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TLC常用展开剂及应用

TLC常用展开剂及应用
TLC常用展开剂及应用

1、生物碱

(1)沉淀反应——碘化汞钾试剂→白色或浅黄色沉淀

碘化铋钾试剂→橘红色沉淀

碘—碘化钾试剂→浅棕或暗棕色沉淀

硅钨酸试剂→浅黄或黄棕色沉淀

磷钨酸试剂→浅黄色沉淀

磷钼酸试剂→白色或淡黄色沉淀

苦味酸试剂→黄色结晶或非结晶形沉淀

鞣酸试剂→棕黄色沉淀

氯化金试剂→黄色结晶

氯化铂试剂→白色结晶

雷氏铵盐→红色无定形沉淀

(2)薄层层析检查:吸附剂——碱性氧化铝(Ⅲ级,干法铺板)

硅胶G(稀碱湿法铺板)

展开剂——氯仿:甲醇

显色——UV;碘化铋钾

2、氨基酸、多肽、蛋白质

(1)加热沉淀试验:加热煮沸→混浊或沉淀(蛋白质)

+5%H2SO4(不加热)→混浊或沉淀

(2)双缩脲反应:+40%NaOH,1%CuSO4 →紫色、红色或紫红色(多肽、蛋白质)(3)茚三酮反应:+0.2%茚三酮试液→蓝或蓝紫色(氨基酸、多肽、蛋白质)

(4)吲哚醌反应:+吲哚醌试液→各种颜色(氨基酸)

(5)Millon反应:+Hg,H2NO2 →红色(蛋白质分子中有酪氨酸组成)

(6)Hopkins-Cole反应:+乙醛酸,浓硫酸→各色(蛋白质分子中有色氨酸组成)(7)氨基酸的薄层层析检查:吸附剂——硅胶G

展开剂—— n-BuOH,n-BuOH:HAc:H2O

显色剂——0.25%茚三酮试液→紫红色斑点

3、有机酸

(1)PH试纸检查

(2)溴酚兰试液:喷洒→蓝色背景黄色斑点

(3)薄层层析检查:吸附剂——硅胶G或酸性氧化铝

展开剂—— C6H6:EtOH

显色剂——0.1%溴酚兰试液→黄色

4、酚类和鞣质

(1)FeCl3试剂:+1%FeCl3试液→蓝、暗绿或蓝紫色

(2)三氯化铁-铁氰化钾试剂:喷洒→蓝色斑点

(3)香草醛-盐酸试剂:喷洒→红色(间苯二酚、间苯三酚)

(4)重氮盐试剂:+对硝基苯胺、亚硝酸钠→红色

(5)薄层层析检查:吸附剂——硅胶G或纤维素

展开剂—— n-BuOH:HAc:H2O;15%HAc

显色剂——1% FeCl3试液

1%三氯化铁-1%铁氰化钾试液→蓝、绿或黑色

鞣质与酚类的区别:+明胶——沉淀

上清液+1%FeCl3试液→蓝、暗绿或蓝紫色

5、糖和苷

(1)斐林试剂:+硫酸铜、酒石酸钾钠——砖红色沉淀(还原糖)

(—)+1%HCl +NaOH 沉淀(苷元)

△30min 上清液(+)(多糖、苷)

(2)Molish反应:+α-萘酚-浓硫酸→紫红色环

(3)银镜反应:+0.1N硝酸银、5N氨水→银褐色(还原糖)

(4)薄层层析检查::吸附剂——硅胶G或纤维素

展开剂—— n-BuOH:Pd:H2O;15%HAc

显色剂——苯胺-邻苯二甲酸

6、皂苷

(1)泡末试验:振摇→大量持续性泡末

+0.1M HCl 二管泡末高度相同(三萜皂苷)

+0.1M NaOH 碱管高于酸管(甾体皂苷)

(2)溶血试验:+2%红血球悬浮液→溶血

(3)Lieberman—Burchard反应:+醋酐-浓硫酸——紫红色(三萜皂苷)

黄-红-紫-污绿(甾体皂苷)

