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美国VOCs监测的标准规范文章导读美国EPA关于VOCs分析方法有3种：环境空气、室内空气和固定污染源。
而EPA也颁布了一系列仪器性能要求标准。
本文从上述两个方面介绍了美国关于VOCs 监测的标准规范。
EPA在40 CFR PART 60 中配套的固定源废气VOCs的监测方法标准见下表。
第一大类：通过GC将混合气体中主要有机物分离后，用FID、ECD、PID、ELCD 或其它检测器进行各组分定性、定量检测。
这是我们国内常用的GC-FID在线系统，PID也运营较多，因价格差异和效果差异巨大，一般监管单位目前在固定源上的VOCs在线监测要求均为GC-FID原理。
第二大类：总气态有机物（TOC）浓度的测定火焰离子化分析法（FIA），由加热采样管、管路、玻璃纤维过滤器和FIA 分析仪构成现场在线分析，直接连续测定TOC 浓度。
此法在国内固定源VOCs监测运营不多。
第三大类：总气态有机物(TOC)浓度的测定非分散红外分析法（NDIR）。
直接接口取样系统现场在线分析。
主要用于含烷烃的总气态有机物浓度的测定。
NDIR主要为日本技术，国内有代理商。
第四大类：抽取式傅立叶红外法（FTIR）测定气态有机、无机化合物(HAPs)。
明确水蒸气和二氧化碳是红外波段最普遍的干扰。
主要运用在厂界监测，溯源，及目前国内发展的所谓“空间立体监测”。
值得一直提的是，EPA颁布了一系列仪器性能要求标准（PerformanceSpecification, PS），其中PS8是污染源VOCs在线监测仪器的总纲，PS8A是用FID原理监测总烃仪器的技术要求，PS9针对气相色谱法监测VOCs的仪器，PS15针对傅立叶红外法监测VOCs的仪器，见下表。
素材来源：VOCs减排工作站编辑：VOCs前沿。
Internet9071B - 1Revision 2April 1998METHOD 9071Bn-HEXANE EXTRACTABLE MATERIAL (HEM) FOR SLUDGE, SEDIMENT, AND SOLID SAMPLES 1.0SCOPE AND APPLICATION1.1Method 9071 may be used to quantify low concentrations of oil and grease in soil,sediments, sludges, and other solid materials amenable to chemical drying and solvent extraction with n-hexane. “Oil and grease” is a conventional pollutant under 40 CFR 401.16 and generally refers to substances, including biological lipids and mineral hydrocarbons, that have similar physical characteristics and common solubility in an organic extracting solvent. As such, oil and grease is an operationally defined parameter, and the results will depend entirely on the extracting solvent and method of extraction. Method 9071 employs n-hexane as the extraction solvent with Soxhlet extraction and the results of this method are appropriately termed “n-hexane extractable material (HEM).” Section 1.2 lists the type of materials that may be extracted by this method. In the context of this method, “HEM” is used throughout this method and for operational purposes, may be considered synonymous with “oil and grease” within the limitations discussed below.1.2Specifically, Method 9071 is suitable for extracting relatively non-volatile hydrocarbons,vegetable oils, animal fats, waxes, soaps, greases, biological lipids, and related materials. 1.3Method 9071 is not recommended for measuring materials that volatilize at temperatures below 85E C. Petroleum fuels from gasoline through #2 fuel oil may be partially lost during the solvent removal process.1.4 Some crude oils and heavy fuel oils may contain materials that are not soluble in n-hexane, and recovery of these materials may be low.2.0SUMMARY OF METHOD2.1 A representative portion of wet (as received) waste is acidified with concentrated HCl and chemically dried with magnesium sulfate or sodium sulfate. Magnesium sulfate monohydrate is used to dry acidified sludges as it will combine with 75% of its own weight in water in forming MgSO C 7H O. Anhydrous sodium sulfate is used to dry soil and sediment samples. 4 2 2.2After drying, the HEM is extracted with n-hexane using a Soxhlet apparatus. The n-hexane extract is then distilled from the extract and the HEM is desiccated and weighed. 2.3 When necessary, a separate sample portion is evaluated for percent solids, and the dry weight fraction may be used to calculate the dry-weight HEM concentration of the soil, sediment,or waste.3.0DEFINITIONS3.1n-Hexane extractable material (HEM, oil and grease): Material that is extracted from a sample using n-hexane and determined by this method. This material includes relatively non-volatile hydrocarbons, vegetable oils, animal fats, waxes, soaps, greases, and related matter.3.2Refer to Chapter One for additional definitions.4.0INTERFERENCES4.1 This method is entirely empirical, and duplicate results having a high degree of precision can be obtained only by strict adherence to all details. The rate of cycling and time of extraction in the Soxhlet apparatus must be consistent and length of time required for drying and cooling extracted materials must be the same in order to generate consistent results. It is important that the procedures be performed as directed due to the varying solubilities of the different greases and heavy mineral oils.4.2Solvents, reagents, glassware, and other sample-processing hardware may yield artifacts that could affect the results. All solvents and reagents used in the analysis should be demonstrated to be free from interferences by processing a method blank with each analytical batch. Specific selection of reagents, solvent washes, or purification of solvents may be required. Use of plastic measuring devices, and/or plastic tubing attachments must be avoided.4.3Glassware should be cleaned by washing with hot tap water with detergent, rinsing with tap water and reagent water, and rinsing with solvent. Glassware may also be baked at 200-250E C for 1 hour. Boiling flasks that are used to contain the extracted residues may be dried in an oven at 105-115E C and stored in a desiccator until used. Depending on the project DQOs, strict adherence to the washing and handling procedures cited above may not be necessary as long as the laboratory can demonstrate that alternative cleaning procedures yield acceptable method performance and meet method blank acceptance criteria.4.4 A gradual increase in weight may result due to the absorption of oxygen; a gradual loss of weight may result due to volatilization. Extracted residues should be maintained in a desiccator during cooling and prior to weighing. Extracted residues should be weighed as soon as possible after cooling.4.5The presence of non-oily extractable substance such as sulfur compounds, organic dyes, and chlorophyll, may result in a positive bias. For the purpose of this method, all materials extracted and retained during this procedure are defined as HEM.5.0SAFETY5.1The toxicity or carcinogenicity of each reagent used in this method has not been precisely determined; however, each chemical should be treated as a potential health hazard. Exposure to these chemicals should be reduced to the lowest possible level. It is suggested that the laboratory perform personal hygiene monitoring of each analyst that uses this method. This monitoring should be performed using Occupational Safety and Health Administration (OSHA) or National Institute of Occupational Safety and Health (NIOSH) approved personal hygiene monitoring methods. Results of this monitoring should be made available to the analyst.5.2n-Hexane has been shown to have increased neurotoxic effects over other hexanes and some other solvents. OSHA has proposed a time-weighted average (TWA) of 50 parts-per-million (ppm); NIOSH concurs that an 8-hour TWA/permissible exposure limit (PEL) of 50 