撕碎,或是其它的将样品颗粒最小化,便于混合和使样品的表面最大利于萃取.将样品中加入无水硫酸钠(1:1)有利于样品的研磨.7.2测试干重的百分率-当样品以干重为基础计算结果时,在称量一份用作分析测试样品的同时应称量一份样品用于计算干重的百分率.警告:干燥炉应放在橱中或通风条件下进行.当干燥严重受污染的样品时,可能会对实验室产生严重的污染.在称量要萃取的样品之后,接着称5-10g样品放入空的坩锅中.将此份试样在105℃烘烤过夜.在称量之前,使试样在干燥器中冷却.计算干重百分率的公式如下:干重%=干重(g)/样品重(g)×100这种干燥炉中的样品不适用于萃取.一旦干重测量好后,应适当地处理掉.7.3将10g固体样品与10g无水硫酸钠混合好之后,放入抽取套管中.在萃取期间,抽取套管能够自由地排放溶剂.另外,在索氏抽取器中,样品的上方下方各放一块玻璃纤维栓来代替套管也是可以接受的.7.3.1向样品上加1.0mL代用标准掺料溶液(代用标准物质及基体掺料溶液详见方法3500).7.3.2向每个分析批次选择作为掺料的样品中加入1.0mL基体掺料标准溶液.7.3.3选择合适的基体掺料化合物及其浓度请参照《方法3500》的5.5和8.3节.7.4将大约300mL的萃取溶剂(5.4节)加入到一个500mL的圆底烧瓶中, 烧瓶中放有一两块的沸腾片.将烧瓶装到提取器上, 萃取样品16-24小时,每小时萃取4-6个循环.7.5萃取完成后,让萃取物冷却.7.6组装好一个K-D浓缩器(节4.3),如有必要,将1个10mL的浓缩管接到500mL 的蒸馏烧瓶上.7.7遵照仪器生产商的指导,将溶剂蒸汽回收玻璃器皿(浓缩和收集装置)( 4.4节)与K-D仪器的斯奈德柱连接.7.8将萃取物通过含有大约10mm无水硫酸钠的干燥柱,将收集到的干燥后的萃取物加入至K-D浓缩器中,使用100到125mL的萃取溶剂清洗萃取烧瓶及硫酸钠柱,以完成量的转移.7.9向烧瓶加入一两块干净的沸腾片，接上一个三球的斯奈德柱.往斯奈德柱的顶端加大约1mL二氯甲烷预先使柱湿润,将K-D装置放入热的恒温水槽中(温度高于溶剂的沸点15-20℃),浓缩管部分地浸入热水中,烧瓶的整个圆形底部则完全浸入在热的蒸汽中.按照需要,调节仪器在竖直方向上的位置和水的温度,在10-20分钟内完成浓缩.在适当的蒸馏速度下,斯奈德柱的球形部分会快速振动作响,但是腔内却没有大量的液体流动.当液体的体积明显达到1-2mL时,将K-D装置从水浴中取出来,让液体冷却回流至少10分钟.7.10如果需要交换溶剂 (如表1),则快速移开斯奈德柱,加入大约50mL交换溶剂和一块新的沸腾片,重新接上斯奈德柱.依7.9所述,将萃取物浓缩,如果有必要,需提高水浴的温度来维持合适的蒸馏,当液体的体积再次达到1-2mL时,将K-D装置从水浴中取出,让液体冷却回流至少10分钟.7.11移开斯奈德柱,用1-2mL的二氯甲烷或交换溶剂冲洗烧瓶及其底部与浓缩器的接口,洗液冲入浓缩管中.如果有硫的晶体析出造成困扰,继续使用方法3660净化.萃取的物质可进一步使用第7.12节所述的技术浓缩或使用最后一次使用的溶剂调节体积至10.0mL.7.12如果依照表1需进一步浓缩,使用微斯奈德柱技术(节7.12.1)或氮气排放技术(节7.12.2)调节萃取物至最终需要的体积.7.12.1微斯奈德柱技术7.12.1.1加入一至两块干净的沸腾片至浓缩管中,然后接上一个两球的微斯奈德柱.往柱的顶部加入大约0.5mL二氯甲烷预先使斯奈德柱湿润.将K-D装置放入热的水浴槽中,使浓缩管部分地浸入热水中. 根据需要,调节仪器在竖直方向上的位置和水的温度,在5-10分钟内完成浓缩. 在适当的蒸馏速度下,斯奈德柱的球形部分会快速振动作响,但是腔内却无大量的液体流动。

epa评估方法EPA评估方法EPA（美国环境保护署）评估方法是一种用于评估环境影响和风险的科学方法。

它在环境保护领域得到广泛应用，用于评估化学品、污染物、废物和其他环境因素对人类健康和生态系统的潜在影响。

本文将介绍EPA评估方法的基本原理和应用。

一、EPA评估方法的基本原理EPA评估方法基于科学研究和风险评估的原则，通过收集、整理和分析大量的环境和健康数据，评估特定环境因素对人类和生态系统的潜在影响。

其基本原理包括以下几个方面：1. 数据收集和整理：EPA评估方法首先需要收集相关的环境数据和健康数据，包括化学物质的物理化学性质、毒性数据、环境浓度和暴露途径等。

同时，还需要收集人类健康效应和生态效应的相关数据。

2. 风险评估模型：EPA评估方法使用风险评估模型来分析环境因素对人类和生态系统的潜在影响。

这些模型基于流行病学、毒理学和环境科学等学科的知识，通过定量分析和预测来评估风险水平。

3. 不确定性分析：EPA评估方法还包括不确定性分析，用于评估评估结果的可靠性和确定性。

不确定性分析可以通过敏感性分析、模拟和统计方法等来进行。

二、EPA评估方法的应用EPA评估方法广泛应用于环境监测、风险评估和决策支持等领域。

其主要应用包括以下几个方面：1. 环境污染评估：EPA评估方法可以用于评估污染物对环境的潜在影响。

通过收集环境数据和污染物的毒性数据，结合风险评估模型，可以评估污染物的暴露水平和潜在风险。

2. 化学品评估：EPA评估方法可以用于评估化学品对人类健康和环境的潜在影响。

通过收集化学品的物理化学性质、毒性数据和暴露途径等信息，结合风险评估模型，可以评估化学品的致癌、致畸和致突变等潜在风险。

3. 废物管理评估：EPA评估方法可以用于评估废物对环境和人类健康的潜在影响。

通过收集废物的组成、毒性数据和处理方式等信息，结合风险评估模型，可以评估废物的处理风险和环境影响。

4. 环境政策制定：EPA评估方法可以用于支持环境政策的制定和实施。

方法3540（3）1.0应用范围1.13540是•个从土壤，淤泥以及废弃物中萃取挥发性和半挥发性物质的过程，索氏萃取过程保证了样品与萃取试剂充分接触1.2这个方法应用在-些溶于水或微溶于水的有机物质分离和浓缩过程中.13这种方法使用所得结果可靠性的能力，必须要经过论证.2.0方法概述2」固体样品与无水硫酸钠混合后放置在萃取管或是玻璃纤维的两个塞/之间，并且加入适当的溶剂进行萃取.2.2萃取是•个利用匹配溶剂对测试成分进行•提取然后的过程,必要时要进行•浓缩.3.0干扰参考方法35004.0设备及材料4」索氏萃取装置：直径40毫米,体积为500ml的圆底烧瓶4.2干燥柱：由宜径为20毫米的耐热玻璃层析柱和底部的耐热玻璃纤维组成注意：萃取时被污染的层析柱很难再次净化，现在市场上可以买到非玻璃层析柱,它是用•小块耐热玻璃棉垫来保存吸附剂，玻璃棉垫用润洗后再用50ml丙酗洗涤剂淸洗柱了和吸附剂.4.3 K-D装置4.3.1浓缩管10mh是从Konies K-57OO5O-IO25或同等设备改进而来.平而玻璃塞f用来防止萊取蒸干.4.3.2蒸僻瓶:500ml,连接有浓缩管，弹赘以及夹（与之类似设备.4.3.3斯耐徳柱带有三个微球4.3.4斯耐德柱带有两个微球4.3.5弹簧1/2英寸注总：在溶剂浓缩回收装置中，推荐使用K-D玻璃器件,组装这些部件并要满足当地政府所妥求的挥发性物质扌II：放标准的和关规定，美国环保署建议组装这些设备应与方法结合起来，从而达到降低押:放的目的•溶剂回收相当于废弃物最小限度排放以及污染控制.4.4溶剂回收系统（K-545000-1006 or K-547300-0000,优级玻璃6614-30.或等同物）4.5沸石溶剂萃取,可通过10/40网孔（碳化硅或等同物）4.6热水浴装置带有同心圆形盖，温度控制能力在±5'C,整个装置需要安装•外罩中.4.7小玻璃瓶2ml,带有聚四氟乙烯螺口上盖.4.8玻璃.纸质套管或玻璃棉无污染4.9加热套可变电阻控制4.10巴氏徳球形瓶，巴氏德管4.11干燥设备4.11.1烘箱温度保持在105°C4.11.2干燥器4.11.3堆圳陶瓷或铝材质4.12碾磨装置4.13分析天平精度0.000lg5.0试剂5.1所有的无机试剂级别都要经过验证，除非有美国化学联合会的简要说明书，其它级别的试剂也可能会用到，首先要确定这些试剂的纯度使之不会降低检测的准确度.5.2无机试剂水方法中所有的试剂参考第-章中无机试剂水的定义.5.3硫酸钠无水,粉末状，将其铺成•薄层，在4009加热净化4小时，或是用二氯甲烷进行清洗.经过二氯甲烷清洗过硫酸钠需要进行空白分析.以证明硫酸钠中不含有任何干扰.5.4萃取溶剂所有溶剂都必须匹配或是和类似.5.4.1土壤/沉积物以及淤泥都可以使用下列溶剂进行萃取：541」丙酮/己烷(l:l)(v/v) CH3COCH3/C6H14注意:这种萃取低毒低成本5.4.1.2 二氯甲烷炳酮(1:1 v/v) CH2C12/CH3COCH35.4.2其它样品可用下列溶剂萃取5.4.2.1二氯甲烷CH2C125.4.2.2甲苯/ 甲醇(10:l)(v/v) C6H5CH3/CH3OH5.5.1 己烷Hexane C6H145.5.2 2-丙醇(CH3)2CHOH5.5.3 环己烷C6H125.5.4 乙報CH3CN5.5替代溶剂所有的溶剂都应匹配或相类似6.0样品采集，保存，抽样.在这个章节主要介绍样品材料，有机分析在4.1中介绍.7.0步骤:7.1取样7.1.1沉积物/土壤样品倒沉积样品上而水层，充分地混匀，特别是复合样品，去除任何外来物质，如植物枝叶以及岩石等.7.1.2废弃物样品这种多相样品在萃取之前需要进行第二章中捉到的预处理过程. 这种萃取方法只针对固体样品.7.1.3废弃物样品灘磨碾磨细分后的样品可通过1mm滤网或是挤压通过1mm孔.碾磨后的样品质量至少要有10g.7.1.4橡胶，纤维或油性材料这些样品不需要碾磨，但要剪切成细统或小颗粒，使样品衣面积尽可能最人力I入与样品1:1比例的无水硫酸钠混合后,碾磨.7.2干燥后的样品比重当样品的测试结果以干样计算时,平行称取两份，在样品分析的同时，另外一份用于比重计算,注意：烘箱应该放置在•外罩中或通风口处，因为干燥过程是样品最主要的污染源. 样品称取后应立即进行萃取.称取5・10g样品于堆砌中，在105°C的温度下保持•个晚上, 要求称取之前在干燥器中冷却.样品的干重计算如下:••日•样品干燥过程完成后，用过的干燥器不能马上再次利用，而应该经过适当处理后才能投入使 用.7.3将10g 样品与10g 无水硫酸钠混合均匀后放入萃取容器中，索氏装置中的套管可以根据萃 取过程中玻璃棉上下样品的萃取能力，选择合适的套管.7.3.1 在样品中加入1.0ml 替代标准溶液（参考方法3500中关于参考物的描述） 7.3.2 针对每一批分析样品选取最强峰，加入1.0ml 参考溶液. 7.3.3参考方法3500的5.5和8.3选择合适的参考物及其浓度.7.4在500ml 的圆底烧瓶中加入300萃取溶剂（5.4）.同时加入1到2块沸石，连接烧瓶与抽提装 置，以每小时溶液循环4力周的速度连续萃取16-24小时.7.5萃取完成后要求萃取装置完成冷却.7.6将样品置于K-D 浓缩器，必要话将10ml 的浓缩管连在烧瓶上.7.7按照装置结构将回收溶剂的玻璃装置（冷凝器，接收器）与K-D 斯奈德层析柱联接.7.8用含有10cm 无水硫酸钠的干燥柱干燥萃取装置，将干燥过的萃取装置与K-D 装置联接后, 用100到125ml 的萃取液淸洗萃取烧瓶以及硫酸钠干燥柱等定量转移容器.7.9在烧瓶中加入1~2块沸石后与三孔斯耐德联接，从斯耐德柱的上端加入约lml 二氯甲烷进 行润洗，将K-D 装置置于水浴锅上（温度高于溶剂沸点15-20左右）使浓缩管浸入在热水中, 整个圆底烧瓶的衣面约处在水浴蒸汽中，调整设备位置以及合适的温度.按照耍求浓缩 10~20min.以•定的速率提取，但不外溢，当液体体积达到l~2ml 时.从水浴锅上移开K-D 装 置，至少冷却lOmin.7.10如果需要更换溶剂,（如衣1所示），立即移开斯耐徳柱，加入人约50ml 的更换溶剂以及新的沸 石,重新接好仪器.按照7.9浓缩萃取液，必要的话升高温度进行蒸係.当浓缩体积再次达到 l~2ml 时，从水浴锅上移开K ・D 装置，至少冷却lOmin.7.11移开斯耐德柱并且用卜2ml 的二氯甲烷或更换溶剂冲洗圆底烧瓶及浓缩管,如果出现硫磺 结晶，则应用方法3660淸理，应用7.12所描述的方法对萃取液进•步浓缩,用溶剂稀释至 10ml.7.12进•步的浓缩如衣1所示，无论是微斯耐徳柱技术（7.12.1）或是氮粉碎技术（7.12.2）都能满足 最终的萃取要求.7.12.1微斯耐德柱技术7.12.1.1在浓缩管中加入1~2块沸石，连二口的微斯耐德柱，从柱端加入0.5ml 二氯甲烷或萃 取溶剂润洗斯耐德柱.将K-D 装置放入到热水浴中使浓缩管部分浸入水中,调整仪 器位置以及水的温度，浓缩5-10min.在不外溢的情况下以•定的速率抽扌是.7.12.1.2当液体体积达到0.5ml 时.从水浴锅上移开K-D 装置，冷却lOmin,再移开斯耐德柱并 且用0.2ml 的溶剂冲洗烧瓶以及浓缩装置•最后将萃取液稀释至1.0~2.0ml,如衣1所 述.7.12.2氮粉碎技术7.12.2.1将浓缩装置置于温水浴中（人约35摄氏度）,利用清洁干燥的氮缓慢蒸发溶剂至•定体 积,（经活性炭柱过滤）.警告:在炭阱与样品之间不能使用塑料管，因为它可能会引入污染源.%干重干燥後的樣品質量 干燥前樣品質量7.12.2.2在分离的过程中管的内壁必须用合适的溶剂多次冲洗，在精谓过程中，应调整溶剂的液面高度防止水进入样品中（溶剂液而高度应该低于水浴高度），在正常的操作下，是不允许水浴锅变干的.警告:当溶剂的体积少于lml时，挥发性分析物可能有部分损失.7.13萃取是选用介适的有机溶剂对目标物进行分析的技术（参考本章4.3）,如果萃取分析不能立即完成，则打开浓缩管盖使之冷却.如果萃取液储存时间超过2天，应该将其转入带有特氟隆瓶塞的螺口玻璃瓶中，适当分类.8.0质量控制&1使用的任何空白试剂，基质或平行样品的处理过程应该与样品的分析程序相同.8.2参考第•章中的质量控制程序的具体细节，以及方法3500中样品处理过程.9.0参考方法如方法中所述10.0参考无农1不同举取方法萃取状况描述a.对所有方法而言,建议分析最佳体积是lO.OmL当液体体积为1.0m】时,达到侦测极限范围.b.方法8041中,1.0ml的2•甲醇萃取后用GC/FID分析样品中的苯酚，同时8041也包含另外•种分析程序，即用0.5ml的己烷萃取后，上GC/ECD分析.c.有必要的话•对GC/MS的萃取样品进行•净化•参考方法3600中的净化程序.方法3540索氏萃取开始结束萃取过程。