7、甾体

(1)Lieberman—Burchard反应:+醋酐-浓硫酸→黄-红-紫-污绿

(2)氯仿-浓硫酸反应:+氯仿-浓硫酸氯仿层→红或青色

硫酸层→绿色荧光

(3)五氯化锑或三氯化锑反应:+SbCl3或SbCl5 →红色

(4)薄层层析检查:吸附剂——中性氧化铝或硅胶G

展开剂—— C6H6-MeOH;CHCl3-MeOH

显色剂—— 10%磷钼酸→蓝-蓝紫色

5%三氯化锑试液→红、棕红或绿色

8、黄酮

(1)盐酸-镁粉反应:+HCl-Mg →红色

(2)三氯化铝反应:+AlCl3 →黄色

(3)浓氨水反应:+NH3 →亮黄或橙色

(4)薄层层析检查:吸附剂——聚酰胺或硅胶G

展开剂—— MeOH-H2O;EtOH-H2O

显色剂—— UV→亮黄或黄绿色荧光

1%三氯化铝试液→亮黄色

9、香豆素、内酯

(1)开闭环反应:+1%NaOH→澄清+2%HCl→混浊

(2)异羟污酸铁反应:+7%盐酸羟胺、10%KOH △+稀HCl、1%FeCl3 →红色(3)重氮盐试剂:+对硝基苯胺、亚硝酸钠→红色

(4)薄层层析检查:吸附剂——酸性硅胶G或硅胶G 或酸性氧化铝

展开剂——甲苯-乙酸乙酯-甲酸(5:4:1)

显色剂—— UV→蓝色荧光

异羟污酸铁试液→红色

10、强心苷

(1)Kedde试剂:+3,5-二硝基苯甲酸试液→紫红色

(2)Baljet试剂:+碱性苦味酸试液→橙或橙红色

(3)Legal试剂:+亚硝酰铁氰化钠试液→紫红色

(4)K-K反应:+FeCl3/冰HAc、浓H2SO4→上层绿~蓝色(2-去氧糖)

界面红棕色

(5)薄层层析检查:吸附剂——硅胶G 或中性氧化铝

展开剂—— n-BuOH:HAc:H2O(4:1:5)

显色剂——碱性3,5-二硝基苯甲酸试液→紫红色

碱性苦味酸试液→橙红色

11、蒽醌

(1)碱液反应:+10%NaOH →红色+H2O2 →红色不褪+H+ →红色褪去

(2)醋酸镁反应:+1%MgAc2 →红色

(3)薄层层析检查:吸附剂——硅胶G

展开剂——Pet:EtOAc

显色剂—— UV→黄色荧光

5%NaOH →红色

12、挥发油、油脂

(1)油斑检查:油斑挥发→挥发油;油斑不消失→油脂或类脂

(2)磷钼酸反应:喷洒5%磷钼酸试液→蓝色(油脂、三萜、甾醇)

TLC Visualization Reagents

This is a brief selection of the many available TLC visualization reagents. Below each title is the type of compounds or structure which can be detected with the specific reagent. When beginning work with these reagents, acquired any MSDS (material safety data sheets) to see if there are any extra precautions needed in safely using them.

Before spraying, plates should be well dried in the hood of residual solvents and components. Amines and organic acids used in the mobile phases may adversely affect the visualization reaction being attempted. If heating to remove these components is done, consideration should be given so that loss of components or their decomposition is avoided (by lowering the temperature or using a shorter t ime in the oven).

Always spray any of these reagents onto plates in a well ventilated hood while wearing safety glasses. Also apply moderate amounts to the plate so it always appears dull and flat (if it looks wet, you have sprayed too much). You can alway s overspray to enhance the detection.

When information about the results of using the visualization reagents was available, this was put under each reagent as ‘Results’. If not give, the user will have to do a few experiments to see what the results might be.

Always remember to look under normal light and also short and long wavelength UV light

so as not to miss any possibilities.

Many of the reagents for these visualizers can be found in the EMD Chemicals catalog or on the website

(https://www.doczj.com/doc/4e8483240.html,).

Aluminium chloride

For flavonoids

Spray plate with a 1% ethanolic solution of aluminum chloride.

Results: Yellow fluorescence in long wavelength UV light (360nm)

4-Aminoantipyrine/potassium hexacyanferrate (III) (Emerson reaction)

(Emerson reagent) for the detection of phenols and arylamines

Solution I: 1g aminoantipyrine (4-aminophenazone) in 100ml 80% ethanol

Solution II: 4g potassium hexacyanoferrate (III) in 20ml water, fill to 100ml with ethano l Procedure:

Spray with solution I

Dry 5 minutes with warm air

Place chromatogram in a chamber with vapor from 25% ammonium solution, making sure that the layer does

not contact the liquid.