ppm is appropriate for n-hexane; and the American Conference of Governmental Industrial Hygienists (ACGIH) has published a threshold limit value (TLV) of 50 ppm for n-hexane. Inhalation of n-hexane should be minimized by performing all operations with n-hexane in a explosion-proof hood or well-ventilated area.Internet9071B - 2Revision 2April 19985.3n-Hexane has a flash point of -23E C (-9E F), has explosive limits in air in the range of 1 to 7 percent, and poses a serious fire risk when heated or exposed to flame. n-Hexane can react vigorously with oxidizing materials. The laboratory should include procedures in its operations that address the safe handling of n-hexane.5.4Unknown samples may contain high concentrations of volatile toxic compounds. Sample containers should be opened in a hood and handled with gloves to prevent exposure.5.5This 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 specified 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 SUPPLIES6.1Soxhlet extraction apparatus.6.2Heating mantle - explosion-proof, with temperature control.6.3Boiling flask - 125-mL or appropriate size.6.4Analytical balance - capable of weighing 0.1 mg.6.5Vacuum pump, or other vacuum source.6.6Paper extraction thimble for Soxhlet apparatus.6.7Glass wool or small glass beads to fill thimble.6.8Grease-free, non-absorbent cotton - To remove possible interferences, each batch of cotton should be washed with n-hexane. Solvent washing may not be necessary if the laboratory can demonstrate that the unwashed cotton does not affect the performance of the method or that the concentration of HEM in the sample is so high that low contaminant concentration is insignificant.6.9Beakers - 100- 150-mL.6.10pH paper.6.11Porcelain mortar and pestle.6.12Extraction flask - 150-mL or appropriate size.6.13Waterbath or steam bath-explosion-proof - capable of maintaining a temperature of at least 85E C.6.14Distilling apparatus - For removing n-hexane from extract.6.14.1Distilling head-Claisen (VWR Scientific No 26339-005, or equivalent), includesClaisen-type connecting tube and condenser.Internet9071B - 3Revision 2April 1998Internet9071B - 4Revision 2April 19986.14.2Distillation adapter (used to attach distilling head and to the waste collectionflask for recovery of solvent).6.14.3Distillate collection flask (attached to the distilling adaptor for collection of thedistilled solvent).6.14.4Ice bath or recirculating chiller (to aid in the condensation and collection ofthe distilled solvent).6.15Desiccator - Cabinet or jar type, capable of holding boiling flasks during cooling and storage.6.16Tongs - for handling the boiling flasks.6.17Glass fiber filter paper - Whatman No. 40 or equivalent.6.18Boiling chips - Silicon carbide or fluoropolymer.7.0REAGENTS7.1Reagent 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.7.2Reagent water. All references to water in this method refer to reagent water, as defined in Chapter One.7.3Concentrated hydrochloric acid (HCl).7.4 Magnesium sulfate monohydrate. Prepare MgSO C H O by spreading a thin layer in 4 2a dish and drying in an oven at 150E C overnight. Store in a tightly sealed glass container until used.7.5Sodium sulfate, granular, anhydrous (Na SO ). Purify by heating at 400E C for 4 hours 24in a shallow tray, or by precleaning the sodium sulfate with methylene chloride. If the sodium sulfate is precleaned with methylene chloride, a method blank must be analyzed, demonstrating that there is no interference from the sodium sulfate. Store in a tightly sealed glass container until used.7.6n-Hexane. Purity of 85%, 99.0% minimum saturated C isomers, residue less than 16mg/L. Boiling point, 69E C.7.7Hexadecane(CH (CH )CH )/stearic acid (CH (CH )COOH). 1:1 spiking solution.32143 3216Prepare in acetone at a concentration of 2 mg/mL each.Weigh 200 ± 2 mg of stearic acid and 200 ± 2 mg hexadecane into a 100 mL volumetric flask and fill to the mark with acetone. The total concentration of this stock is 4000 mg/L (ppm) HEM. This standard may be used for spiking samples and preparing laboratory control samples. Store in a glass container with a fluoropolymer-lined cap at room temperature. Shield from light.Note:The spiking solution may require warming for complete dissolution of stearic acid.8.0SAMPLE COLLECTION, PRESERVATION, AND STORAGE8.1 A minimum of 100 grams of sample should be collected using a metal spatula, spoon, or equivalent device. Samples should be collected into a pre-cleaned wide-mouth glass container fitted with a TFE-lined screw cap.8.2 When practical (i.e., when the sample matrix allows the complete mixing of sample and acid such as with a pourable sludge or sediment), the sample should be preserved to a pH < 2 by adding 1 mL of concentrated HCl per 100 gram of sample and cooled to 4 ± 2 E C. If acidification is not practical (as with a dry soil), the addition of the HCl is not required and the sample should be cooled to 4 ± 2 E C. The laboratory must be notified so that the sample can be acidified prior to analysis.8.3 A holding time has not been established for HEM in solids, but it is recommended that the sample be analyzed as soon as possible.9.0QUALITY CONTROL9.1Each laboratory that uses this method is required to operate a formal quality control program. The minimum requirements of this program consist of an initial demonstration of laboratory capability and the analysis of spiked samples as a continuing check on performance. The laboratory is required to maintain performance records to define the quality of data that is generated.9.2 Employ a minimum of one method blank per analytical batch or twenty samples, whichever is more frequent, to verify that all reagents, solvents, and equipment are contamination free. Prepare the method blank from 5 g of inert matrix such as pre-cleaned sand or similar material, and carry it through the analytical process.9.3 Run one matrix duplicate and matrix spike sample every twenty samples or analytical batch, whichever is more frequent. Matrix duplicates and spikes are brought through the whole sample preparation and analytical process.9.4The performance of the method should be evaluated by the use of a Laboratory Control Sample (LCS). The LCS is prepared by spiking an inert matrix (as pre-cleaned sand or similar material) with an appropriate volume of spiking solution (Sec. 7.7) and carrying it through the analytical process.10.0CALIBRATION AND STANDARDIZATION10.1Calibrate the analytical balance at 2 mg and 1000 mg using class “S” weights.10.2Calibration shall be within ± 10% (i.e., ± 0.2 mg) at 2 mg and ± 0.5 % (i.e., ± 5 mg) at 1000 mg. If values are not within these limits, recalibrate