EPA方法索引EPA（Environmental Protection Agency，环境保护局）是美国联邦政府机构，负责制定环境保护政策和监督执行，旨在保护人类健康和自然环境。

EPA通过开发和更新一系列的方法和准则来评估和监测环境中的各种污染物。

以下是EPA方法的索引，其中包含了一些常用的方法。

1.水质分析方法：-EPA方法6010：使用电感耦合等离子体质谱仪对水样中的重金属进行测定。

-EPA方法160.2：测定饮用水中总溶解性氟化物的浓度。

-EPA方法200.7：使用火焰原子吸收光谱法测定水样中的金属。

-EPA方法365.2：测定地下水中40种有机化合物的浓度。

2.大气质量监测方法：-EPA方法305：测定大气中颗粒物（PM10）的质量浓度。

-EPA方法1664：对水和底泥中的油脂进行提取和测定。

-EPA方法321.8：通过气浓度梯度法测定大气中的苯系化合物。

-EPA方法327：使用红外光谱法测定大气中的多环芳烃。

3.土壤和底泥分析方法：-EPA方法3540：对土壤和底泥中的有机物进行提取。

-EPA方法8000：使用气相色谱质谱法分析土壤和底泥中的挥发性有机化合物。

-EPA方法3051：测定土壤样品中重金属的浓度。

-EPA方法8240：使用气相色谱质谱法分析土壤和底泥中的半挥发性有机化合物。

4.垃圾和固体废物分析方法：-EPA方法8015：使用气相色谱质谱法分析固体废物中的多环芳烃。

-EPA方法8082：使用气相色谱质谱法分析土壤、底泥和固体废物中的戴奥辛和类似化合物。

-EPA方法8260：使用气相色谱质谱法分析固体废物中的挥发性有机化合物。

-EPA方法8280：使用气相色谱质谱法分析固体废物中的多氯联苯。

5.生物监测方法：-EPA方法1600：测定饮用水和海水中的大肠杆菌和肠球菌数量。

-EPA方法1613：使用液相色谱质谱法测定鱼类组织中的多氯联苯和多溴联苯醚。

-EPA方法2050：测定水和生物体中蓝绿藻的数量和类群组成。

美国环保署（EPA）对炼油厂废气排放管理的启示1 美国环保署对炼油厂废气排放的主要管理方式美国环保署自2000年前就对美国炼油厂SO2和NO x排放制定了强制要求: “新污染源的排放执行标准”(New Source Performance Standards，简称 NSPS)，NSPS要求每个催化裂化装置必须满足排放要求，任何需要提高产能的催化裂化装置，均需要重新向环保署申请并获得批准，扩能获得批准后会执行更为严苛的排放标准。

2000年左右，美国环保署发现美国的催化裂化产能增加很多，但几乎没有炼厂提出申请，美国环保署质疑炼厂通过“消除瓶颈”的借口“逐步”提高产能，而不是采用一次性扩能，因此美国环保署对每个炼厂单独制定了SO2和NO x的排放标准，称为“许可法令”（Consent Decree简称CD）。

这些排放标准非常苛刻，但美国环保署并未强制炼油厂使用何种方法达到标准，而是允许采用各种手段满足排放标准。

至今EPA已经与32家美国炼油公司签署控制排放的“许可法令”，这32家公司的炼油能力占美国总炼油能力的90%，EPA目前仍在与一些炼油公司进行协商，这些公司约占美国炼油能力的5%，对于其余炼油公司，EPA正在对它们进行调查（见图1）。

图1 签署“许可法令”的美国炼油厂分布自从EPA与炼油公司签署“许可法令”以后，炼油公司用于控制排放技术项目的总投资超过60亿美元，因未达标上缴的罚款超过8000万美元，追加的环境项目投资超过7500万美元.与1999年相比，2011年美国炼油厂中催化裂化装置、硫磺回收装置、加热炉、锅炉和火炬的排放中总计减少超过93000吨/年的SO2和超过256000吨/年的NO x，比“许可法令”前的SO2和NO x排放量减少了75%（见图2）。

图2 美国炼油厂SO2和NO x减排情况美国119套催化裂化装置中，已经有104套装置在“许可法令”的控制范围内，其中有82套装置（占104套催化裂化总能力的81%）的SO2长期控制目标（一年排放平均值）为25ppm、短期控制目标（一周排放平均值）为50ppm。

EPA方法索引根据您的要求，以下是EPA（美国环保局）使用的一些常见的方法索引。

这些方法涵盖了环境监测、风险评估、废物管理、空气质量评估和水质评估等各个领域。

请注意，这只是一个简要的索引，详细的方法描述和操作程序可以在EPA的官方网站上找到。

1.环境监测方法：-EPA方法1：样品获取和保留方法-EPA方法2：采样口和尾气采集系统评估方法-EPA方法3：抽样方法-EPA方法4：大气沉降物的抽样和分析方法-EPA方法5：大气礁石沉积物中颗粒物的采样和分析方法-EPA方法6：大气颗粒物的测定方法-EPA方法7：废气流中氮氧化物的测定方法-EPA方法8：高温、高湿废气流中苯/甲苯浓度的测定方法2.风险评估方法：-EPA方法9：风险评估基础指南-EPA方法10：风险评估的质量保证3.废物管理方法：-EPA方法11：可回收物品处理-EPA方法12：生物治理/垃圾填埋申请-EPA方法13：废物水处理系统操作4.空气质量评估方法：-EPA方法14：大气污染源排放计算-EPA方法15：大气质量模型基础指南-EPA方法16：大气氨浓度的测定方法-EPA方法17：大气细颗粒物的测定方法-EPA方法18：大气湿沉降物的收集和分析方法5.水质评估方法：-EPA方法19：水质评估基础指南-EPA方法20：废水处理工艺-EPA方法21：水样处理和分析方法-EPA方法22：饮用水质量监测这些方法索引只是EPA使用的一小部分方法。