Results: Red-orange to salmon pink spots

2-Aminoethyl diphenylborate, see Ethanolamine diphenylborate

Ammonium metavanadate, ammonium monovanadate, see Vanadium(V) / sulfuric acid Ammonium molydbate

For detection of phosphoric acid derivatives

Solution I: 1M perchloric acid in water/acetone (1:1)

Solution II: ammonium molybdate soln: 5g (NH4)6Mo7O24.4 H2O in 35ml semi-conc. Nitric acid and 65ml water.

Solution III: Tin (II) chloride soln: 0.5g SnCl2.2 H2O in 100ml 0.5M hydrochloric acid: Dry developed chromatogram and heat to 60 C

Hydrolyse di- and triphosphates by spraying perchloric acid (solution I) onto the warm plate. After spraying 2

times, dry plate slowly at 50 C. Amidophosphates might not be decomposed.

In any case, spray the still warm plate with ammonium molybdate solution (solution II) Then spray the still wet plate with tin (II) chloride solution (solution III)

Results: Phosphates appear as blue to blue-green spots. Polyphosphates can also be detected by dipping the

plates in a solution of ammonium molybdate (1g) dissolved in water (8ml) and perchloric

acid (3ml, ca. 70%),

filled up to 100ml with acetone. Then phosphates appear as yellow-green spots on a blue background. Also see

Molybdenum blue reaction according to Dittmer and Lester.

Aniline phthalate(邻苯二甲酸胺)

For the detection of reducing sugars

Dry the developed chromatogram

Spray with 0.93g aniline and 1.66g o-phthalic acid dissolved in 100ml n-butanol saturated with water.

Briefly dry with hot air, then heat to 105 C for 10 minutes

Results: Substance spots show different colors on an almost colorless background. Some spots give

fluorescence at 365nm.

p-Anisaldehyde – sulfuric acid(对甲氧基苯甲醛-硫酸)

For detection of phenols, sugars, steroids, and terpenes

Spray with a solution of freshly prepared 0.5ml p-anisaldehyde in 50ml glacial acetic acid and 1ml 97% sulfuric acid. and heat to 105°C until maximum visualization of spots. The background might be brightened by water vapor.

Results: Lichen constituents, phenols, terpenes, sugars, and steroids turn violet, blue, red, grey or green.

For detection of sugars

Spray with a solution of freshly prepared 1ml p-anisaldehyde, 1ml 97% sulfuric acid in 18ml ethanol and heat at110°C.

Results: Sugar phenylhydrazones produce green-yellow spots in 3 min. Sugars will produce blue, green, violet

spots in 10min. Also detects d igitalis glycosides.

p-Anisidine Hydrochloride

For detection of carbohydrates / sugars

Mix a solution of 3% p-anisidine hydrochloride in n-butanol

Spray and heat at 100°C for 2-10min.

Results: Aldohexoses are seen as green-brown spots, ketohexoses as yellow spots, aldopentoses as green

spots, and uronic acids as red spots.

Anisidine phthalate

For detection of carbohydrates and reducing sugars

Spray with a solution of 1.23 g p-anisidine and 1.66g phthalic acid in 100ml 95% ethanol. Results: Hexoses, green; pentoses, red-violet –sensitiv ity 0.5ug; methylpentoses,

yellow-green; uronic acids,

brown – sensitivity 0.1-0.2ug.

Antimony (III) chloride(三氯化锑)

For detection of flavonoids

Spray with a 10% solution of antimony (III) chloride in chloroform

Results: Fluorescing spots in long wavelength light (360nm).

Antimony (III) chloride

For detection of vitamins A & D, carotenoids, steroids, sapogenins, steroid glycosides,

terpenes

Spray with a solution of 25g antimony (III) chloride in 75ml chloroform (generally a

saturated solution of

antiomony (III) chloride in chloroform or carbon tetrachloride is used).

Heat 10min at 100C, view under long wavelength light (360nm).