the balance.Internet9071B - 5Revision 2April 1998dry weight fraction 'g of dry sample g of sampleInternet 9071B - 6Revision 2April 199811.0PROCEDURE11.1Determination of Sample Dry Weight Fraction11.1.1When it is necessary to report the HEM on a dry weight basis, determine thedry weight fraction using a separate aliquot of sample, as discussed below. The aliquot used for this determination cannot be used to evaluate HEM.11.1.2Weigh 5-10 gram (± 0.01 gram) of the sample into pre-weighed crucible.Determine the weight of the wet sample by subtracting the weight of the crucible.11.1.3Place the crucible with the wet sample in an oven overnight at 105E C.Remove crucible from oven and place in a desiccator to cool. Weigh. Determine dry weight of sample by subtracting the weight of the crucible. Determine the dry weight fraction of the sample as follows:NOTE:The drying oven should be contained in a hood or vented. Significant laboratory contamination may result from a heavily contaminated hazardous waste sample.11.2Sample Preparation 11.2.1Sludge/Waste Samples 11.2.1.1Weigh out 20 ± 0.5 grams of wet sample into a 150-mL beaker.11.2.1.2If the sample has not been acidified, acidify to a pH # 2 withapproximately 0.3 mL concentrated HCl.11.2.1.3Add 25 grams Mg SO C H O (Sec. 7.4) and stir to a smooth24 2paste.11.2.1.4 Spread paste on sides of beaker to facilitate evaporation. Letstand about 15-30 min or until material is solidified.11.2.1.5 Remove solids and grind to fine powder in a mortar.11.2.1.6Add the powder to the paper extraction thimble.11.2.1.7 Wipe beaker and mortar with pieces of filter paper moistened withn-hexane and add to thimble.11.2.1.8Fill thimble with glass wool (or glass beads).11.2.2Sediment/Soil Samples11.2.2.1Decant and discard any water layer on a sediment sample. Mixsample thoroughly, especially composited samples. Discard any foreign objects suchas sticks, leaves, and rocks.11.2.2.2Blend 10 grams of the sample with 10 grams of anhydrous sodiumsulfate (Sec. 7.5) as described in Section 11.2.1. Transfer homogenized paste to anextraction thimble and cover with glass wool or glass beads. The extraction thimblemust drain freely for the duration of the extraction period.11.3Extraction11.3.1 Set-up the Soxhlet apparatus containing the extraction thimble and sampleand attach a 125-mL boiling flask containing 90 mL of n-hexane. Add boiling chips. Adjust the heating control on the heating mantle so that a cycling rate of 20 cycles/h is obtained. Extract for a period of 4 hrs.11.3.2Tare a clean 250-mL or appropriate sized boiling flask as follows:11.3.2.1Dry the flask in an oven at 105-115E C for a minimum of 2 h.11.3.2.2Remove from the oven and immediately transfer to a desiccatorto cool at room temperature.11.3.2.3When cool, remove from the desiccator with tongs and weighimmediately on a calibrated balance.11.3.3At the end of the 4 h extraction period, filter the extract through grease-freecotton, into the pre-weighed boiling flask (Sec. 11.3.2). Use gloves to avoid adding fingerprints to the flask.11.3.4Rinse flask and cotton with n-hexane and add to the 250-mL boiling flask.NOTE:If the extract is clear and no suspended particles are present, the filtration step may be omitted.11.3.5Connect the boiling flask to the distilling head apparatus and distill the solventby immersing the lower half of the flask in a water bath or a steam bath. A heating mantle may also be used. Adjust the temperature of the heating device to complete the distillation in less than 30 minutes. Collect the solvent for reuse or appropriate disposal.11.3.6When the distillation is complete, remove the distilling head. Immediatelyremove the flask from the heat source and wipe the outside to remove excess moisture and fingerprints. To remove solvent vapor, sweep out the flask for 15 sec with air by inserting a glass tube that is connected to a vacuum source.11.3.7Cool the boiling flask in a desiccator for 30 min and weigh. Determine thegain in weight of the boiling flask by subtracting the weight of the boiling flask (Sec. 11.3.2) from the final boiling flask weight.Internet9071B - 7Revision 2April 1998HEM (mg/kg wet weight)'gain in weight of flask(mg)X 1000weight of wet solid(g)Internet9071B - 8Revision 2April 199812.0DATA ANALYSIS AND CALCULATIONSCalculate the concentration of HEM in the sample as follows:NOTE:If it is necessary to report the results on a dry weight basis, divide the result obtained above by the dry weight fraction calculated in Sec. 11.1.3. Report the results as mg/kg HEM dry weight. If it is necessary to report the results as a percentage of the wet or dry weight, divide the wet-weight concentration or dry weight concentration by 10,000 and report the result as % HEM wet or dry weight.13.0METHOD PERFORMANCEIn a preliminary study designed to find a suitable replacement for Freon-113, three EPA contract laboratories evaluated a total of 28 solid samples derived from various industrial and commercial processes for oil and grease. This study evaluated a total of six solvents, including n-hexane, to determine which of the alternative solvents produced results most closely with that of Freon-113. In this study, each waste was Soxhlet-extracted in triplicate using Freon-113 and each of the alternative solvents. Based on the overall results, n-hexane was judged to be the best alternative solvent. The data provided in Table 1 compare the results for Freon-113 and n-hexane for each waste. For a complete discussion of this study, refer to reference 1 in Section 16.0.14.0POLLUTION PREVENTION14.1Pollution prevention encompasses any technique that reduces or eliminates the quantity and/or toxicity of waste at the point of generation. Numerous opportunities for pollution prevention exist in laboratory operation. The EPA has established a preferred hierarchy of environmental management techniques that places pollution prevention as the management option of first choice.Whenever feasible, laboratory personnel should use pollution prevention techniques to address their waste generation. When wastes cannot be feasibly reduced at the source, the Agency recommends recycling as the next best option.14.2For information about pollution prevention that may be applicable to laboratories and research institutions consult Less is Better: Laboratory Chemical management for Waste Reduction available from the American Chemical Society’s Department of Government Relations and Science Policy, 1155 16th St., N.W. Washington, D.C. 20036, (202) 872-4477.15.0WASTE MANAGEMENTThe Environmental Protection Agency requires that laboratory waste management practices be conducted consistent with all applicable