EPA还有其他方法用于地下水监测、土壤污染评估、生物毒性评估和生态风险评估等。

为了确保准确性和合规性，使用这些方法时应仔细阅读相关的方法说明和操作程序，以确保正确的实施和数据采集。

生态环境监测常用epa方法使用指南生态环境监测是保障人类居住环境健康、促进可持续发展的重要手段。

而美国环境保护局（EPA）提出的监测方法被广泛应用于全球。

本文将详细介绍几种常用的EPA监测方法，帮助读者更好地理解和应用。

首先，我们来介绍EPA方法中最常用的VOCs（挥发性有机物）监测方法。

VOCs是一类对人体健康和环境产生不良影响的化学物质，如苯、甲苯等。

EPA方法中，常用的监测技术包括气相色谱-质谱联用仪（GC-MS）和气相色谱仪（GC）。

在进行VOCs监测时，首先需从空气或水样品中提取目标物质，然后使用GC-MS或GC进行定性定量分析。

这些方法具有高灵敏度和准确度，对于环境中微量VOCs的检测非常有效。

其次，来介绍一种常用的水质监测方法，即EPA的标准方法522（EPA Method 522）。

该方法主要用于分析水中的多环芳烃（PAHs）。

PAHs是一类常见的有害物质，源自燃烧过程和工业排放。

在EPA Method 522中，使用气相色谱-质谱联用仪（GC-MS）进行PAHs的检测。

该方法采用固相萃取技术，从水样中富集PAHs，并通过GC-MS进行定性定量分析。

通过该方法，我们可以快速准确地监测水体中PAHs的含量，为水环境管理和保护提供科学依据。

此外，EPA还提出了许多其他的监测方法，如EPA Method 1600和EPA Method 1623等，这些方法主要用于微生物的监测。

例如，EPAMethod 1600用于检测饮用水和环境水体中的大肠杆菌等肠道致病菌的存在。

该方法采用滤膜法，将水样过滤后，将菌落生长于兔肠上进行检测。

而EPA Method 1623则用于监测水中的肠道病毒，如腺病毒和诺沃克病毒。

这些方法操作简单、结果可靠，对于保障水质安全具有重要意义。

除了上述方法外，EPA还提供了许多其它环境监测方法，如大气颗粒物的监测方法、土壤重金属的监测方法等。

这些方法为环境保护部门、科研机构以及行业监管提供了重要的技术支持。

微波萃取-氣相色譜/質譜聯用儀檢測塑膠材料中的PBBs或PBDEs1 采用方法：US EPA3540C-20002 試劑和儀器設備2.1 試劑2.1.1丙酮(AR)，正己烷(AR) ，甲醇（AR）。

2.1.2 PBB&PBDE標準溶液2.1.3 萃取液(1:1丙酮:正己烷)2.2 儀器設備2.2.1分析天平（精確至0.0001g）2.2.2 過濾針筒（濾膜0.45um）2.2.3 索氏萃取系統2.2.4 氣相色譜/質譜聯用儀（GC-MS）3前處理：3.1用剪刀將樣品盡可能地剪碎至約1mm*1mm*1mm大小，稱取1.000g樣品進行萃取，並平行做8次。

3.2 將樣品依據《3540C作業規范》進行萃取操作。

4方法曲線配制1.0mg/l, 3mg/l, 5.0mg/l的10-PBDE標准溶液建立曲線，方程為：10-PBDE : y =61412.8x, 相關係數γ為0.9959。

5方法回收率稱取1.0000g PBT塑膠樣品(SY7100501)加入1ml25mg/l的標准溶液按3要求前處理後檢測，其結果如下：回收率=(加標測量值-樣品測量)/加標量6.0方法檢出限(mg/kg)因報出結果為總含量PBB(多溴聯苯)和PBDE(多溴聯苯醚)，所以檢測限之核算取該類物質的最大標准偏差放大3倍再乘以種類數作為方法檢出限，即PBB檢出限為0.018×3×3= 0.17mg/kg , PBDE檢出限為0.007×3×4=0.08mg/kg。

為確保結果更加安全，本中心檢測限暫定為5mg/kg,以該濃度除以數量較多的聯苯醚種類(4種)進行驗證(5mg/kg÷4=1.25mg/kg)，取1mg/kg濃度進行驗證，其結果如下：標准偏差：0.11；平均值為：1.033；回收率：103.3%；相對標准偏差10.6%標准偏差：0.079；平均值：0.993；回收率：99.3%；相對標准偏差7.9%標准偏差0.091；平均值0.965；回收率96.5%：相對標准偏差9.43%標准偏差0.13；平均值0.985；回收率98.5%：相對標准偏差13.2%標准偏差0.155；平均值0.989；回收率98.9%：相對標准偏差15.7%標准偏差0.096；平均值1.018；回收率101.8%：相對標准偏差9.4%標准偏差0.127；平均值0.957；回收率95.7%：相對標准偏差13.3%7．結論由以上統計分析結果得知，本中心采用US EPA3540C方法前處理，GC/MS檢測塑膠材料中的多溴聯苯和多溴聯苯醚，回收率符合標准70～130%的要求；檢出限驗證RSD<20%(符合US EPA8000中8.3.1的要求)，方法可行。

美国国家环保局EPA方法要点和推荐仪器EPA方法218.6离子色谱测定在饮用水、地下水和工业废水中的水溶性铬（1994年修订版3.3）应用范围测定饮用水、地下水和工业废水中的水溶性六价铬（如CrO2-4），这种方法的检测下限为0.4μg/L。

样品中如果含有大量的阴离子物质如硫酸或氯离子可能会引起色谱柱过载。

样品如果含有大量有机物或硫离子可能会引起可溶性的六价铬快速还原为三价铬。

样品贮存在4℃，在24小时内分析。

方法采用离子色谱法分析。

方法要点：水样经0.45μm滤膜过滤后，用浓缓冲溶液调节pH为9-9.5。

样品的测量体积为50-250μL进样到离子色谱。

保护柱去除样品中的有机物，六价铬以CrO2-4形式，在高容量的阴离子交换分离柱上分离，六价铬用双苯基苄巴脲柱后衍生，然后在530nm波长下检测有色络合物。

建议采用的仪器条件保护柱：Dionex IonPac NG1或与之相同的色谱柱分离柱：Dionex IonPac AS7或与之相同的色谱柱阴离子抑制器装置：Dionex Anion MicroMembrane Suppressor，其它抑制器必须有足够低的检测限和足够的基线稳定性。

色谱条件：色谱柱：保护柱-Dionex IonPac NG1, 分离柱-Dionex IonPac AS7淋洗液：250mM (NH4)2SO4, 100mM NH4OH, 流速=1.5 mL/min柱后试剂：2mM双苯基苄巴脲，10％ v/v甲醇，1N 硫酸，流速=0.5 mL/min 检测器：可见光530nm保留时间：3.8 分钟离子色谱测定无机阴离子(1993年八月，修订版2.2)应用范围1．可测定的阴离子包括A部分：溴离子，氯离子，氟离子，硝酸根，亚硝酸根，磷酸根，硫酸B部分：溴酸根，亚氯酸根，氯酸根2．基体包括：饮用水，地表水，民用水和工业废水，地下水，试剂用水，固体浸出液方法要点1．小量样品，一般2-3mL注入离子色谱，阴离子采用一个系统含有保护柱，分离柱，抑制器和电导检测器进行分离和检测。