Bromine / Carbon tetrachloride(四氯化碳)

For detection of organothiophosphorous pesticides

Place chromatogram in a chamber with a 10% bromine and tetrachloride without contact

with the liquid.

3

Bromocresol green

For detection of organic acids

Dip chromatogram in a solution of 0.1g bromocresol green in 500ml ethanol and 5ml 0.1M

NaOH

Results: Acids yield yellow spots on a blue background.

Bromthymol blue

For detection of lipids and phospholipids

Reagent: 0.1% bromthymol blue in 10% aqueous ethanol made just alkaline with NH4OH

Spray dried plate.

Results: Compounds above produce blue-green colors; sensitiv ity 0.1-1μg.

Chloranil reagent

For detection of phenols

Spray with a solution of 1% tetrachloro-p-benzoquinone in toluene

Chlorine / o-tolidine

For detection of of compounds forming chloroamines, e.g., urea derivatives, carbamated,

antibiotics

Solution I: 160mg o-tolidine in 30ml glacial acetic acid, filled to 500ml with distilled water,

plus 1g KI solution

Solution II: saturated solution of o-tolidine in 2% acetic acid/0.85% KI solution (1:1, v/v)

Procedure A

Place chromatogram 15-20min in a chlorine atmosphere (e.g., Potassium permanganate

+10% Hydrochloric

acid)

Leave 5 minutes at ambient temperature until the chlorine is evaporated completely (spray corner of plate to insure no blue color is seen, showing complete absence of

chlorine).

Spray with solution I

Procedure B

Spray with 2% potassium hypochlorite solution in water

Leave 1-1.5hr at ambient temperature

Spray with solution II

Copper sulfate / phosphoric acid(硫酸铜-磷酸)

Used as a charring reagent for polymer bound TLC plates (the newer hard layer plates) Spray with a solution of 10% copper (II) sulfate in 10% phosphoric acid

Heat 5-30min at 110°C

Results: View frequently (every 5-10min) to see if colored or fluorescent spots (at 254 and

360nm) can be seen.

Charring can be continued until spots are brown, grey or black.

Chromosulfuric acid

See under Potassium dichromate / sulfuric acid

DDQ Reagent (Dichlorodicyanobenzoquinone)

For detection of phenols

Spray with a solution of 2% 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in toluene

Dichlorofluorescein(二氯荧光黄)

For the detection of sweeteners saccharine & cyclamate

Spray with a 0.2% solution of dichlorofluorescein in 96% ethanol

Dry with warm air; if necessary, spray with water

View under 360nm UV light

Dichlorofluorescein / fluorescein sodium salt(荧光钠)

For detection of N-substituted barbiturates

Spray with a 0.1% ethanolic solution of dichlorofluorescein

Then spray with a 0.1% ethanolic solution of fluorescein sodium salt

2,6-Dichloroquinone -4- chloroimide

For detection of antioxidants, phenols, primary and secondary aliphatic amines,

secondary and tertiary aromatic

amines, aromatic hydrocarbons, pharmaceuticals, phenoxyacetic acid herbicides, etc Spray with a freshly prepared 0.5-2% solution of 2,6-dichloroquinone-4-chloroimide in

ethanol (reagent stable

for 3 weeks if refrigerated).

Heat 10min at 110 C; treat with ammonia vapor

p-Dimethylaminobenzaldehyde

For detection of sulfonamides

Spray with a solution of 1% p-dimethylaminobenzaldehyde in 5% hydrochloric acid; add

5% ethanol

Detects sulfonamides

p-Dimethylaminobenzaldehyde / hydrochloric acid reagent (Ehrlich’s reagent)

For detection of amines, indole derivatives

Spray with a solution of 1% p-dimethylaminobenzaldehyde in conc. hydrochloric

acid/methanol (2:2)

Heat plates for 20min at 50 C

2,4-Dinitrophenylhydrazine

For detection of aldehydes and ketones

Spray plate with solution of 0.4 g 2,4-DNPH in 100ml 2N hydrochloric acid, add 1ml

ethanol

Results: Yellow-red spots will be seen.