Federal, state and local rules and regulations. The Agency urges laboratories to protect the air, water, and land by minimizing and controlling all releases from hoods and bench operations, complying with the letter and spirit of any sewerdischarge permits and regulations, and by complying with all solid and hazardous waste regulations, particularly the hazardous waste identification rules and land disposal restrictions. For further information on waste management, consult The Waste Management Manual for Laboratory Personnel available from the American Chemical Society at the address listed in Sec. 14.2.16.0REFERENCES1.Preliminary Report of EPA Efforts to Replace Freon for the Determination of Oil and Grease,United States Environmental Protection Agency, Office of Water, EPA-821-93-009. June 1993.2.Method 1664, Revision A: n-Hexane Extractable Material (HEM; Oil and Grease) and Silica GelTreated N-Hexane Extractable Material (SGT-HEM) by Extraction and Gravimetry.17.0TABLES, DIAGRAMS, FLOWCHARTS, AND VALIDATION DATAThe pages to follow contain Table 1, and a flow diagram of the method procedure.Internet9071B - 9Revision 2April 1998TABLE 1SOXHLET EXTRACTION OF SOLIDS USING FREON-113 AND N-HEXANEAll concentrations in mg/kgFacility/Waste Stream Solvent:Rep Rep Rep Mean Standard Process Freon No. 1 No. 2No. 3Concen-DeviationHexane trationPaper Mill Dewatered Freon110005300790080002762 Sludge Hexane660024001100066004203POTW Sewage Freon980008100081000870009940 Sludge Hexane11000086000800009100013281Leather Dewatered Freon11000120001200012000732 Tannery Sludge Hexane210001500019000180003201 POTW Digested Freon13000097000660009800033028 Sludge Hexane5400076000480005900014516Petroleum API Separator Freon32000035000025000031000053257 Refinery Sludge Hexane24000032000024000027000043822 Industrial DAF Freon31000031000024000029000041717 Laundry Sludge Hexane29000036000018000028000090819Fish Oil Oily Freon8900001000000770000890000131249 Plant Sludge Hexane44000053000046000048000046318 Coke Plant Waste Freon8300800018000110005505 Activated Hexane140001900015000160002732SludgeWood Solid Freon1500001400001400001400003512 Preserving Waste Hexane1400001300001300001300006557 PlantDrilling Fluid Used drilling Freon1300160013001400157 Supplier mud Hexane1300120016001400201 Contam.Kerosene Freon2000140019001700352 Soils Contaminated Hexane2500320026002800410 SoilPoultry Plant Waste Freon3800011000400003000016263 Activated Hexane590011000460002100021795SludgeRolling Mill Dewatered Freon110001400017000140002884 Scale Hexane14000140001600015000983 Mayonnaise Oily Sludge Freon88000085000078000084000050521 Plant Hexane590000780000520000630000132020Seafood Waste Sludge Freon6400053000580007526 Plant Hexane340003100027000310003867 Internet9071B - 10Revision 2April 1998TABLE 1(CONTINUED)Facility/Waste Stream Solvent:Rep Rep Rep Mean Standard Process Freon No. 1 No. 2No. 3Concen-DeviationHexane trationSeafood Oily Sludge Freon40000041000043000041000016371 Plant Hexane4000003900003900004000007095Poultry DAF Sludge Freon67000060000057000061000049549 Plant Hexane5300005300005300005300002449Railroad Oily Sludge Freon87000092000087000089000027906 Yard Hexane8500008400008300008400006884 Can Filter Cake Freon62000620006000061000976 Manufact Hexane690006400066000660002615 PlantSoup Plant DAF Sludge Freon60000059000061000060000010066Hexane58000052000060000057000040361Oily Water Oily Sludge Freon760007500070000740003215 Treatment Hexane7700060000790007200010713 PlantCan Oily Sludge Freon940008800094000920003291 Manufact Hexane800009000083000850004992 PlantCan Filter Cake Freon2900002900003000002900006217 Manufact Hexane2900002900002900002900002029 PlantDrum Oily Sludge Freon120000011000001200000120000057735 Handling Hexane9900001000000980000100000027319 FacilityPolymer Dewatered Freon13000120008200110002524 Plant Sludge Hexane84006900910081001122 Restaurant Vegetable Oil Freon76000061000078000072000092060 Waste Hexane1100000980000980000100000080064Leather Waste Sludge Freon18000022000019000019000022140 Tannery Hexane24000027000021000024000031177 Source: Reference 1Internet9071B - 11Revision 2April 1998METHOD 9071Bn-HEXANE EXTRACTABLE MATERIAL (HEM) FOR SLUDGE, SEDIMENT, AND SOLID SAMPLESInternet9071B - 12Revision 2April 1998METHOD 9071Bn-HEXANE EXTRACTABLE MATERIAL (HEM) FOR SLUDGE, SEDIMENT, AND SOLID SAMPLES(Continued)Internet9071B - 13Revision 2April 1998。
EPA方法索引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。
气相色谱法科技名词定义中文名称：气相色谱法英文名称：gas chromatography定义：用气体作为流动相的色谱法。
用气体作为移动相的色谱法。
根据所用固定相的不同可分为两类：固定相是固体的，称为气固色谱法；固定相是液体的则称为气液色谱法。
目录简介拼音英文参考定义对仪器的一般要求原理发展简史仪器装置和操作气流系统分离系统检测系统数据处理系统温度控制系统及其他辅助部件流动相固定相操作温度样品预处理分类内标准法绝对标准曲线法峰面积百分率法定性和定量分析综述定性分析定量分析应用优缺点优点缺点展望gas phase chromatography定义：气相色谱法（gas chromatography 简称GC）是色谱法的一种。
色谱法中有两个相，一个相是流动气相色谱图相，另一个相是固定相。
如果用液体作流动相，就叫液相色谱，用气体作流动相，就叫气相色谱。
气相色谱法由于所用的固定相不同，可以分为两种，用固体吸附剂作固定相的叫气固色谱，用涂有固定液的担体作固定相的叫气液色谱。
按色谱分离原理来分，气相色谱法亦可分为吸附色谱和分配色谱两类，在气固色谱中，固定相为吸附剂，气固色谱属于吸附色谱，气液色谱属于分配色谱。
按色谱操作形式来分，气相色谱属于柱色谱，根据所使用的色谱柱粗细不同，可分为一般填充柱和毛细管柱两类。
一般填充柱是将固定相装在一根玻璃或金属的管中，管内径为2～6毫米。
毛细管柱则又可分为空心毛细管柱和填充毛细管柱两种。
空心毛细管柱是将固定液直接涂在内径只有0.1～0.5毫米的玻璃或金属毛细管的内壁上，填充毛细管柱是近几年才发展起来的，它是将某些多孔性固体颗粒装入厚壁玻管中，然后加热拉制成毛细管，一般内径为0.25～0.5毫米。
在实际工作中，气相色谱法是以气液色谱为主。
对仪器的一般要求：所用的仪器为气相色谱仪。
除另有规定外，载气为氮气；色谱柱为填充柱或毛细管柱，填充柱的材质为不锈钢或玻璃，载体用直径为0.25～0.18mm 、0.18～0.15mm或0.15～0.125mm经酸洗并硅烷化处理的硅藻土或高分子多孔小球；常用玻璃或弹性石英毛细管柱的内径为0.20或0.32mm。
气相色谱仪法规要求气相色谱仪（GC）是一种常用的分离和分析工具，广泛应用于食品、药品、环境和化学等领域。
为了确保GC的安全性、可靠性和准确性，各国都制定了一系列的法规和标准来规范GC的使用和运行。
以下是常见的气相色谱仪法规要求的总结。
一、国际电工委员会（IEC）标准1. IEC 61010-1：这是一项国际标准，规定了电气安全要求，包括气相色谱仪的保护措施、操作和维护。
二、美国食品药品监督管理局（FDA）标准1. 21 CFR Part 11：该标准是美国FDA针对电子记录和电子签名的要求，要求GC的数据记录和报告必须符合电子记录的有效性、完整性和可追溯性要求。
三、欧洲药典（EP）标准1. 2.2.46：该标准规定了GC的性能要求和分析条件，并详细描述了分离和检测方法。
四、美国环保局（EPA）标准1. TO-15：该标准规定了大气中挥发性有机化合物（VOCs）的分析方法，要求GC的分辨率和灵敏度能够满足对有害物质的检测要求。
五、国际标准化组织（ISO）标准1. ISO 6142：该标准规定了气相色谱仪用于校准气体的要求，包括校准气体的纯度、稳定性和跟踪能力等。
六、中国药典（ChP）标准1. 基础电离质谱法：该标准规定了基础电离质谱法在药物分析中的应用要求，包括GC/MS技术的仪器要求和分析方法。
七、各国环境监测标准1. 水和空气中有毒有害物质的分析标准：各国环境监测机构根据实际需要，制定了一系列针对土壤、水和大气中有毒有害物质的分析方法，要求GC的分析方法符合国家标准。
在满足以上法规和标准要求的基础上，气相色谱仪的用户还应注意以下方面：1. 仪器的安全操作：包括正确接地、电源连接、着火和爆炸防范等安全措施。
2. 样品的准备和处理：样品的准备和处理应符合标准操作程序，确保样品在分析过程中的一致性和可比性。
3. 数据的可靠性和有效性：GC的数据记录应具有完整性、精确性和准确性，并且能够进行回溯和追踪。
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。
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。
气相色谱标准气相色谱（Gas Chromatography，GC）是一种分离和分析化合物的技术，广泛应用于化学、生物化学、环境监测、食品安全等领域。
气相色谱标准是保障气相色谱分析准确性和可靠性的重要依据，下面将对气相色谱标准进行详细介绍。
首先，气相色谱标准的制定是基于国际上公认的分析方法和标准样品的。
在进行气相色谱分析时，需要根据不同的样品性质和分析要求，选择合适的分析方法和标准样品。
这些方法和样品通常由国际标准化组织（ISO）和美国国家标准局（NIST）等权威机构发布和制定，确保了气相色谱分析的准确性和可靠性。
其次，气相色谱标准涉及到仪器设备的要求和规范。
气相色谱仪作为气相色谱分析的核心设备，其性能和规格对分析结果具有重要影响。
因此，气相色谱标准中通常包括了对仪器设备的要求和规范，包括但不限于分辨率、灵敏度、重复性、稳定性等指标的要求，以及仪器设备的维护和校准方法。