METHOD 3550CULTRASONIC EXTRACTIONSW-846 is not intended to be an analytical training manual. Therefore, method procedures are written based on the assumption that they will be performed by analysts who are formally trained in at least the basic principles of chemical analysis and in the use of the subject technology.In addition, SW-846 methods, with the exception of required method use for the analysis of method-defined parameters, are intended to be guidance methods which contain general information on how to perform an analytical procedure or technique which a laboratory can use as a basic starting point for generating its own detailed Standard Operating Procedure (SOP), either for its own general use or for a specific project application. The performance data included in this method are for guidance purposes only, and are not intended to be and must not be used as absolute QC acceptance criteria for purposes of laboratory accreditation.1.0SCOPE AND APPLICATION1.1This method describes a procedure for extracting nonvolatile and semivolatile organic compounds from solids such as soils, sludges, and wastes. The ultrasonic process ensures intimate contact of the sample matrix with the extraction solvent.1.2This method is divided into two procedures, based on the expected concentration of organic compounds. The low concentration procedure (Sec. 11.3) is for individual organic components expected at less than or equal to 20 mg/kg and uses the larger sample size and three serial extractions (lower concentrations are more difficult to extract). The medium/high concentration procedure (Sec. 11.4) is for individual organic components expected at greater than 20 mg/kg and uses the smaller sample and a single extraction.1.3It is highly recommended that the extracts be subject to some form of cleanup(e.g., using a method from the 3600 series) prior to analysis.1.4Because of the limited contact time between the solvent and the sample, ultrasonic extraction may not be as rigorous as other extraction methods for soils/solids. Therefore, it is critical that the method (including the manufacturer's instructions) be followed explicitly, in order to achieve the maximum extraction efficiency. See Sec. 11.0 for a discussion of the critical aspects of the extraction procedure. Consult the manufacturer's instructions regarding specific operational settings.1.5This method describes at least three extraction solvent systems that may be employed for different groups of analytes (see Sec. 7.4). Other solvent systems may be employed, provided that adequate performance can be demonstrated for the analytes of interest. The choice of extraction solvent will depend on the analytes of interest and no single solvent is universally applicable to all analyte groups. As a result of concerns about the efficiency of ultrasonic extraction, particularly at concentrations near or below about 10 µg/kg, it is imperative that the analyst demonstrate the performance of the specific solvent system and operating conditions for the analytes of interest and the concentrations of interest. This demonstration applies to any solvent system that is employed, including those specifically listed in this method. At a minimum, such a demonstration will encompass the initial demonstration of proficiency described in Method 3500, using a clean reference matrix. Method 8000 describesprocedures that may be used to develop performance criteria for such demonstrations as well as for matrix spike and laboratory control sample results.1.6EPA notes that there are limited published data on the efficiency of ultrasonic extraction with regard to organophosphorus pesticides at low part-per-billion (ppb) concentrations and below. As a result, use of this method for these compounds in particular should be supported by performance data such as those discussed above and in Method 3500.1.7Prior to employing this method, analysts are advised to consult the base method for each type of procedure that may be employed in the overall analysis (e.g., Methods 3500, 3600, 5000, and 8000) for additional information on quality control procedures, development of QC acceptance criteria, calculations, and general guidance. Analysts also should consult the disclaimer statement at the front of the manual and the information in Chapter Two for guidance on the intended flexibility in the choice of methods, apparatus, materials, reagents, and supplies, and on the responsibilities of the analyst for demonstrating that the techniques employed are appropriate for the analytes of interest, in the matrix of interest, and at the levels of concern.In addition, analysts and data users are advised that, except where explicitly specified in a regulation, the use of SW-846 methods is not mandatory in response to Federal testing requirements. The information contained in this method is provided by EPA as guidance to be used by the analyst and the regulated community in making judgments necessary to generate results that meet the data quality objectives for the intended application.1.8Use of this method is restricted to use by, or under the supervision of, appropriately experienced and trained analysts. Each analyst must demonstrate the ability to generate acceptable results with this method. As noted above, such demonstrations are specific to the analytes of interest and the solvent system used, as well as to the procedures for low and medium/high concentration samples.2.0SUMMARY OF METHOD2.1Low concentration procedure -- The sample is mixed with anhydrous sodium sulfate to form a free-flowing powder. The mixture is extracted with solvent three times, using ultrasonic extraction. The extract is separated from the sample by vacuum filtration or centrifugation. The extract is ready for final concentration, cleanup, and/or analysis.2.2Medium/high concentration procedure -- The sample is mixed with anhydrous sodium sulfate to form a free-flowing powder. This is extracted with solvent once, using ultrasonic extraction. A portion of the extract is collected for cleanup and/or analysis.3.0DEFINITIONSRefer to Chapter One and the manufacturer's instructions for definitions that may be relevant to this method.4.0INTERFERENCES4.1Solvents, reagents, glassware, and other sample processing hardware may yield artifacts and/or interferences to sample analysis. All of these materials must be demonstrated to be free from interferences under the conditions of the analysis by analyzing method blanks.Specific selection of reagents and purification of solvents by distillation in all-glass systems may be necessary. Refer to each method to be used for specific guidance on quality control procedures and to Chapter Four for general guidance on the cleaning of glassware.4.2Interferences are usually specific to the analytes of interest. Therefore, refer to Method 3500 and the appropriate determinative methods for specific guidance on extraction interferences.5.0SAFETYThis method does not address all safety issues associated with its use. The laboratory is responsible for maintaining a safe work environment and a current awareness file of OSHA regulations regarding the safe handling of the chemicals listed in this method. A reference file of material safety data sheets (MSDSs) should be available to all personnel involved in these analyses.6.0EQUIPMENT AND SUPPLIESThe mention of trade names or commercial products in this manual is for illustrative purposes only, and does not constitute an EPA endorsement or exclusive recommendation for use. The products and instrument settings cited in SW-846 methods represent those products and settings used during method development or subsequently evaluated by the Agency. Glassware, reagents, supplies, equipment, and settings other than those listed in this manual may be employed provided that method performance appropriate for the intended application has been demonstrated and documented.This section does not list common laboratory glassware (e.g., beakers and flasks).6.1Apparatus for grinding dry waste samples.6.2Ultrasonic preparation -- A horn-type device equipped with a titanium tip, or a device that will give appropriate performance, must be used.6.2.1Ultrasonic disrupter -- The disrupter must have a minimum power wattageof 300 watts, with pulsing capability. A device designed to reduce the cavitation sound is recommended. Follow the manufacturers instructions for preparing the disrupter forextraction of samples with low and medium/high concentrations.6.2.2Use a 3/4-inch horn for the low concentration method procedure and a1/8-inch tapered microtip attached to a 1/2-inch horn for the medium/high concentration method procedure.6.3Sonabox -- Recommended with the above disrupters for decreasing cavitation sound (Heat Systems - Ultrasonics, Inc., Model 432B or equivalent).6.4Apparatus for determining percent dry weight6.4.1Drying oven -- Capable of maintaining 105 E C.6.4.2Desiccator.6.4.3Crucibles -- Porcelain or disposable aluminum.6.5Pasteur pipets -- 1-mL, glass, disposable.6.7Vacuum or pressure filtration apparatus6.7.1Buchner funnel6.7.2Filter paper -- Whatman No. 41 or equivalent.6.8Kuderna-Danish (K-D) apparatus6.8.1Concentrator tube -- 10-mL, graduated (Kontes K-570050-1025 orequivalent). A ground-glass stopper is used to prevent evaporation of extracts.6.8.2Evaporation flask -- 500-mL (Kontes K-570001-500 or equivalent). Attachthe flask to the concentrator tube with springs, clamps, or equivalent.6.8.3Snyder column -- Three-ball macro (Kontes K-503000-0121 orequivalent).6.8.4Snyder column -- Two-ball micro (Kontes K-569001-0219 or equivalent).6.8.5Springs -- 1/2-inch (Kontes K-662750 or equivalent).6.9Solvent vapor recovery system (Kontes K-545000-1006 or K-547300-0000, Ace Glass 6614-30, or equivalent).NOTE:This glassware is recommended for the purpose of solvent recovery during the concentration procedures requiring the use of Kuderna-Danish evaporativeconcentrators. Incorporation of this apparatus may be required by Federal, State orlocal municipality regulations that govern air emissions of volatile organics. EPArecommends the incorporation of this type of reclamation system as a method toimplement an emissions reduction program. Solvent recovery is a means to conformwith waste minimization and pollution prevention initiatives.6.10Boiling chips -- Solvent-extracted, approximately 10/40 mesh (silicon carbide or equivalent).6.11Water bath -- Heated, with a concentric ring cover, capable of temperature control to ± 5 E C. The bath should be used in a hood.6.12Balance -- Top-loading, capable of accurately weighing to the nearest 0.01 g.6.13Vials -- 2-mL, for GC autosampler, equipped with polytetrafluoroethylene (PTFE)-lined screw caps or crimp tops.6.14Glass scintillation vials -- 20-mL, equipped with PTFE-lined screw caps.6.15Spatula -- Stainless steel or PTFE.6.16Drying column -- 20-mm ID borosilicate glass chromatographic column with glass wool at the bottom.NOTE:Columns with fritted glass discs are difficult to decontaminate after they have been used to dry highly-contaminated extracts. Columns without frits may be purchased.Use a small pad of glass wool to retain the adsorbent. Prewash the glass wool padwith 50 mL of acetone followed by 50 mL of the elution solvent prior to packing thecolumn with adsorbent.6.17Nitrogen evaporation apparatus (optional) -- N-Evap, 12- or 24-position(Organomation Model 112, or equivalent).7.0REAGENTS AND STANDARDS7.1Reagent-grade chemicals must be used in all tests. Unless otherwise indicated, it is intended that all reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. Reagents should be stored in glass to prevent the leaching of contaminants from plastic containers.7.2Organic-free reagent water. All references to water in this method refer to organic-free reagent water, as defined in Chapter One.7.3Sodium sulfate (granular, anhydrous), Na 2SO 4. Purify by heating at 400 E C for 4hrs in a shallow tray, or by precleaning the sodium sulfate with methylene chloride. If the sodium sulfate is precleaned with methylene chloride, a method blank should be analyzed,demonstrating that there is no interference from the sodium sulfate.7.4Extraction solventsSamples should be extracted using a solvent system that gives optimum, reproducible recovery of the analytes of interest from the sample matrix, at the concentrations of interest. The choice of extraction solvent will depend on the analytes of interest and no single solvent is universally applicable to all analyte groups. Whatever solvent system is employed, including those specifically listed in this method, the analyst must demonstrate adequate performance for the analytes of interest, at the levels of interest. At a minimum, such a demonstration will encompass the initial demonstration of proficiency described in Method 3500, using a cleanreference matrix. Method 8000 describes procedures that may be used to develop performance criteria for such demonstrations as well as for matrix spike and laboratory control sample results.Many of the solvent systems described below include the combination of a water-miscible solvent, such as acetone, and a water-immiscible solvent, such as methylene chloride orhexane. The purpose of the water-miscible solvent is to facilitate the extraction of wet solids by allowing the mixed solvent to penetrate the layer of water of the surface of the solid particles. The water-immiscible solvent extracts organic compounds with similar polarities. Thus, a non-polar solvent such as hexane is often used for non-polar analytes such as PCBs, while a polar solvent like methylene chloride may be used for polar analytes. The polarity of acetone may also help extract polar analytes in mixed solvent systems.Table 1 provides example recovery data for selected semivolatile