Diphenylamine(二苯胺)

For detection of glycosides, glycolipids

Reagent: 10ml 10% diphenylamine in ethanol, 100ml HCl and 80ml glacial acetic acid Spray lightly, cover plate with another glass plate, heat 30-40min at 110°C until positive

areas appear

Results: Glycolipids produce blue spots.

s-Diphenylcarbazone

For detection of barbiturates

Spary with a solution of 0.1% s-diphenylcarbazone in 95% ethanol

Results: Barbiturates will produce purple spots

2,2’-Diphenylpicrylhydrazyl

For detection of aldehydes and ketones

Reagent: dissolve 15mg of 2,2’-DPPH in 25ml chloroform

Spray, heat 5-10min at 110°C;

Results: Yellow spots on a purple background will be seen.

Dithizone(双硫腙)

For detection of heavy metal ions

Dissolve 20mg dithizone in 100ml acetone, store in a brown bottle in a refrigerator

Procedure:

Spray with dithizone solution

Spray with 25% ammonia solution

Dittmer and Lester

See Molybdenum blue

Dragendorff reagent

For detection of nitrogen compounds, alkaloids, antiarrhythmic drugs, surfactants Solution 1) 1.7g basic bismuth nitrate and 20g tartaric acid in 80ml water

Solution 2) 16 g potassium iodide in 40ml water

Stock solution (stable for several weeks in a refrigerator):

Mix equal volumes of solutions 1 and 2

Procedure:

Spray with a solution of 10g tartaric acid, 50ml water and 5ml stock solution Ethanolamine diphenylborate (flavone reagent according to Neu)

For detection of flavonoids

Spray with a 1% solution of ethanolamine diphenylborate in methanol

Spray with a 5% ethanolic solution of polyyethylene glycol for fluorescence stabilization Irradiate 2 minutes with intense 365nm UV light

View under 365nm UV light

Erhlich’s reagent

See p-Dimethylaminobenzaldehyde

Emerson reagent

See 4-aminoantipyrine/potassium hexa-cyanoferrate (III)

Fast Blue B reagent

For detection of cannabinoids, phenols, tanning agents, amines with can be coupled Spray with a solution of 0.5g Fast Blue B (tetraazotized di-o-anisidine) in acetone/water (9:1, v/v), always

prepared fresh

Then overspray with 0.1M sodium hydroxide solution

Results: Cannabinoids turn dark red/purple in color

Ferric Chloride / sulfuric acid

Used as a charring reagent for polymer bound TLC plates (the newer hard layer plates) Spray with a solution of 2g FeCl3 in 83ml n-butanol and 15ml conc. sulfuric acid.

Heat 5-30min at 110°C

Results: View frequently (every 5-10min) to see if colored or fluorescent spots (at 254 and 360nm) can be seen.

Charring can be continued until spots are brown, grey or black.

Flavone reagent according to Neu

See ethanolamine diphenyl borate

Fluorescamine

For detection of primary and secondary amines, peptides, sulfonamides, e.g., nitrosoamines after photolysis

Spray plate with a solution of 0.1mg/ml 4-phenyl-spiro[furan-2(3H),1-phthalan]-3,3-dione in acetone prepared

fresh daily

For stabilization of fluorescence at 366nm spray with 10g triethylamine, brought to 100ml with dichloromethane.

Fluorescent Indicator

For detection of compounds which absorb UV light

Some TLC plates when manufactured have an inorganic fluorescent indicator added to the slurry poured to

make the final plates. This type of indicator will not dissolve or elute off. They are activated at 254nm or 360nm

(see recommendations of the manufacturer for that type of plate).

Results: When activated the fluorescent indicator will turn a green or white (depending on the indicator added)

and the compounds appear as dark spots or shadows against this background. If viewing at other than the

activation wavelength, the compounds might also have some fluorescence of their own, so various colors

against a dark background would be seen.

Formaldehyde / sulfuric acid

For detection of alkaloids, aromatic hydrocarbons, e.g., antihypertensive drugs

Spray with a solution of 37% formaldehyde in conc. sulfuric acid (1:10) immediately after taking the plate from

the developing chamber. Heating is not necessary.

Results: various colored spots.

Formaldehyde / phosphoric acid

For detection of steroid alkaloids, steroid sapogenins and phenothiazine derivatives

6

Spray with a solution of 0.03g formaldehyde in 100ml of 85% phosphoric acid with stirring at room temperature.

The reagent is stable for several weeks.

Furfural / sulfuric acid

For detection of carbamate esters

Spray solution I: 1% solution of furfural in acetone

Spray solution II: 10% solution of sulfuric acid in acetone

Spray plate with I, then II.