这些要求和规范的制定，有助于保证气相色谱分析的准确性和可靠性。
另外，气相色谱标准还涉及到分析条件和操作流程的规定。
在进行气相色谱分析时，需要严格控制分析条件和操作流程，以确保分析结果的准确性和可重复性。
因此，气相色谱标准中通常包括了对分析条件和操作流程的规定，包括但不限于进样量、进样方式、柱温、载气流速、检测器温度、分析时间等方面的要求，以及分析前的样品处理方法和分析后的数据处理方法。
这些规定的制定，有助于规范气相色谱分析的过程，提高分析结果的准确性和可靠性。
最后，气相色谱标准还包括了对分析结果的评定和报告的要求。
在进行气相色谱分析后，需要对分析结果进行评定，并按照标准要求编制分析报告。
气相色谱标准中通常包括了对分析结果的评定标准和报告格式的规定，以及对分析过程中可能出现的问题和异常情况的处理方法。
这些要求和规定的制定，有助于保证气相色谱分析结果的准确性和可靠性，并便于结果的比对和交流。
综上所述，气相色谱标准是保障气相色谱分析准确性和可靠性的重要依据，涉及到分析方法和标准样品、仪器设备、分析条件和操作流程、分析结果的评定和报告等方面的要求和规定。
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。
CD-ROM 8091 - 1Revision 0December 1996METHOD 8091NITROAROMATICS AND CYCLIC KETONES BY GAS CHROMATOGRAPHY1.0SCOPE AND APPLICATION1.1Method 8091 is a gas chromatographic (GC) method used to determine the concentration of nitroaromatics and cyclic ketones. It describes wide-bore, open-tubular, capillary column gas chromatography procedures using either electron capture (ECD) or nitrogen-phosphorous (NPD)detectors. The following RCRA analytes can be determined by this method:CompoundCAS No.a 1,4-Dinitrobenzene 100-25-42,4-Dinitrotoluene 121-14-22,6-Dinitrotoluene 606-20-21,4-Naphthoquinone 130-15-4Nitrobenzene98-95-3Pentachloronitrobenzene82-68-8Chemical Abstract Service Registry Number.a1.2 The following non-RCRA analytes can also be determined by this method:CompoundCAS No.a Benefin 1861-40-1Butralin33629-47-91-Chloro-2,4-dinitrobenzene 97-00-71-Chloro-3,4-dinitrobenzene 610-40-21-Chloro-2-nitrobenzene 88-73-31-Chloro-4-nitrobenzene 100-00-52-Chloro-6-nitrotoluene 83-42-14-Chloro-2-nitrotoluene 89-59-84-Chloro-3-nitrotoluene 89-60-12,3-Dichloronitrobenzene 3209-22-12,4-Dichloronitrobenzene 611-06-33,5-Dichloronitrobenzene 618-62-23,4-Dichloronitrobenzene 99-54-72,5-Dichloronitrobenzene89-61-2Compound CAS No.aDinitramine29091-05-21,2-Dinitrobenzene528-29-01,3-Dinitrobenzene99-65-0Isopropalin33820-53-01,2-Naphthoquinone524-42-52-Nitrotoluene88-72-23-Nitrotoluene99-08-14-Nitrotoluene99-99-0Penoxalin (Pendimethalin)40487-42-1Profluralin26399-36-02,3,4,5-Tetrachloronitrobenzene879-39-02,3,5,6-Tetrachloronitrobenzene117-18-01,2,3-Trichloro-4-nitrobenzene17700-09-31,2,4-Trichloro-5-nitrobenzene89-69-02,4,6-Trichloronitrobenzene18708-70-8Trifluralin1582-09-81.3This method is restricted to use by, or under the supervision of, analysts experienced in the use of gas chromatographs and skilled in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method.2.0SUMMARY OF METHOD2.1Method 8091 provides gas chromatographic conditions for the detection of ppb concentrations of nitroaromatics and cyclic ketones in water and soil or ppm concentrations in waste samples. Prior to use of this method, appropriate sample extraction techniques must be used for environmental samples (refer to Chapter Two and Method 3500). Both neat and diluted organic liquids (Method 3580) may be analyzed by direct injection. Analysis is accomplished by gas chromatography utilizing an instrument equipped with wide bore capillary columns and one or more electron capture detectors or nitrogen-phosphorus detectors (NPD).3.0INTERFERENCES3.1Refer to Method 3500, 3600, and 8000.3.2The electron capture detector responds to all electronegative compounds. Therefore, interferences are possible from other halogenated compounds, as well as phthalates and other oxygenated compounds such as organonitrogen, organosulfur, and organophosphorus compounds. Second column confirmation or GC/MS confirmation is necessary to ensure proper analyte identification unless previous characterization of the sample source will ensure proper identification.3.3Contamination by carryover can occur whenever high-concentration and low-concentration samples are sequentially analyzed. To reduce carryover, the syringe used for injection must be thoroughly rinsed between samples with solvent. Whenever a highly concentrated sample extract is encountered, it should be followed by the analysis of a solvent blank to check for CD-ROM8091 - 2Revision 0December 1996CD-ROM 8091 - 3Revision 0December 1996cross-contamination. Additional solvent blanks interspersed with the sample extracts should be considered whenever the analysis of a solvent blank indicates cross-contamination problems.3.4In certain cases some compounds coelute on either one or both columns. In these cases the compounds must be reported as coeluting. The mixture can be reanalyzed by GC/MS techniques if concentration permits (see Method 8270).3.4.1DB-5 column:2,4,6-trichloronitrobenzene/1,3-dinitrobenzene1-chloro-2,4-dinitrobenzene/1-chloro-3,4-dinitrobenzene/1,2,3-trichloro-4-nitrobenzene 3.4.2DB-1701 column:2,4-dichloronitrobenzene/4-chloro-3-nitrotoluene 2,4,6-trichloronitrobenzene/1,4-naphthoquinone1-chloro-2,4-dinitrobenzene/2,3,4,5-tetrachloronitrobenzene3.4.3In addition, on the DB-5 column, 2,5-dichloronitrobenzene is not well resolved from 4-chloro-3-nitrotoluene. Also, Trifluralin is not well resolved from Benefin. On the DB-1701 column, compound pairs that are not well resolved include 4-nitrotoluene/1-chloro-3-nitrobenzene and Trifluralin/Benefin.3.5Solvents, reagents, glassware, and other sample processing hardware may yield discrete artifacts and/or elevated baselines causing misinterpretation of gas chromatograms. All these materials must be demonstrated to be free from interferences under the conditions of the analysis,by analyzing reagent blanks.4.0APPARATUS AND MATERIALS4.1Gas chromatograph: An analytical system complete with a gas chromatograph suitable for on-column and split/splitless injection, and all accessories, including syringes, analytical columns,gases, electron capture detectors or nitrogen-phosphorus detectors. A GC equipped with a single GC column and detector or other configurations of column and detector is also acceptable. A data system for measuring peak areas and/or peak heights, and dual display of chromatograms is recommended.4.1.1Suggested GC Columns: Alternative columns may be used to provide the separation needed to resolve all target analytes listed in Sec. 1.1 of this method. Refer to Chapter One for additional information regarding column performance and QA requirements.4.1.1.1Column 1 - 30 m x 0.53 mm ID fused-silica open- tubular column,crosslinked and chemically bonded with 95 percent dimethyl and 5 percent diphenyl-polysiloxane (DB-5, RT -5, SPB-5, or equivalent), 0.83 µm or 1.5 µm film x thickness.4.1.1.2Column 2 - 30 m x 0.53 mm ID fused-silica open-tubular columncrosslinked and chemically bonded with 14 percent cyanopropylphenyl and 86 percent dimethyl-polysiloxane (DB-1701, RT -1701, or equivalent), 1.0 µm film thickness.xCD-ROM 8091 - 4Revision 0December 19964.1.2Splitter: If the splitter approach to dual column injection is chosen, following are three suggested splitters. An equivalent splitter is acceptable. See Sec. 7.5.1 for a caution on the use of splitters.4.1.2.1Splitter 1 - J&W Scientific press-fit Y-shaped glass 3-way union splitter(J&W Scientific, Catalog No. 705-0733).4.1.2.2Splitter 2 - Supelco 8-in glass injection tee, deactivated (Supelco,Catalog No. 2-3665M).4.1.2.3Splitter 3 - Restek Y-shaped fused-silica connector (Restek, Catalog No.20405).4.1.3Column rinsing kit (optional): Bonded-phase column rinse kit (J&W Scientific,Catalog No. 430-3000 or equivalent).4.2Microsyringes - 100 µL, 50 µL, 10 µL (Hamilton 701 N or equivalent), and 50 µL (Blunted,Hamilton 705SNR or equivalent).4.3Balances - Analytical, 0.0001 g, Top-loading, 0.01 g.4.4Volumetric flasks, Class A - 10 mL to 1000 mL.5.0REAGENTS5.1Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, 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 chemicals are of sufficiently high purity to permit their use without affecting the accuracy of the determinations.5.2Solvents 5.2.1Hexane, C H - Pesticide quality or equivalent.6145.2.2Acetone, CH COCH - Pesticide quality or equivalent.335.2.3Isooctane, (CH )CCH CH(CH ) - Pesticide quality or equivalent.332325.3Stock standard solutions (1000 mg/L): Can be prepared from pure standard materials or can be purchased as certified solutions.5.3.1Prepare stock standard solutions by accurately weighing about 0.0100 g of pure compound. Dissolve the compound in isooctane or hexane and dilute to volume in a 10 mL volumetric flask. (Isooctane is preferred because it is less volatile than hexane.) If compound purity is 96 percent or greater, the weight can be used without correction to calculate the concentration of the stock standard solution. Commercially prepared stock standard solutions can be used at any concentration if they are certified by the manufacturer or by an independent source.5.3.2For those compounds which are not adequately soluble in hexane or isooctane,dissolve the compound initially with a small volume of toluene, ethyl acetate or acetone and dilute to volume with isooctane or hexane.5.4Composite stock standard: Can be prepared from individual stock solutions. For composite stock standards containing less than 25 components, transfer exactly 1 mL of each individual stock solution at 1000 mg/L, add solvent, mix the solutions, and bring to volume in a 25 mL volumetric flask. For example, for a composite containing 20 individual standards, the resulting concentration of each component in the mixture, after the volume is adjusted to 25 mL, will be 40 mg/L. This composite solution can be further diluted to obtain the desired concentrations. For composite stock standards containing more than 25 components, use volumetric flasks of the appropriate volume (e.g., 50 mL, 100 mL).5.5Calibration standards: These should be prepared at a minimum of five concentrations by dilution of the composite stock standard with isooctane or hexane. The standard concentrations should correspond to the expected range of concentrations present in the field samples and should bracket the linear range of the detector.5.6Recommended internal standard: Prepare a solution of 1000 mg/L of hexachlorobenzene. For spiking, dilute this solution to 50 ng/µL. (This concentration may need to be more dilute depending on the detector chosen and its sensitivity. The internal standard response should be approximately 50 to 90% of full scale.) Use a spiking volume of 10.0 µL/mL of extract. The spiking concentration of the internal standards should be kept constant for all samples and calibration standards.5.7Recommended surrogate standard: Monitor the performance of the method using surrogate compounds. Surrogate standards are added to all samples, method blanks, matrix spikes, and calibration standards. Prepare a solution of 1000 mg/L of 1-chloro-3-nitrobenzene and dilute it to 10 ng/µL. (This concentration may need to be adjusted depending on the detector chosen and its sensitivity. The surrogate standard response should be approximately 100% of full scale.) Usea spiking volume of 100 µL for a 1 L aqueous sample.5.8Store the standard solutions (stock, composite, calibration, internal, and surrogate) at 4E C or cooler in polytetrafluoroethylene(PTFE)-sealed containers in the dark. All standard solutions must be replaced after six months or sooner if routine QC (Sec. 8.0) indicates a problem.6.0SAMPLE COLLECTION, PRESERVATION, AND HANDLING6.1See the introductory material to this chapter, Organic Analytes, Sec. 4.1.6.2Extracts must be stored in the dark at or below 4E C and analyzed within 40 days of extraction.7.0PROCEDURE7.1Extraction and Cleanup:7.1.1Refer to Chapter Two and Method 3500 for guidance on choosing the appropriateextraction procedure. In general, water samples are extracted at a pH between 5 to 9 with CD-ROM8091 - 5Revision 0December 1996methylene chloride, using either Method 3510 or 3520. Solid samples are extracted using any of the extraction methods for solids listed in Method 3500, as appropriate.7.1.2If necessary, the samples may be cleaned up using Method 3620 (Florisil) and/orMethod 3640 (Gel Permeation Chromatography). See Chapter Two, Sec. 2.0 and Method 3600 for general guidance on cleanup and method selection. Method 3660 is used for sulfur removal.7.1.3Prior to gas chromatographic analysis, the extraction solvent needs to beexchanged to hexane. The exchange is performed using the K-D procedures listed in each of the extraction methods. Any methylene chloride remaining in the extract will cause a very broad solvent peak.7.2Gas Chromatographic Conditions: Retention time information for each of the analytes is presented in Tables 1 and 3. The recommended GC operating conditions are provided in Tables 2 and 4. Figures 1, 2, and 3 illustrate typical chromatography of the method analytes for both columns when operated at the conditions specified.7.3Calibration:7.3.1Prepare calibration standards using the procedures in Sec. 5.0. Refer to Method8000, Sec. 7.0 for proper calibration procedures. The procedure for internal or external calibration may be used.7.3.2Refer to Method 8000, Sec. 7.0 for the establishment of retention time windows.7.4Gas chromatographic analysis:7.4.1Method 8000, Sec. 7.0 provides instructions on calibration, establishing retentiontime windows, the analysis sequence, appropriate dilutions, and identification criteria.7.4.2Automatic injections of 1 µL are recommended. Hand injections of no more than2 µL may be used if the analyst demonstrates quantitation precision less than or equal to 10percent relative