organic compounds extracted from an NIST SRM using various extraction solvent systems. The following sections provide guidance on the choice of solvents for various classes of analytes.All solvents should be pesticide quality or equivalent. Solvents may be degassed prior to use.7.4.1Semivolatile organics may be extracted with acetone/hexane (1:1, v/vCH 3COCH 3/C 6H 14), or acetone/methylene chloride (1:1,v/v CH 3COCH 3/CH 2Cl 2).7.4.2Organochlorine pesticides may be extracted with acetone/hexane (1:1,v/v CH 3COCH 3/C 6H 14), or acetone/methylene chloride (1:1,v/v CH 3COCH 3/CH 2Cl 2).7.4.3PCBs may be extracted with acetone/hexane (1:1, v/v CH 3COCH 3/C 6H 14),acetone/methylene chloride (1:1, v/v CH 3COCH 3/CH 2Cl 2) or hexane (C 6H 14).7.4.4Other solvent systems may be employed, provided that the analyst candemonstrate adequate performance for the analytes of interest, at the concentrations of interest, in the sample matrix (see Method 3500).7.5Exchange solvents -- With the use of some determinative methods, the extraction solvent will need to be exchanged to a solvent compatible with the instrumentation used in that determinative method. Refer to the determinative method to be used for selection of theappropriate exchange solvent. All solvents must be pesticide quality or equivalent. Examples of exchange solvents are given below.7.5.1Hexane, C 6H 147.5.22-Propanol, (CH 3)2CHOH 7.5.3Cyclohexane, C 6H 127.5.4Acetonitrile, CH 3CN 7.5.5Methanol, CH 3OH 8.0SAMPLE COLLECTION, PRESERVATION, AND STORAGE8.1See the introductory material to Chapter Four, "Organic Analytes," Method 3500,and the specific determinative methods to be employed.8.2Solid samples to be extracted by this procedure should be collected and stored like any other solid samples containing semivolatile organics.9.0QUALITY CONTROL9.1Refer to Chapter One for additional guidance on quality assurance (QA) andquality control (QC) protocols. When inconsistencies exist between QC guidelines, method-specific QC criteria take precedence over both technique-specific criteria and those criteria given in Chapter One, and technique-specific QC criteria take precedence over the criteria in Chapter One. Any effort involving the collection of analytical data should include development of a structured and systematic planning document, such as a Quality Assurance Project Plan (QAPP) or a Sampling and Analysis Plan (SAP), which translates project objectives andspecifications into directions for those that will implement the project and assess the results. Each laboratory should maintain a formal quality assurance program. The laboratory should also maintain records to document the quality of the data generated. All data sheets and quality control data should be maintained for reference or inspection.9.2Initial demonstration of proficiencyEach laboratory must demonstrate initial proficiency with each sample preparation and determinative method combination it utilizes by generating data of acceptable accuracy and precision for target analytes in a clean matrix. The laboratory must also repeat the demonstration of proficiency whenever new staff members are trained or significant changes in instrumentation are made. See Method 8000 for information on how to accomplish a demonstration of proficiency.9.3Initially, before processing any samples, the analyst should demonstrate that all parts of the equipment in contact with the sample and reagents are interference-free. This is accomplished through the analysis of a method blank. As a continuing check, each time samples are extracted, cleaned up, and analyzed, and when there is a change in reagents, a method blank should be extracted and analyzed for the compounds of interest as a safeguard against chronic laboratory contamination.9.4Any method blanks, matrix spike samples, or replicate samples should be subjected to the same analytical procedures (Sec. 11.0) as those used on actual samples.9.5Standard quality assurance practices should be used with this method as included in appropriate systematic planning documents and laboratory SOPs. All instrument operating conditions should be recorded.9.6Also refer to Method 3500 for extraction and sample preparation quality control procedures and the determinative methods to be used for determinative QC procedures.9.7When listed in the appropriate determinative method, surrogate standards should be added to all samples prior to extraction. See Methods 3500 and 8000, and the appropriate determinative methods for more information.9.8As noted earlier, use of any extraction technique, including ultrasonic extraction, should be supported by data that demonstrate the performance of the specific solvent system and operating conditions for the analytes of interest, at the levels of interest, in the sample matrix.10.0CALIBRATION AND STANDARDIZATIONThere are no calibration or standardization steps directly associated with this sample extraction procedure.11.0PROCEDUREAs noted in Sec. 1.4, ultrasonic extraction may not be as rigorous a method as other extraction methods for soils/solids. Therefore, it is critical that this method be followed explicitly (including the manufacturer's instructions) to achieve the maximum extraction efficiency. At a minimum, for successful use of this technique:•The extraction device must have a minimum of 300 watts of power and be equipped with appropriate size disrupter horns (see Sec. 6.2).•The horn must be properly maintained, including tuning according to the manufacturer's instructions prior to use, and inspection of the horn tip for excessive wear.•The sample must be properly prepared by thoroughly mixing it with sodium sulfate, so that it forms a free-flowing powder prior to the addition of the solvent.•The extraction horns used for the low concentration and high concentration protocols (Secs. 11.3 and 11.4, respectively) are not interchangeable. Results indicate that the use of the 3/4-inch horn is inappropriate for the high concentration procedure, particularly for extraction of very non-polar organic compounds such as PCBs, which are stronglyadsorbed to the soil matrix.•For low concentration samples, three extractions are performed with the appropriate solvent, the extraction is performed in the designated pulse mode, and the horn tip ispositioned just below the surface of the solvent, yet above the sample. The sameapproach is used for high concentration samples, except that only one extraction may be needed.•Very active mixing of the sample and the solvent must occur when the ultrasonic pulse is activated. The analyst must observe such mixing at some point during the extractionprocess.11.1Sample handling11.1.1Sediment/soil samples -- Decant and discard any water layer on asediment sample. Discard any foreign objects such as sticks, leaves, and rocks. Mix the sample thoroughly, especially composited samples.11.1.2Waste samples -- Samples consisting of multiple phases must beprepared before extraction by the phase separation procedure described in Chapter Two.This extraction procedure is for solids only.11.1.3Dry waste samples amenable to grinding -- Grind or otherwise subdividethe waste so that it either passes through a 1-mm sieve or can be extruded through a 1-mm hole. Introduce sufficient sample into the grinding apparatus to yield at least 10 gafter grinding.CAUTION:Drying and grinding should be performed in a hood, to avoid contamination of the laboratory.11.1.4Gummy, fibrous, or oily materials not amenable to grinding -- Cut, shred,or otherwise reduce in size these materials to allow mixing and maximum exposure of the sample surfaces for the extraction.11.2Determination of percent dry weight -- When sample results are to be calculated ona dry weight basis, a separate portion of sample should be weighed out at the same time as the portion used for analytical determination.CAUTION:The drying oven should be contained in a hood or vented. Significant laboratory contamination may result from a heavily contaminated hazardous waste sample.Immediately after weighing the sample aliquot to be extracted, weigh an additional 5- to10-g aliquot of the sample into a tared crucible. Dry this aliquot overnight at 105 E C. Allow to cool in a desiccator before weighing.Calculate the percent dry weight as follows:%dry weight'g of dry sampleg of sample×100This oven-dried aliquot is not used for the extraction and should be appropriately disposed of once the dry weight is determined.11.3Low concentration extraction procedureThis procedure applies to solid samples that are expected to contain less than or equal to 20 mg/kg of organic analytes.NOTE:Add the surrogates and matrix spiking compounds to the sample aliquot prior to mixing the sample with the sodium sulfate drying agent. Spiking the sample first increasesthe contact time of the spiked compounds and the actual sample matrix. It should also lead to better mixing of the spiking solution with the sample when the sodium sulfateand sample are mixed to the point of free-flowing.11.3.1The following steps should be performed rapidly to avoid loss of the morevolatile extractables.11.3.1.1Weigh approximately 30 g of sample into a 400-mL beaker.Record the weight to the nearest 0.1 g.11.3.1.2For the sample in each batch selected for spiking, add 1.0 mLof the matrix spiking solution. Consult Method 3500 for guidance on theappropriate choice of matrix spiking compounds and concentrations. Also see thenote in Sec. 11.3.11.3.1.3Add 1.0 mL of the surrogate standard solution to all samples,spiked samples, QC samples, and blanks. Consult Method 3500 for guidance onthe appropriate choice of surrogate compounds and concentrations. Also see thenote in Sec. 11.3.11.3.1.4If gel permeation cleanup (see Method 3640) is to beemployed, the analyst should either add twice the volume of the surrogate spikingsolution (and matrix spiking solution, where applicable), or concentrate the finalextract to half the normal volume, to compensate for the half of the extract that islost due to loading of the GPC column. Also see the note in Sec. 11.3.11.3.1.5Nonporous or wet samples (gummy or clay type) that do nothave a free-flowing sandy texture must be mixed with 60 g of anhydrous sodiumsulfate, using a spatula. If needed, more sodium sulfate may be added. Afteraddition of sodium sulfate, the sample should be free flowing. Also see the note inSec. 11.3.11.3.1.6Immediately add 100 mL of the extraction solvent or solventmixture (see Sec. 7.4 and Table 2 for information on the choice of solvents).11.3.2Place the bottom surface of the tip of the 3/4-inch disrupter horn about1/2-inch below the surface of the solvent, but above the sediment layer.NOTE:Be sure that the horn is properly tuned according to the manufacturer'sinstructions.11.3.3Extract the sample ultrasonically for 3 min, with output control knob set at10 (full power) or at the manufacturer’s recommended power setting, the mode switch onPulse (pulsing energy rather than continuous energy), and the percent-duty cycle knob set at 50% (energy on 50% of time and off 50% of time). Do not use the microtip probe.11.3.4Decant the extract and filter it through Whatman No. 41 filter paper (orequivalent) in a Buchner funnel that is attached to a clean 500-mL filtration flask.Alternatively, decant the extract into a centrifuge bottle and centrifuge at low speed toremove particles.11.3.5Repeat the extraction two more times with two additional 100-mL portionsof clean solvent. Decant off the solvent after each ultrasonic extraction. After the finalultrasonic extraction, pour the entire sample into the Buchner funnel, rinse the beaker with extraction solvent, and add the rinse to the funnel. Apply a vacuum to the filtration flask, and collect the solvent extract. Continue filtration until all visible solvent is removed from the funnel, but do not attempt to completely dry the sample, as the continued application of a vacuum may result in the loss of some analytes. Alternatively, if centrifugation is used in Sec. 11.3.4, transfer the entire sample to the centrifuge bottle. Centrifuge at low speed, and then decant the solvent from the bottle.11.3.6If necessary, concentrate the extract prior to analysis following theprocedure in Sec. 11.5. Otherwise, proceed to Sec. 11.7.11.4Medium/high concentration extraction procedureThis procedure applies to solid samples that are expected to contain more than 20 mg/kg of organic analytes.11.4.1Transfer approximately 2 g of sample to a 20-mL vial. Wipe the mouth ofthe vial with a tissue to remove any sample material. Cap the vial before proceeding with the next sample to avoid any cross-contamination. Record the weight to the nearest 0.1 g.11.4.2For the sample in each batch selected for spiking, add 1.0 mL of thematrix spiking solution. Consult Method 3500 for guidance on the appropriate choice of matrix spiking compounds and concentrations. Also see the note in Sec. 11.3.11.4.3Add 1.0 mL of surrogate spiking solution to all samples, spiked samples,QC samples, and blanks. Consult Method 3500 for guidance on the appropriate choice of matrix spiking compounds and concentrations. Also see the note in Sec. 11.3.11.4.4If gel permeation cleanup (see Method 3640) is to be employed, theanalyst should either add twice the volume of the surrogate spiking solution (and matrix spiking solution, where applicable), or concentrate the final extract to half the normalvolume, to compensate for the half of the extract that is lost due to loading of the GPCcolumn.11.4.5Nonporous or wet samples (gummy or clay type) that do not have a free-flowing sandy texture must be mixed with 2 g of anhydrous sodium sulfate, using aspatula. If needed, more sodium sulfate may be added. After addition of sodium sulfate, the sample should be free flowing (see the note in Sec. 11.3).。