Gentian Violet – Bromine

For detection of lipids

Spray 0.1% gentian violet (crystal violet) in methanol onto plate and place in a tank containing bromine vapor.

Results: lipids produce blue spots on a yellow background.

Gibb’s reagent

For detection of phenols. For further applications see 2,6-dichloroquinone-4-chloroimide Spray with a solution of 3% 2,6-dibromo-N-chloro-p-benzoquinone imine in toluene or methanol.

Hydroxylamine / iron (III) chloride

For detection of amides, lactones, carboxylic acid esters and anhydrides

Solution 1) Mix 1 vol part of 7g hydroxylammonium chloride in 100ml methanol w 1 vol part of a solution of 7.2 g

potassium hydroxide in 100ml methanol. Filter from precipitated potassium chloride. Solution 2) 2% solution of iron (III) chloride in 1% aqueous hydrochloride acid

Spray air dried plate first with solution 1, then with solution 2

Iodine containing compounds

Detection by decomposition under UV

Dry plates at 100 C

After cooling spray with a small amount of 50% acetic acid

Irradiate some minutes with unfiltered UV light.

Results: Iodine compounds show weakly violet to brown spots. The color can be enhanced by spraying with

10% acetic acid and irradiation with UV light (sudden appearance of blue spots).

Iodine vapor

Relatively unspecific universal reagent for many organic compounds

Charge chamber with some crystals of iodine

Place developed, dried chromatogram in iodine vapor

Results: spots turn tan-brown in color

Iodoplatinate

For detection of organic nitrogen compounds, alkaloids, e.g., cocaine metabolites

Spray with a freshly prepared mixture of 3ml hexachloroplatinic (IV) acid solution (10%) in 97ml/min water and

100ml aqueous potassium iodide solution.

Note - use 5% ethanol or methanol in water to prepare these solutions for the new

polymer bound TLC plates.

Iron (III) chloride / potassium hexacyanoferrate / sodium arsenate (according to Patterson & Clements)

For detection of iodine compounds, e..g., thyroid gland hormones

Solution I: 2.7% iron (III) chloride hexahydrate in 2N hydrochloric acid

Solution II: 3.5% potassium hexacyanoferrate in water

Solution III: dissolve 3.8g arsenic trioxide in 25ml 2N sodium hydroxide solution heating slightly, cool to 5 C, and

add 50ml 2N sulfuric acid, fill to 200ml with water

Immediately before use mix 5ml solution I, 5ml solution II and 1ml solution III.

Spray onto the dry layer and dry carefully (temp below 50 C)

Cover with glass plate and leave 15min in the dark

Results: Iodine containing compound show light blue spots on a yellowish background. Lead tetraacetate / 2,7-dichlorofluorescein

For detection of vicinal diols, glycosides and phenols, e.g., sugar acids

Solution I: 2% (w/v) lead tetraacetate in glacial acetic acid

Solution II: 1% (w/v) 2,7-dichlorofluorescein in ethanol

Mix 5ml of each solution 1 and 2, fill to 200ml with dry toluene. This reagent solution is stable for only about 2

hours.

Manganese / salicylaldehyde

For detection of organothiophosphorus pesticides

Solution I: dissolve 100mg manganese chloride (MnCl2.4H2O) in 100ml 80% alcohol Solution II: dissolve 1.3g 2-hydrozine quinoline in the lowest possible volume of hot ethanol. Dissolve 1 g

salicyaldehyde in 5ml ethanol and add 1-2 drops glacial acetic acid. Combine both solutions and reflux 30

minutes. The crystals of salicyl-2-aldehyde –2-quinolinehydrazone precipitated during the cooling are

recrystallized from ethanol. For solution dissolve 50mg of the salicylate derivative in 100ml ethanol

Spray with a mixture of equal volumes of solutions 1 and 2.

Mandelin’s reagent

See Vanadium(V) / sulfuric acid

Mercury (II) chloride / diphenylcarbazone

For detection of barbiturates

Solution I: 2% ethanolic mercury (II) chloride

Solution II: 0.2% ethanolic diphenlycarbazone

Mix freshly before use in equal parts

Results: Pink spots on a violet background

Mercury (II) chloride / dithizone

For detection of barbiturates

Spray with a freshly prepared 1:1 mixture of 1-2% mercury (II) chloride in ethanol and 0.1-0.2% dithizone in

ethanol.