standard deviation. The solvent flush technique may be used if the amount of solvent is kept at a minimum. If the internal standard calibration technique is used, add10 µL of the internal standard to each mL of sample extract prior to injection.7.4.3Tentative identification of an analyte occurs when a peak from a sample extractfalls within the absolute retention time window. Normally, confirmation is necessary.Confirmation techniques include analysis on a second column with dissimilar stationary phase, by GC/MS (full scan or SIM) or by using a different detector and getting comparable data. See Sec. 7.0 of Method 8000 on "Compound Identification" for further information.7.4.3.1If partially overlapping or coeluting peaks are present, install columnswith a dissimilar liquid phase or use a GC/MS technique. Interferences that preventanalyte identification and/or quantitation may possibly be removed by the cleanuptechniques mentioned above.7.4.4Record the volume injected to the nearest 0.05 µL and the resulting peak size inarea units or peak height. Using either the internal or the external calibration procedure (Method 8000), determine the quantity of each component peak in the sample chromatogram which corresponds to the compounds used for calibration purposes.CD-ROM8091 - 6Revision 0December 19967.4.4.1If the responses exceed the linear range of the system, dilute the extractand reanalyze. Peak height measurements are recommended, rather than peak areaintegration, when overlapping peaks may cause errors in area integration.7.4.4.2If the peak response is less than 2.5 times the baseline noise level, thevalidity of the quantitative result may be questionable. The analyst should consult withthe source of the sample to determine whether further concentration of the sample iswarranted.7.4.5Determine the concentration of each identified analyte using the calculationformulae in Sec. 7.0 of Method 8000.7.5Instrument Maintenance:7.5.1Injection of sample extracts from waste sites often leaves a high boiling residuein the injection port area, splitters when used, and the injection port end of the chromatographic column. This residue affects chromatography in many ways (i.e., peak tailing, retention time shifts, analyte degradation, etc.) and, therefore, instrument maintenance is very important. Residue buildup in a splitter may limit flow through one leg and therefore change the split ratios. If this occurs during an analytical run, the quantitative data may be incorrect.Proper cleanup techniques will minimize the problem and instrument QC will indicate when instrument maintenance is required.7.5.2Suggested chromatograph maintenance: Corrective measures may require anyone or more of the following remedial actions. Also see Sec. 7.0 in Method 8000 for additional guidance on corrective action for capillary columns and the injection port.7.5.2.1Splitter connections: For dual columns which are connected using apress-fit Y-shaped glass splitter or a Y-shaped fused-silica connector, clean anddeactivate the splitter or replace with a cleaned and deactivated splitter. Break off thefirst few inches (up to one foot) of the injection port side of the column. Remove thecolumns and solvent backflush according to the manufacturer's instructions. If theseprocedures fail to eliminate the degradation problem, it may be necessary to deactivatethe metal injector body and/or replace the columns.7.5.2.2Column rinsing: The column should be rinsed with several columnvolumes of an appropriate solvent. Both polar and nonpolar solvents are recommended.Depending on the nature of the sample residues expected, the first rinse might be water,followed by methanol and acetone; methylene chloride is a satisfactory final rinse and insome cases may be the only solvent required. The column should then be filled withmethylene chloride and allowed to remain flooded overnight to allow materials within thestationary phase to migrate into the solvent. The column is then flushed with freshmethylene chloride, drained, and dried at room temperature with a stream of ultrapurenitrogen passing through the column.8.0QUALITY CONTROL8.1Refer to Chapter One and Method 8000 for specific quality control (QC) procedures. Quality control procedures to ensure the proper operation of the various sample preparation and/or sample introduction techniques can be found in Methods 3500 and 5000. Each laboratory should CD-ROM8091 - 7Revision 0December 1996maintain a formal quality assurance program. The laboratory should also maintain records to document the quality of the data generated.8.2Quality control procedures necessary to evaluate the GC system operation are found in Method 8000, Sec. 7.0 and includes evaluation of retention time windows, calibration verification and chromatographic analysis of samples.8.3Initial Demonstration of Proficiency - Each 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 following operations whenever new staff are trained or significant changes in instrumentation are made. See Method 8000, Sec. 8.0 for information on how to accomplish this demonstration.8.4Sample Quality Control for Preparation and Analysis - The laboratory must also have procedures for documenting the effect of the matrix on method performance (precision, accuracy, and detection limit). At a minimum, this includes the analysis of QC samples including a method blank, a matrix spike, a duplicate, and a laboratory control sample (LCS) in each analytical batch and the addition of surrogates to each field sample and QC sample.8.4.1Documenting the effect of the matrix should include the analysis of at least onematrix spike and one duplicate unspiked sample or one matrix spike/matrix spike duplicate pair.The decision on whether to prepare and analyze duplicate samples or a matrix spike/matrix spike duplicate must be based on a knowledge of the samples in the sample batch. If samples are expected to contain target analytes, then laboratories may use one matrix spike and a duplicate analysis of an unspiked field sample. If samples are not expected to contain target analytes, laboratories should use a matrix spike and matrix spike duplicate pair.8.4.2 A Laboratory Control Sample (LCS) should be included with each analytical batch.The LCS consists of an aliquot of a clean (control) matrix similar to the sample matrix and of the same weight or volume. The LCS is spiked with the same analytes at the same concentrations as the matrix spike. When the results of the matrix spike analysis indicate a potential problem due to the sample matrix itself, the LCS results are used to verify that the laboratory can perform the analysis in a clean