METHOD 3545PRESSURIZED FLUID EXTRACTION (PFE)1.0SCOPE AND APPLICATION1.1 Method 3545 is a procedure for extracting water insoluble or slightly water soluble semivolatile organic compounds from soils, clays, sediments, sludges, and waste solids. The method uses elevated temperature (100E C) and pressure (1500 - 2000 psi) to achieve analyte recoveries equivalent to those from Soxhlet extraction, using less solvent and taking significantly less time than the Soxhlet procedure. This procedure was developed and validated on a commercially-available, automated extraction system.1.2This method is applicable to the extraction of semivolatile organic compounds, organophosphorus pesticides, organochlorine pesticides, chlorinated herbicides, and PCBs, which may then be analyzed by a variety of chromatographic procedures.1.3This method has been validated for solid matrices containing 250 to 12,500 µg/kg of semivolatile organic compounds, 250 to 2500 µg/kg of organophosphorus pesticides, 5 to 250 µg/kg of organochlorine pesticides, 50 to 5000 µg/kg of chlorinated herbicides, and 1 to 1400 µg/kg of PCBs. The method may be applicable to samples containing these analytes at higher concentrations and may be employed after adequate performance has been demonstrated for the concentrations of interest (see Method 3500, Sec. 8.0).1.4This method is applicable to solid samples only, and is most effective on dry materials with small particle sizes. Therefore, waste samples must undergo phase separation, as described in Chapter Two, and only the solid phase material is to be extracted by this procedure. If possible, soil/sediment samples may be air-dried and ground to a fine powder prior to extraction. Alternatively, if the loss of analytes during drying is a concern, soil/sediment samples may be mixed with anhydrous sodium sulfate or pelletized diatomaceous earth. The total mass of material to be prepared depends on the specifications of the determinative method and the sensitivity required for the analysis, but 10 - 30 g of material are usually necessary and can be accommodated by this extraction procedure.1.5This method is restricted to use by or under the supervision of trained analysts. Each analyst must demonstrate the ability to generate acceptable results with this method.2.0SUMMARY OF METHOD2.1Samples are prepared for extraction either by air drying the sample, or by mixing the sample with anhydrous sodium sulfate or pelletized diatomaceous earth. The sample is then ground to a 100 - 200 mesh powder (150 µm to 75 µm) and loaded into the extraction cell.2.2The extraction cell containing the sample is heated to the extraction temperature (see Sec. 7.8), pressurized with the appropriate solvent system, and extracted for 5 minutes (or as recommended by the instrument manufacturer). The solvent systems used for this procedure vary with the analytes of interest and are described in Sec. 5.5.2.3The solvent is collected from the heated extraction vessel and allowed to cool.CD-ROM3545 - 1Revision 0December 19962.4The extract may be concentrated, if necessary, and, as needed, exchanged into a solvent compatible with the cleanup or determinative step being employed.3.0INTERFERENCES3.1Refer to Method 3500.3.2If necessary, Florisil and/or sulfur cleanup procedures may be employed. In such cases, proceed with Method 3620 and/or Method 3660.4.0APPARATUS AND MATERIALS4.1Pressurized fluid extraction device4.1.1Dionex Accelerated Solvent Extractor or Supelco SFE-400 with appropriately-sized extraction cells. Currently, cells are available that will accommodate 10-g, 20-g and 30-g samples. Cells should be made of stainless steel or other material capable of withstanding the pressure requirements (2000+ psi) necessary for this procedure.4.1.2Other system designs may be employed, provided that adequate performancecan be demonstrated for the analytes and matrices of interest.4.2Apparatus for determining percent dry weight4.2.1Oven - drying4.2.2Desiccator4.2.3Crucibles - porcelain or disposable aluminum4.3Apparatus for grinding - capable of reducing particle size to < 1 mm.4.4Analytical balance - capable to weighing to 0.01 g.4.5Vials for collection of extracts - 40-mL or 60-mL, pre-cleaned, open top screw-cap with PTFE-lined silicone septum (Dionex 049459, 049460, 049461, 049462 or equivalent).4.6Filter disk - 1.91 cm, Type D28 (Whatman 10289356, or equivalent).4.7Cell cap sealing disk (Dionex 49454, 49455, or equivalent).5.0REAGENTS5.1Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.CD-ROM3545 - 2Revision 0December 1996CD-ROM 3545 - 3Revision 0December 19965.2Organic-free reagent water. All references to water in this method refer to organic-free reagent water, as defined in Chapter One.5.3Drying agents5.3.1Sodium sulfate (granular anhydrous), Na SO .245.3.2Pelletized diatomaceous earth.5.3.3The drying agents should be purified by heating at 400E C for 4 hours in a shallowtray, or by extraction with methylene chloride. If extraction with methylene chloride is employed, then a reagent blank should be prepared to demonstrate that the drying agent is free of interferences.5.4Phosphoric acid solution (see Sec. 5.5.5). Prepare a 1:1 (v/v) solution of 85% phosphoric acid (H PO ) in organic-free reagent water.345.5Extraction solventsThe extraction solvent to be employed depends on the analytes to be extracted, as described below. All solvents should be pesticide quality or equivalent. Solvents may be degassed prior to use.5.5.1Organochlorine pesticides may be extracted with acetone/hexane (1:1, v/v),CH COCH /C H or acetone/methylene chloride (1:1,v/v), CH COCH /CH Cl .33614 332 2 5.5.2Semivolatile organics may be extracted with acetone/methylene chloride (1:1,v/v), CH COCH /CH Cl or acetone/hexane (1:1, v/v), CH COCH /C H .3322 336145.5.3PCBs may be extracted with acetone/hexane (1:1, v/v), CH COCH /C H or33614acetone/methylene chloride (1:1, v/v), CH COCH /CH Cl or hexane, C H .3322 6145.5.4Organophosphorus pesticides may be extracted with methylene chloride, CH Cl 22or acetone/methylene chloride (11:1, v/v), CH COCH /CH Cl .33225.5.5Chlorinated herbicides may be extracted with an acetone/methylenechloride/phosphoric acid solution (250:125:15, v/v/v), CH COCH /CH Cl /H PO , or an 332234acetone/methylene chloride/trifluoroacetic acid solution (250:125:1, v/v/v),CH COCH /CH Cl /CF COOH. (If the second option is used, the trifluoroacetic acid solution 33223should be prepared by mixing 1% trifluoroacetic acid in acetonitrile.) Make fresh solutions before each batch of extractions.5.5.6Other solvent systems may be employed, provided that the analyst candemonstrate adequate performance for the analytes of interest in the sample matrix (see Method 3500, Sec. 8.0).CAUTION: For best results with very wet samples (e.g., $30% moisture), reduce oreliminate the quantity of hydrophilic solvent used.5.6High-purity gases such as nitrogen, carbon dioxide, or helium are used to purge and/or pressurize the extraction cell. Follow the instrument manufacturer's recommendation for the choice of gases.6.0SAMPLE COLLECTION, PRESERVATION, AND HANDLINGSee the introductory material to this chapter, Organic Analysis, Sec. 4.1.7.0PROCEDURE7.1Sample preparation7.1.1Sediment/soil samples - Decant and discard any water layer on a sedimentsample. Mix the sample thoroughly, especially composited samples. Discard any foreign objects such as sticks, leaves, and rocks. Air dry the sample at room temperature for 48 hours in a glass tray or on hexane-rinsed aluminum foil. Alternatively, mix the sample with an equal volume of anhydrous sodium sulfate or pelletized diatomaceous earth until a free-flowing powder is obtained.NOTE:Dry, finely-ground soil/sediment allows the best extraction efficiency for nonvolatile, nonpolar organics, e.g., 4,4'-DDT, PCBs, etc. Air-drying may notbe appropriate for the analysis of the more volatile organochlorine pesticides(e.g., the BHCs) or the more volatile of the semivolatile organics because oflosses during the drying process. The use of sodium sulfate as a dryingagent can lead to clogging of the frits in the cell with recrystallized sodiumsulfate. (See “Caution” following Sec. 5.5.6.)7.1.2Waste samples - Multiphase waste samples must be prepared by the phaseseparation method in Chapter Two before extraction. This extraction procedure is for solids only.7.1.3Dry sediment/soil and dry waste samples amenable to grinding. Grind orotherwise reduce the particle size of the waste so that it either passes through a 1-mm sieve or can be extruded through a 1-mm hole. Disassemble grinder between samples, according to manufacturer's instructions, and decontaminate with soap and water, followed by acetone and hexane rinses.NOTE:The note in Sec. 7.1.1 also applies to the grinding process.7.1.4Gummy, fibrous, or oily materials not amenable to grinding should be cut,shredded, or otherwise reduced in size to allow mixing and maximum exposure of the sample surfaces for the extraction. The analyst may add anhydrous sodium sulfate, pelletized diatomaceous earth, sand, or other clean, dry reagents to the sample to make it more amenable to grinding.7.2Determination of percent dry weight - When sample results are to be calculated on a dry weight basis, a second portion of sample should be weighed at the same time as the portion used for analytical determination.WARNING:The drying oven should be contained in a hood or vented. Significant laboratory contamination may result from drying a heavily contaminated sample.CD-ROM3545 - 4Revision 0December 1996%dry weight 'g of dry sample g of sample×100CD-ROM 3545 - 5Revision 0December 19967.2.1Immediately after weighing the sample for extraction, weigh 5 - 10 g of the sampleinto a tared crucible. Dry this aliquot overnight at 105E C. Allow to cool in a desiccator before weighing. Calculate the % dry weight as follows:7.3Grind a sufficient weight of the dried sample from Sec. 7.1 to yield the sample weight needed for the determinative method (usually 10 - 30 g). Grind the sample until it passes through a 10 mesh sieve.7.4Transfer the ground sample to an extraction cell of the appropriate size for the aliquot.Generally, an 11-mL cell will hold about 10 g of material, a 22-mL cell will hold about 20 g of material, and a 33-mL cell will hold about 30 g of material. The weight of a specific sample that a cell will contain depends on the bulk density of the sample and the amount of drying agent that must be added to the sample in order to make it suitable for extraction. Analysts should ensure that the sample aliquot extracted is large enough to provide the necessary sensitivity and choose the extraction cell size accordingly. Use disposable cellulose or glass fiber filters in the cell outlets.Clean sand may be used to fill any void volume in the extraction cells.7.5Add the surrogates listed in the determinative method to each sample. Add the matrix spike/matrix spike duplicate compounds listed in the determinative method to the two additional aliquots of the sample selected for spiking.7.6Place the extraction cell into the instrument or autosampler tray, as described by the instrument manufacturer.7.7Place a precleaned collection vessel in the instrument for each sample, as described by the instrument manufacturer. The total volume of the collected extract will depend on the specific instrumentation and the extraction procedure recommended by the manufacturer and may range from 0.5 to 1.4 times the volume of the extraction cell. Ensure that the collection vessel is sufficiently large to hold the extract.7.8Recommended extraction conditionsOven temperature:100E C Pressure:1500 - 2000 psi Static time:5 min (after 5 min pre-heat equilibration)Flush volume:60% of the cell volume Nitrogen purge:60 sec at 150 psi (purge time may be extended for larger cells)Static Cycles: 17.8.1Optimize the conditions, as needed, according to the manufacturer's instructions.In general, the pressure is not a critical parameter, as the purpose of pressurizing the extraction cell is to prevent the solvent from boiling at the extraction temperature and to ensure that the solvent remains in intimate contact with the sample. Any pressure in the range of 1500 - 2000 psi should suffice.7.8.2Once established, the same pressure should be used for all samples extractedfor the same analysis type.7.9Begin the extraction according to the manufacturer's instructions.7.10Collect each extract in a clean vial (see Sec. 7.7). Allow the extracts to cool after the extractions are complete.7.11The extract is now ready for concentration, cleanup, or analysis, depending on the extent of interferants and the determinative method to be employed. Refer to Method 3600 for guidance on selecting appropriate cleanup methods. Excess water present in extracts may be removed by filtering the extract through a bed of anhydrous sodium sulfate. Certain cleanup and/or determinative methods may require a solvent exchange prior to cleanup and/or sample analysis.7.12 If the phosphoric acid solution in Sec. 5.5.5 is used for the extraction of chlorinated herbicides, then the extractor should be rinsed by pumping acetone through all the lines of the system. The use of other solvents for these analytes may not require this rinse step.8.0QUALITY CONTROL8.1Refer to Chapter One and Method 8000 for guidance on quality control procedures. Refer to Method 3500 for specific guidance on extraction and sample preparation procedures.8.2Before processing any samples, the analyst should demonstrate that all parts of the equipment in contact with the sample and reagents are interference-free. This is accomplished through the analysis of a solid matrix method blank (e.g., clean sand). Each time samples are extracted, and when there is a change in reagents, a method blank needs to be extracted and analyzed for the compounds of interest. The method blank should be carried through all stages of the sample preparation and measurement.8.3Standard quality assurance practices should be used with this method. Field duplicates should be collected to validate the precision of the sampling procedures. A matrix spike/matrix spike duplicate, or matrix spike and duplicate sample analysis, and a laboratory control sample should be prepared and analyzed with each batch of samples prepared by this procedure, unless the determinative method provides other guidance.8.4Surrogate standards should be added to all samples when listed in the appropriate determinative method.9.0METHOD PERFORMANCE9.1Chlorinated pesticides and semivolatile organicsSingle-laboratory accuracy data were obtained for chlorinated pesticides and semivolatile organics at three different spiking concentrations in three different soil types. Spiking concentrations ranged from 5 to 250 µg/kg for the chlorinated pesticides and from 250 to 12500 µg/kg for the semivolatiles. Spiked samples were extracted both by the Dionex Accelerated Solvent Extraction system and by a Perstorp Environmental Soxtec™ (automated Soxhlet). Extracts were analyzed either by Method 8270 or Method 8081. Method blanks, spikes and spike duplicates were included for the low concentration spikes; matrix spikes were included for all other concentrations. The data are reported in detail in Reference 1, and represent seven replicate extractions and analyses for each sample. Data summary tables are included in Methods 8270 and 8081.CD-ROM3545 - 6Revision 0December 19969.2Organophosphorus pesticides and chlorinated herbicidesSingle-laboratory accuracy data were obtained for organophosphorus pesticides (OPPs) and chlorinated herbicides at two different spiking concentrations in three different soil types. Spiking concentrations ranged from 250 to 2500 µg/kg for the OPPs and from 50 to 5000 µg/kg for the chlorinated herbicides. Chlorinated herbicides were spiked with a mixture of the free acid and the ester (1:1). Spiked samples were extracted both by the Dionex Accelerated Solvent Extractor and by Soxhlet for the OPPs. Extracts were analyzed by Method 8141. Spiked chlorinated herbicides were extracted by the Dionex Accelerated Solvent Extractor and by the shaking method described in Method 8151. Extracts were analyzed by Method 8151. Method blanks, spikes and spike duplicates were included for the low concentration spikes; matrix spikes were included for all other concentrations. The data are reported in detail in Reference 2, and represent seven replicate extractions and analyses for each sample. Data summary tables are included in Methods 8141 and 8151.9.3PCBsSingle-laboratory accuracy data were obtained for PCBs from a soil sample with PCB content certified by NIST (Standard Reference Material, SRM 1939, River Sediment). A PCB-contaminated soil was purchased from a commercial source. Spiking or certified concentrations ranged from 1 to 1400 µg/kg. Samples were extracted by the Dionex Accelerated Solvent Extractor and by Soxtec™(Perstorp Environmental). Extracts were analyzed using Method 8082. Method blanks, spikes and spike duplicates were included. The data are reported in Reference 2, and represent seven replicate extractions and analyses for each sample. Data summary tables are included in Method 8082. 10.0REFERENCES1. B. Richter, Ezzell, J., and Felix, D., "Single Laboratory Method Validation Report. Extractionof TCL/PPL (Target Compound List/Priority Pollutant List) BNAs and Pesticides using Accelerated Solvent Extraction (ASE) with Analytical Validation by GC/MS and GC/ECD";Document 116064.A, Dionex Corporation, June 16, 1994.2. B. Richter, Ezzell, J., and Felix, D., "Single Laboratory Method Validation Report. Extractionof TCL/PPL (Target Compound List/Priority Pollutant List) OPPs, Chlorinated Herbicides and PCBs using Accelerated Solvent Extraction (ASE)". Document 101124, Dionex Corporation, December 2, 1994).11.0SAFETYThe use of organic solvents, elevated temperatures, and high pressures in Method 3545 present potential safety concerns in the laboratory. Common sense laboratory practices can be employed to minimize these concerns. However, the following sections describe additional steps that should be taken.11.1Extraction cells in the oven are hot enough to burn unprotected skin. Allow the cells to cool before removing them from the oven or use appropriate protective equipment (e.g., insulated gloves or tongs), as recommended by the manufacturer.CD-ROM3545 - 7Revision 0December 199611.2During the gas purge step, some solvent vapors may exit through a vent port in the instrument. Follow the manufacturer's directions regarding connecting this port to a fume hood or other means to prevent release of solvent vapors to the laboratory atmosphere.11.3The instrument may contain flammable vapor sensors and should be operated with all covers in place and doors closed to ensure proper operation of the sensors. If so equipped, follow the manufacturer's directions regarding replacement of extraction cell seals when frequent vapor leaks are detected.CD-ROM3545 - 8Revision 0December 1996CD-ROM 3545 - 9Revision 0December 1996METHOD 3545PRESSURIZED FLUID EXTRACTION (PFE)。