View under 360nm UV light

4-Methoxybenzaldehyde / sulfuric acid / ethanol

For detection erythromycin and metabolites

Spray with 4-methocybenzaldehyde/sulfuric acid/ethanol (1:1:9)

Heat 1 minute at 100 C

Methyl yellow

For detection of chlorinated insecticides and antimicrobial compounds

Spray dried plate with a solution of 0.1g methyl yellow (N,N-dimethyl-4-phenylazoaniline) in 70ml ethanol, add

25ml water and fill to 100ml with ethanol.

Dry at ambient temperature

Irradiate 5 min with UV light without a filter

Results: Red spots on a yellow background

Molybdatophosphoric acid

See under Phosphomolybdic acid

Molybdenum blue reaction according to Dittmer and Lester

For detection of phospholipids and phosphoric acid derivatives

Solution I: Boil 40.11g MoO3 in 1 liter 25N sulfuric acid for 3-4 hours until the molybdenum oxide is completely

dissolved. Let the light yellow solution slowly cool to ambient temperature overnight. The solution will turn light

blue.

Solution II: Boil 1.78 g molybdenum powder and 500ml of solution I for 15min, cool and decant from the

remaining residue.

8

For preparation of the spray reagent, add equal volumes of solutions I and II to 4.5 volume parts water. A dark

green solution is formed.

Solutions I and II are stable for several months when stored in the dark. The spray reagent has to be prepared

weekly.

Ninhydrin

For detection of amino acids, amines, amino sugars.

Spray with a solution of 0.2g ninhydrin in 100ml ethanol and heat to 110 C until spots appear.

Results: reddish spots appear

Ninhydrin / cadmium acetate

For detection of amino acids and heterocyclic amines

Dissolve 1g ninhydrin and 2.5g cadmium acetate in 10ml glacial acetic acid and fill to 500ml with ethanol.

Spray and heat 20min at 120 C

Results: Red, pink, or purple spots are seen.

Ninhydrin / pyridine / glacial acetic acid

For detection of peptides

Spray with a 1% ninhydrin in pyridine/glacial acetic acid (5:1, v/v)

Heat 5 min at 100 C

Nitric acid / ethanol

For detection of amines and alkaloids

Spray with a solution of 50 drops 65% nitric acid in 100ml ethanol (higher acid concentrations are also possible).

If necessary, heat to 120 C for some time.

Orcinol (Bials reagent)

For detection of glycosides, glycolipids

Reagent: dissolve 0.1g orcinol in 40.7ml conc. HCl, add 1ml 1% ferric (111) chloride, and dilute to 10ml

Spray and heat at 80°C for 90 minutes.

Results: Glycolipids produce violet spots.

Patterson and Clements

See under Iron (III) chloride/potassium hexacyanoferrate/sodium arsenate

Paraffin oil

For enhancement of fluorescence spots – more stable and greater intensity

1% paraffin oil in hexane

Spray evenly over the TLC plate

Results: spots should be more stable (no fading with time) for scanning and are of greater intensity

m-Phenylenediamine

For detection of reducing sugars

Spray with a solution of 3.6g m-phenylenediamine dihydrochloride in 100ml 70% ethanol and heat briefly at

Results: Intensely fluorescence colors in UV light (wavelength not specified, so check 254 and 366nm).

o-Phenylenediamine – trichloroacetic acid

For detection of alpha-keto acids

Spray with a solution of 0.05g 1,2-phenylenediamine in 100ml 10% aqueous trichloroactic acid and heat plate at

100C for no more than 2 minutes.

Results: Green fluorescence spots in long wavelength UV light.

p-Phenylenediamine – phthalic acid

For detection of conjugated 3-ketosteroids

9

Spray with a solution of 0.9 p-phenylenediamine and 1.6g phthalic acid in 100ml 1-butanol saturated with water

and heat plate at 100-110°C

Results: Yellow to orange spots

Phenylhydrazine sulfonate

For detection of some antimicrobial compounds

Solution I: dissolve 3.5g phenylhydrazine 4-sulfonic acid hemihydrate in 10ml water and 20ml 1N NaOH solution

Solution II: mix 30ml 1N sodium hydroxide solution with 40ml acetone

The spray reagents have to be prepared fresh each time.