matrix.8.4.3See Method 8000, Sec. 8.0 for the details on carrying out sample quality controlprocedures for preparation and analysis.8.5Surrogate recoveries - The laboratory must evaluate surrogate recovery data from individual samples versus the surrogate control limits developed by the laboratory. See Method 8000, Sec. 8.0 for information on evaluating surrogate data and developing and updating surrogate limits.8.6It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Whenever possible, the laboratory should analyze standard reference materials and participate in relevant performance evaluation studies.CD-ROM8091 - 8Revision 0December 19969.0METHOD PERFORMANCE9.1Table 1 lists the retention times of the target analytes. Figure 1 shows a chromatogram of the target analytes eluted from a pair of DB-5/DB-1701 columns and detected using electron capture detectors (ECD) under the GC conditions listed in Table 2.9.2Table 3 provides the retention times and recovery data of the target analytes. GC conditions used during the recovery study are listed in Table 4. Chromatograms of the standard mixes used in the recovery study are provided in Figures 2 and 3.9.3The laboratory should perform a Method Detection Limit (MDL) study and generate its own performance data (precision and accuracy) for matrix spike and surrogate compounds. Refer to Method 8000 for guidance.10.0REFERENCES1.Lopez-Avila, V., Baldin, E., Benedicto, J, Milanes, J., Beckert, W.F., "Application ofOpen-Tubular Columns to SW 846 GC Methods", final report to the U.S. Environmental Protection Agency on Contract 68-03-3511, Mid-Pacific Environmental Laboratory, Mountain View, CA, 1990.2.Tsang, S., Marsden, P.J., Chau, N., "Performance Data for Methods 8041, 8091, 8111, and8121A", draft report to U.S. Environmental Protection Agency on Contract 68-W9-0011, Science Applications International Corp., San Diego, CA, 1992.CD-ROM8091 - 9Revision 0December 1996CD-ROM 8091 - 10Revision 0December 1996TABLE 1RETENTION TIMES OF THE NITROAROMATICS AND CYCLIC KETONESa ___________________________________________________________________________DB-5DB-1701Compound —————————————————poundCAS No.RT(min)RT(min)1Nitrobenzene 98-95-3 4.71 4.2322-Nitrotoluene 88-72-2 6.08 5.3233-Nitrotoluene 99-08-1 6.93 6.2244-Nitrotoluene99-99-07.35 6.7351-Chloro-3-nitrobenzene (Surr.)121-73-37.66 6.8561-Chloro-4-nitrobenzene 100-00-57.97.1571-Chloro-2-nitrobenzene 88-73-38.097.7882-Chloro-6-nitrotoluene 83-42-19.618.3294-Chloro-2-nitrotoluene 89-59-89.768.62103,5-Dichloronitrobenzene 618-62-210.42 8.84112,5-Dichloronitrobenzene 89-61-211.46 10.62122,4-Dichloronitrobenzene 611-06-311.7310.84134-Chloro-3-nitrotoluene 89-60-111.3110.84143,4-Dichloronitrobenzene 99-54-712.24 11.04152,3-Dichloronitrobenzene 3209-22-112.5812.01162,4,6-Trichloronitrobenzene 18708-70-813.97 12.31171,4-Naphthoquinone130-15-412.9812.31181,2,4-Trichloro-5-nitrobenzene 89-69-015.9714.46191,4-Dinitrobenzene 100-25-413.4114.72202,6-Dinitrotoluene 606-20-214.4415.16211,3-Dinitrobenzene99-65-013.9715.68221,2,3-Trichloro-4-nitrobenzene 17700-09-317.6116.51232,3,5,6-Tetrachloronitrobenzene 117-18-019.4117.11241,2-Dinitrobenzene 528-29-014.7617.51252,4-Dinitrotoluene121-14-216.9218.16261-Chloro-2,4-dinitrobenzene 97-00-717.8519.55272,3,4,5-Tetrachloronitrobenzene 879-39-021.5119.55281-Chloro-3,4-dinitrobenzene 610-40-217.8519.8529Trifluralin 1582-09-821.81 20.3130Benefin1861-40-121.9420.4631Pentachloronitrobenzene 82-68-825.1322.3332Profluralin 26399-36-025.3923.8133Dinitramine 29091-05-226.4527.0634Butralin 33629-47-932.4131.0335Isopropalin33820-53-032.7131.33(continued)CD-ROM 8091 - 11Revision 0December 1996TABLE 1 (continued)RT (min)Compound —————————— poundCAS No.DB-5 DB-170136Penoxalin (Pendimethalin)40487-42-133.0531.67371,2-Naphthoquinone 524-42-5 c c 382-Chloro-4-nitrotoluene 121-86-8 b b Int. Std.Hexachlorobenzene118-74-123.1818.72See Table 2 for operating conditions.a b Not available. c Not detected at 1 ng per injection.NOTE: These data are from Reference 1.TABLE 2DUAL COLUMN GC OPERATING CONDITIONS FOR NITROAROMATICSGC Instrument: Varian 6000 with dual electron capture detectors Column 1:Type: DB-5 (J&W Scientific)Dimensions: 30 m x 0.53 mm ID Film Thickness: 1.5 µm Column 2:Type: DB-1701 (J&W Scientific)Dimensions: 30 m x 0.53 mm ID Film Thickness: 1.0 µmType of splitter: J&W Scientific press-fit Y-shaped inlet splitter Carrier gas flowrate (mL/min): 6 (Helium)Makeup gas flowrate (mL/min): 20 (Nitrogen)Injector temperature: 250E C Detector temperature: 320E CTemperature program: 120E C (1.0 min hold) to 200E C (1 min hold) at 3E C/minthen to 250E C (4 min hold) at 8E C/min.Injection volume: 2 µLType of injection: Flash vaporization Solvent: Hexane Range: 10Attenuation: 64 (DB-1701)/64 (DB-5)CD-ROM 8091 - 12Revision 0December 1996RETENTION TIMES AND RECOVERY OF NITROAROMATICSAnalyte(ng/g)(%)R , minSpiking Conc.Recovery % RSDt MIX 11,2:3,4-diepoxy butane 3.235,0002218.1Nitrobenzene 11.515,00085 6.92-Nitrotoluene 14.135,00080 5.43-Nitrotoluene 15.525,00083 6.84-Nitrotoluene16.225,00097 6.21-Chloro-3-nitrobenzene 16.64100103 6.2a 2,3-Dichloronitrobenzene 22.481001027.31,4-Naphthoquinone 23.292003523.11,3-Dinitrobenzene 24.254008013.11,2-Dinitrobenzene 24.692009917.03-Nitroaniline 25.4410,0005417.82,4-Dinitrotoluene 26.952007513.94-Nitroaniline 28.915,0005329.6Trifluralin30.25200127 4.4Pentachloronitrobenzene 32.26100129 5.84-Nitroquinoline-1-oxide36.055,0006.718.5MIX 21-Chloro-3-nitrobenzene 16.6410098 3.0a 2-Nitroaniline 22.875,00088 3.61,4-Dinitrobenzene 23.82200142 2.92,6-Dinitrotoluene 24.49200192 6.25-Nitro-o-toluidine28.915,0006042Recommended Surrogate an = 5 samples NOTE:This table is from Reference 2. See Table 4 for operating conditions used in this table.GC OPERATING CONDITIONS USED FOR RECOVERY DATA IN TABLE 3 Column: DB-5 30 m x 0.53 mm ID.Carrier gas: Nitrogen at 6 mL/min with hydrogen at 30 mL/min.Total nitrogen flow: 60 mL/min (carrier and makeup).Injector: Packed, megabore liner at 200E C.Detector: ECD at 300E C.Temperature Program:70E C held for 1.5 minutes4E C/min to 170E C8E C/min to 275E C and held for 5.4 minutesThe total run time was 45 minutes.NOTE:This table is from Reference 2.CD-ROM8091 - 13Revision 0December 1996CD-ROM 8091 - 14Revision 0December 1996GC/ECD CHROMATOGRAM OF NITROAROMATICS ANALYZED ON A DB-5/DB-1701 FUSED-SILICA, OPEN-TUBULAR COLUMN PAIRSee Table 2 for operating conditions.CD-ROM 8091 - 15Revision 0December 1996See Table 4 for operating conditions.CD-ROM 8091 - 16Revision 0December 1996See Table 4 for operating conditions.CD-ROM 8091 - 17Revision 0December 1996METHOD 8091NITROAROMATICS AND CYCLIC KETONES BY GAS CHROMATOGRAPHY。