EPA方法索引范文EPA方法索引是指美国环境保护署（Environmental Protection Agency）使用的一种方法或指南的集合。

这些方法和指南被广泛应用于环境监测、控制和评估等领域，以确保环境和公共健康的保护。

以下是一些常见的EPA方法索引。

1.环境监测方法-EPA方法200.7：用于痕量金属分析的集中器分析方法。

-EPA方法353.2：用于水中氨氮的连续流动分析方法。

-EPA方法8010：挥发性有机化合物（VOCs）在土壤、固体废物和水样中的分析方法。

2.大气排放测量方法-EPA方法1：测量排放源气流量的方法。

-EPA方法3：使用热式测速计测量气流速度的方法。

-EPA方法25A：测量总有机气态污染物（TO-9A）的方法。

3.水质监测方法-EPA方法200.8：通过电感耦合等离子体发射光谱法（ICP-OES）测量地下水和饮用水中痕量金属的方法。

-EPA方法160.2：测量水和废水中总悬浮颗粒物（TSS）的方法。

-EPA方法300.0：用于汞浓度分析的氢化物发生-冷蒸汽原子吸收光谱法的方法。

4.土壤和固体废物分析方法-EPA方法3050B：提取土壤和固体废物中的金属的方法。

-EPA方法3540C：挥发性有机物在土壤、底泥和固体样品中的提取方法。

-EPA方法8260B：环境样品中挥发性有机物（VOCs）的气相色谱/质谱（GC/MS）分析法。

5.生物监测方法-EPA方法1605：用于大肠杆菌和菌落总数的微生物分析方法。

-EPA方法821-R-02-012：基于鱼类激素和特征蛋白的鱼类暴露评估方法。

-EPA方法821-R-02-013：用于粪臭强度测量的无尘试纸法。

需要注意的是，这只是EPA方法索引中的一小部分，并且每个方法都有详细的操作规程和分析步骤。

研究人员和环境监测单位可以根据需要，选择合适的方法来进行各种环境样品的分析和监测工作，以确保结果的准确性和可比性。

METHOD 3540CSOXHLET EXTRACTION1.0SCOPE AND APPLICATION1.1Method 3540 is a procedure for extracting nonvolatile and semivolatile organic compounds from solids such as soils, sludges, and wastes. The Soxhlet extraction process ensures intimate contact of the sample matrix with the extraction solvent.1.2This method is applicable to the isolation and concentration of water-insoluble and slightly water soluble organics in preparation for a variety of chromatographic procedures.1.3This method is restricted to use by or under the supervision of trained analysts. Each analyst must demonstrate the ability to generate acceptable results with this method.2.0SUMMARY OF METHOD2.1The solid sample is mixed with anhydrous sodium sulfate, placed in an extraction thimble or between two plugs of glass wool, and extracted using an appropriate solvent in a Soxhlet extractor.2.2The extract is then dried, concentrated (if necessary), and, as necessary, exchanged intoa solvent compatible with the cleanup or determinative step being employed.3.0INTERFERENCESRefer to Method 3500.4.0APPARATUS AND MATERIALS4.1Soxhlet extractor - 40 mm ID, with 500-mL round bottom flask.4.2Drying column - 20 mm ID Pyrex® chromatographic column with Pyrex® glass wool at bottom.NOTE:Fritted glass discs are difficult to decontaminate after highly contaminated extracts have been passed through. Columns without frits may be purchased.Use a small pad of Pyrex® glass wool to retain the adsorbent. Prewash theglass wool pad with 50 mL of acetone followed by 50 mL of elution solvent priorto packing the column with adsorbent.4.3Kuderna-Danish (K-D) apparatus4.3.1Concentrator tube - 10-mL, graduated (Kontes K-570050-1025 or equivalent).A ground-glass stopper is used to prevent evaporation of extracts.CD-ROM3540C - 1Revision 3December 19964.3.2Evaporation flask - 500-mL (Kontes K-570001-500 or equivalent). Attach toconcentrator tube with springs, clamps, or equivalent.4.3.3Snyder column - Three-ball macro (Kontes K-503000-0121 or equivalent).4.3.4Snyder column - Two-ball micro (Kontes K-569001-0219 or equivalent).4.3.5Springs - 1/2 inch (Kontes K-662750 or equivalent).NOTE:The following glassware is recommended for the purpose of solvent recovery during the concentration procedures requiring the use of Kuderna-Danishevaporative concentrators. Incorporation of this apparatus may be requiredby State or local municipality regulations that govern air emissions of volatileorganics. EPA recommends the incorporation of this type of reclamationsystem as a method to implement an emissions reduction program. Solventrecovery is a means to conform with waste minimization and pollutionprevention initiatives.4.4Solvent vapor recovery system (Kontes K-545000-1006 or K-547300-0000, Ace Glass 6614-30, or equivalent).4.5Boiling chips - Solvent-extracted, approximately 10/40 mesh (silicon carbide or equivalent).4.6Water bath - Heated, with concentric ring cover, capable of temperature control (± 5E C). The bath should be used in a hood.4.7Vials - Glass, 2-mL capacity, with polytetrafluoroethylene (PTFE)-lined screw or crimp top.4.8Glass or paper thimble or glass wool - Contaminant-free.4.9Heating mantle - Rheostat controlled.4.10Disposable glass pasteur pipet and bulb.4.11Apparatus for determining percent dry weight.4.11.1Drying oven - capable of maintaining 105E C.4.11.2Desiccator.4.11.3Crucibles - Porcelain or disposable aluminum.4.12Apparatus for grinding4.13Analytical balance - capable of weighing to 0.0001 g.CD-ROM3540C - 2Revision 3December 1996CD-ROM 3540C - 3Revision 3December 19965.0REAGENTS5.1Reagent grade inorganic chemicals shall be used in all tests. Unless otherwise indicated,it is intended that all reagents shall conform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where such specifications are available. Other gradesmay be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit itsuse without lessening the accuracy of the determination.5.2Organic-free reagent water. All references to water in this method refer to organic-freereagent water, as defined in Chapter One.5.3Sodium sulfate (granular, anhydrous), Na SO . Purify by heating at 400E C for 4 hours24in a shallow tray, or by precleaning the sodium sulfate with methylene chloride. If the sodium sulfateis precleaned with methylene chloride, a method blank must be analyzed, demonstrating that thereis no interference from the sodium sulfate.5.4Extraction solvents - All solvents must be pesticide quality or equivalent.5.4.1Soil/sediment and aqueous sludge samples shall be extracted using either of thefollowing solvent systems:5.4.1.1Acetone/Hexane (1:1) (v/v), CH COCH /C H . 33614NOTE:This solvent system has lower disposal cost and lower toxicity.5.4.1.2Methylene chloride/Acetone (1:1 v/v), CH Cl /CH COCH .22335.4.2Other samples shall be extracted using the following:5.4.2.1Methylene chloride, CH Cl .225.4.2.2Toluene/Methanol (10:1) (v/v), C H CH /CH OH.65335.5Exchange solvents - All solvents must be pesticide quality or equivalent.5.5.1Hexane, C H .6145.5.22-Propanol, (CH )CHOH.325.5.3Cyclohexane, C H .6125.5.4Acetonitrile, CH CN.36.0SAMPLE COLLECTION, PRESERVATION, AND HANDLINGSee the introductory material to this chapter, Organic Analytes, Section 4.1.%dry weight 'g of dry sample g of sample×100CD-ROM 3540C - 4Revision 3December 19967.0PROCEDURE7.1Sample Handling7.1.1Sediment/soil samples - Decant and discard any water layer on a sedimentsample. Mix sample thoroughly, especially composited samples. Discard any foreign objectssuch as sticks, leaves, and rocks.7.1.2Waste samples - Samples consisting of multiple phases must be prepared by thephase separation method in Chapter Two before extraction. This extraction procedure is forsolids only.7.1.3Dry waste samples amenable to grinding - Grind or otherwise subdivide the wasteso that it either passes through a 1-mm sieve or can be extruded through a 1-mm hole.Introduce sufficient sample into the grinding apparatus to yield at least 10 g after grinding.7.1.4Gummy, fibrous, or oily materials not amenable to grinding should be cut,shredded, or otherwise reduced in size to allow mixing and maximum exposure of the samplesurfaces for the extraction. The addition of anhydrous sodium sulfate to the sample (1:1) maymake the mixture amenable to grinding.7.2Determination of percent dry weight - When sample results are to be calculated on a dryweight basis, a second portion of sample should be weighed at the same time as the portion usedfor analytical determination.WARNING:The drying oven should be contained in a hood or be vented. Significantlaboratory contamination may result from drying a heavily contaminated sample.Immediately after weighing the sample for extraction, weigh 5 - 10 g of the sample into a taredcrucible. Dry this aliquot overnight at 105E C. Allow to cool in a desiccator before weighing.Calculate the % dry weight as follows:This oven-dried aliquot is not used for the extraction and should be disposed of appropriatelyonce the dry weight has been determined.7.3Blend 10 g of the solid sample with 10 g of anhydrous sodium sulfate and place in anextraction thimble. The extraction thimble must drain freely for the duration of the extraction period.A glass wool plug above and below the sample in the Soxhlet extractor is an acceptable alternativefor the thimble.7.3.1Add 1.0 mL of the surrogate standard spiking solution onto the sample (seeMethod 3500 for details on the surrogate standard and matrix spiking solutions).7.3.2For the sample in each analytical batch selected for spiking, add 1.0 mL of thematrix spiking standard.7.3.3Consult Secs. 5.5 and 8.3 of Method 3500 for the appropriate choice of matrixspiking compounds and concentrations.7.4Place approximately 300 mL of the extraction solvent (Sec. 5.4) into a 500-mL round bottom flask containing one or two clean boiling chips. Attach the flask to the extractor and extract the sample for 16 - 24 hours at 4 - 6 cycles/hour.7.5Allow the extract to cool after the extraction is complete.7.6Assemble a Kuderna-Danish (K-D) concentrator (Sec. 4.3), if necessary, by attaching a 10-mL concentrator tube to a 500-mL evaporation flask.7.7Attach the solvent vapor recovery glassware (condenser and collection device) (Sec. 4.4) to the Snyder column of the K-D apparatus following manufacturer's instructions.7.8Dry the extract by passing it through a drying column containing about 10 cm of anhydrous sodium sulfate. Collect the dried extract in a K-D concentrator. Wash the extractor flask and sodium sulfate column with 100 to 125 mL of extraction solvent to complete the quantitative transfer.7.9Add one or two clean boiling chips to the flask and attach a three-ball Snyder column. Prewet the Snyder column by adding about 1 mL of methylene chloride to the top of the column. Place the K-D apparatus on a hot water bath (15 - 20E C above the boiling point of the solvent) so that the concentrator tube is partially immersed in the hot water and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the apparatus and the water temperature, as required, to complete the concentration in 10 - 20 minutes. At the proper rate of distillation the balls of the column will actively chatter, but the chambers will not flood. When the apparent volume of liquid reaches 1 - 2 mL, remove the K-D apparatus from the water bath and allow it to drain and cool for at least 10 minutes.7.10If a solvent exchange is required (as indicated in Table 1), momentarily remove the Snyder column, add approximately 50 mL of the exchange solvent and a new boiling chip, and reattach the Snyder column. Concentrate the extract as described in Sec. 7.9, raising the temperature of the water bath, if necessary, to maintain proper distillation. When the apparent volume again reaches 1 - 2 mL, remove the K-D apparatus from the water batch and allow it to drain and cool for at least 10 minutes.7.11 Remove the Snyder column and rinse the flask and its lower joints into the concentrator tube with 1 - 2 mL of methylene chloride or exchange solvent. If sulfur crystals are a problem, proceed to Method 3660 for cleanup. The extract may be further concentrated by using the techniques described in Sec. 7.12 or adjusted to 10.0 mL with the solvent last used.7.12If further concentration is indicated in Table 1, either micro Snyder column technique (Sec. 7.12.1) or nitrogen blowdown technique (Sec. 7.12.2) is used to adjust the extract to the final volume required.7.12.1Micro Snyder column technique7.12.1.1Add another one or two clean boiling chips to the concentrator tube andattach a two-ball micro Snyder column. Prewet the column by adding about 0.5 mL ofmethylene chloride or exchange solvent to the top of the column. Place the K-Dapparatus in a hot water bath so that the concentrator tube is partially immersed in thehot water. Adjust the vertical position of the apparatus and the water temperature, asrequired, to complete the concentration in 5 - 10 minutes. At the proper rate of distillationthe balls of the column will actively chatter, but the chambers will not flood.CD-ROM3540C - 5Revision 3December 19967.12.1.2When the apparent volume of liquid reaches 0.5 mL, remove the K-Dapparatus from the water bath and allow it to drain and cool for at least 10 minutes.Remove the Snyder column and rinse the flask and its lower joints with about 0.2 mL ofsolvent and add to the concentrator tube. Adjust the final volume to 1.0 - 2.0 mL, asindicated in Table 1, with solvent.7.12.2Nitrogen blowdown technique7.12.2.1Place the concentrator tube in a warm water bath (approximately 35E C)and evaporate the solvent volume to the required level using a gentle stream of clean,dry nitrogen (filtered through a column of activated carbon).CAUTION:Do not use plasticized tubing between the carbon trap and thesample, since it may introduce contaminants.7.12.2.2The internal wall of the tube must be rinsed several times with theappropriate solvent during the operation. During evaporation, the solvent level in thetube must be positioned to prevent water from condensing into the sample (i.e., thesolvent level should be below the level of the water bath). Under normal operatingconditions, the extract should not be allowed to become dry.CAUTION:When the volume of solvent is reduced below 1 mL, semivolatileanalytes may be lost.7.13The extracts obtained may now be analyzed for the target analytes using the appropriate organic technique(s) (see Sec. 4.3 of this Chapter). If analysis of the extract will not be performed immediately, stopper the concentrator tube and refrigerate. If the extract will be stored longer than 2 days, it should be transferred to a vial with a PTFE-lined screw cap or crimp top, and labeled appropriately.8.0QUALITY CONTROL8.1Any reagent blanks, matrix spikes, or replicate samples should be subjected to exactly the same analytical procedures as those used on actual samples.8.2Refer to Chapter One for specific quality control procedures and Method 3500 for extraction and sample preparation procedures.9.0METHOD PERFORMANCERefer to the determinative methods for performance data.10.0REFERENCESNone.CD-ROM3540C - 6Revision 3December 1996CD-ROM 3540C - 8Revision 3December 1996METHOD 3540CSOXHLET EXTRACTION。

美国环保局EPA试验方法美国环保局EPA试验方法9045dSoilandWastepHMETHOD 9045DSOIL AND WASTE pH1.0SCOPE AND APPLICATION1.1This method is an electrometric procedure for measuring pH in soils and waste samples. Wastes may be solids, sludges, or non-aqueous liquids. If water is present, it must constitute less than 20% of the total volume of the sample.2.0SUMMARY OF METHOD2.1The sample is mixed with reagent water, and the pH of the resulting aqueous solution is measured.3.0INTERFERENCES3.1Samples with very low or very high pH may give incorrect readings on the meter. For samples with a true pH of >10, the measured pH may be incorrectly low. This error can be minimized by using a low-sodium-error electrode. Strong acid solutions, with a true pH of <1, may give incorrectly high pH measurements.3.2Temperature fluctuations will cause measurement errors.3.3Errors will occur when the electrodes become coated. If an electrode becomes coated with an oily material that will not rinse free, the electrode can (1) be cleaned with an ultrasonic bath, or (2) be washed with detergent, rinsed several times with water, placed in 1:10 HCl so that the lower third of the electrode is submerged, and then thoroughly rinsed with water, or (3) be cleaned per the manufacturer's instructions.4.0APPARATUS AND MATERIALS4.1pH meter with means for temperature compensation.4.2Glass electrode.4.3Reference electrode -- A silver-silver chloride or other reference electrode of constant potential may be used.NOTE:Combination electrodes incorporating both measuring and referenced functions are convenient to use and are available with solid, gel-type filling materials that require minimal maintenance.4.4Beaker -- 50-mL.4.5Thermometer and/or temperature sensor for automatic compensation.4.6Analytical balance -- capable of weighing 0.1 g.5.0REAGENTS5.1Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.5.2Reagent water. All references to water in this method refer to reagent water, as defined in Chapter One.5.3Primary standard buffer salts are available from the National Institute of Standards and Technology (NIST) and should be used in situations where extreme accuracy is necessary. Preparation of reference solutions from these salts requires some special precautions and handling, such as low-conductivity dilution water, drying ovens, and carbon-dioxide-free purge gas. These solutions should be replaced at least once each month.5.4Secondary standard buffers may be prepared from NIST salts or purchased as solutions from commercial vendors. Thesecommercially available solutions, which have been validated by comparison with NIST standards, are recommended for routine use.6.0SAMPLE PRESERVATION AND HANDLINGSamples should be analyzed as soon as possible.7.0PROCEDURE7.1Calibration7.1.1Because of the wide variety of pH meters and accessories, detailedoperating procedures cannot be incorporated into this method. Each analyst must beacquainted with the operation of each system and familiar with all instrument functions.Special attention to care of the electrodes is recommended.7.1.2Each instrument/electrode system must be calibrated ata minimum oftwo points that bracket the expected pH of the samples and are approximately three pH units or more apart. Repeat adjustments on successive portions of the two buffer solutions until readings are within 0.05 pH units of the buffer solution value. If anaccurate pH reading based on the conventional pH scale [0 to 14 at 25 E C] is required, the analyst should control sample temperature at 25 ± 1 E C when sample pH approaches the alkaline end of the scale (e.g., a pH of 11 or above).7.2Sample preparation and pH measurement of soils:7.2.1To 20 g of soil in a 50-mL beaker, add 20 mL of reagent water, cover, andcontinuously stir the suspension for 5 min. Additional dilutions are allowed if working with hygroscopic soils and saltsor other problematic matrices.7.2.2Let the soil suspension stand for about 1 hr to allow most of thesuspended clay to settle out from the suspension or filter or centrifuge off the aqueousphase for pH measurement.7.2.3Adjust the electrodes in the clamps of the electrode holder so that, uponlowering the electrodes into the beaker, the glass electrode will be immersed just deep enough into the clear supernatant solution to establish a good electrical contact through the ground-glass joint or the fiber-capillary hole. Insert the electrodes into the samplesolution in this manner. For combination electrodes, immerse just below the suspension.7.2.4If the sample temperature differs by more than 2 E C from the buffersolution, the measured pH values must be corrected.7.2.5Report the results as "soil pH measured in water at E C" where " E C" isthe temperature at which the test was conducted.7.3Sample preparation and pH measurement of waste materials7.3.1To 20 g of waste sample in a 50-mL beaker, add 20 mL of reagent water,cover, and continuously stir the suspension for 5 min. Additional dilutions are allowed if working with hygroscopic wastes and salts or other problematic matrices.7.3.2Let the waste suspension stand for about 15 min to allow most of thesuspended waste to settle out from the suspension or filter or centrifuge off aqueousphase for pH measurement.NOTE:If the waste is hygroscopic and absorbs all the reagent water, begin theexperiment again using 20 g of waste and 40 mL of reagent water.NOTE:If the supernatant is multiphasic, decant the oily phase and measure the pH of the aqueous phase. The electrode may need to be cleaned (Step 3.3) if itbecomes coated with an oily material.7.3.3Adjust the electrodes in the clamps of the electrode holder so that, uponlowering the electrodes into the beaker, the glass electrode will be immersed just deep enough into the clear supernatant to establish good electrical contact through the ground-glass joint or the fiber-capillary hole. Insert the electrode into the sample solution in this manner. For combination electrodes, immerse just below the suspension.7.3.4If the sample temperature differs by more than 2 E C from the buffersolution, the measured pH values must be corrected.7.3.5Report the results as "waste pH measured in water at E C" where " E C"is the temperature at which the test was conducted.8.0QUALITY CONTROL8.1Refer to Chapter One for the appropriate QC protocols.8.2Electrodes must be thoroughly rinsed between samples.9.0METHOD PERFORMANCE9.1No data provided.10.0REFERENCES1.Black, Charles Allen; Methods of Soil Analysis; American Society of Agronomy:Madison, WI, 1973.2.National Bureau of Standards, Standard Reference Material Catalog, 1986-87, SpecialPublication 260.METHOD 9045D SOIL AND WASTE pH。

美国EPA快速评价体系
美国EPA快速评价体系：EPA是美国环境保护署(U.SEnvironmentalProtectionAgency)的英文缩写。

美国EPA快速评价体系的主要任务是保护人类健康和自然环境。

EPA总部设在华盛顿, 有 10 个地方办公室和几十个实验室。

在全美国有18000 名雇员。

他们半数以上是工程师 , 科学家和政策分析家。

负责对很多环境项目设立国家标准 , 监控强制性标准的执行和符合情况。

EPA 联合州和地方政府颁发一系列商业以及工业许可证。

EPA认证美国环保总署EPA的主要目的是保护人民健康、保护生态环境--空气、水和土地这些我们赖以生存的环境。

在成立之后的30多年，EPA一直在为给全美人民创造一个整洁的健康环境而努力。

如果符合EPA要求，则EPA会颁发符合证书。

EPA方法索引和相关标准品EPA 是美国国家环境保护局(U.S Environmental Protection Agency) 的英文缩写。

它的主要任务是保护人类健康和自然环境。

EPA 制定了一系列标准分析方法用于环境监测领域。

主要包括：EPA T01～T14 系列标准分析方法——空气中有毒有机物分析方法EPA IP1～IP10 系列标准分析方法——室内空气污染物的分析测定方法EPA 200 系列标准分析方法———金属的分析方法EPA 500 系列标准分析方法——饮用水中有机物的分析方法EPA 600 系列标准分析方法——城市和工业废水中有机化合物的分析方法SW -846 系列标准分析方法——固体废弃物试验分析评价手册1300 系列是毒性试验方法3000 系列是金属元素的提取方法3500 系列是半(非) 挥发性有机物的提取方法3600 系列是净化、分离方法5000 系列是挥发性有机物的提取方法6000 系列是测定金属的新方法7000 系列是原子吸收法测定金属元素8000 系列是有机物分析方法9000 系列是常规项目分析方法其中，500系列，600系列和8000系列是环境种有机物分析最常用的方法。

EPA 600系列方法是美国为贯彻“净水法”(CW A) 、“全国水体污染物排放消除制度”(NPDES) 和“许可证制度”,严格控制点源排放,保护地表水,使其免受城市和工业废水中有机物的污染而制定的。

EPA 500 系列方法是为执行“安全饮用水法”(SDW A) 和“国家一级饮用水法案”(National Primary Drinking Water Regulations) ,确保饮用水及饮用水源的质量而制订的。

EPA 500 系列是针对比较洁净的水样(饮用水、地下水、地表水) 开发的,有些方法仅用试剂水和饮用水验证过SW-846 系列集中贯彻了“资源保护回收法”和“陆地处置限制法规”的精神,包含了固体废弃物采样和分析试验的全部方法, 是在EPA200 ～EPA 600 系列的基础上发展起来的。