Procedure:

Wet chromatogram evenly with spray solution 1

After air drying the plate, shake spray solution 2 and spray plate.

Phosphoric acid

For detection of sterols, steroids, and bile acids

Spray heavily until the layer appears transparent with a solution of 85% phosphoric acid with water (1:1, v/v)

Then heat 10-15minutes at 120°C

Results: Sterols, steroids and bile acids and bile acids produce various colors under visible and UV light.

Phosphoric acid – bromine

For detection of digitalis glycosides

Spray solution I: 10% aqueous phosphoric acid solution

Spray solution II: Mix 2ml saturated aqueous potassium bromide, 2ml saturated solution aqueous potassium

bromate and 2ml 25% hydrochloric acid.

Procedure: Spray plate with I and heat 12 min at 120°C.

Results: Digitalis glycosides of the series B, D, and E show blue fluorescence in long wavelength UV light

Procedure continued: Heat the plate again at 120°C and spray lightly with II

Results: Glycosides of the series A show orange, of the series C show grey-green to grey-blue fluorescence in

Phosphomolydbic acid

For detection of reducing substances, e.g, alcohols, bile acids, lipids, fatty acids, steroids Also used as a charring reagent for polymer bound TLC plates (the newer hard layer plates) Spray with a solution of 250mg molybdatophosphoric acid in 50ml ethanol

Heat to 120 C until spots appear (oven or heat gun)

If necessary, treat with ammonia vapors to remove some background coloration.

The reagent solution is stable for only 10 days even in the dark.

Results when using as a charring reagent: View frequently (every 5-10min) to see if colored or fluorescent spots

(at 254 and 360nm) can be seen. Charring can be continued until spots are brown, grey or black.

Phosphotungstic acid

For detection of cholesterol and its esters, reducing compounds, lipids, sterols, and steroids

Spray with 20% phosphotungstic acid in ethanol, heat at 110°C for 5-15min or until maximum visualization of the

spots occurs

Results: Cholesterol, esters will produce red spots.

Pinacryptol yellow

For detection of sweetners, surfactants, alkyl- and ary lsulfonic acids

Dissolve 100mg pinacryptol yellow in 100ml hot water or ethanol (or some combination for polymer bound

plates)

Spray with reagent solution

Results: Yellow to orange fluorescence spots under long wavelength UV light (366nm) Potassium dichromate / sulfuric acid (chromosulfuric acid) - see below

10

Potassium permanganate / sulfuric acid – see below

Rhodamine B

For detection of a wide variety of compounds

Dry the developed chromatogram and spray with 0.025-0.25% ethanolic rhodamine B reagent.

Results: In most cases red-violet zones with an intense fluorescence at 365nm develop on a pink background.

RP phases are less suited, because in this case the environment of the spots also forms an intense color. By

placing the sprayed chromatograms into an ammonia atmosphere, the detection sensitivity can be improved.

Rhodamine 6 G

For detection of lipids

Spray plate with a solution of 1mg rhodamine 6 G in 100ml acetone

Inspect at long wavelength UV.

Silver nitrate / hydrogen peroxide

For detection of halogenated hydrocarbons

Spray plate with a solution of 0.1g silver nitrate in 1ml water, add 10ml 2-phenoxyethanol, fill to 200ml with

acetone and add 1 drop hydrogen peroxide (30% solution)

Irradiate with unfiltered UV light until optimal contrast is obtained. For alumina plates, about 50 minutes, for

silica gel plates about 15 minutes

Results: dark spots are formed.

Luckow [Fensenius Z. Anal. Chem., 294, 288, (1979)] uses this combination without the addition of hydrogen

peroxide for the detection of pesticide ioxynil (3,5-diiodo-4-hydroxybenzonitrile). Sodium azide

For detection of antibiotics (penicillins and cephlosporins)

Solution I: 0.5% solution of soluble starch

Solution II: 3.5% sodium azide in 0.1N iodine solution

Procedure: spray with 1), dry, spray with 2)

Results: Detects penicillin, sensitivity 0.2μg. Penicillin and penicilloic acids are also detected by starch-iodineiodine

reagents, as are cephalosporins.

Sodium 1,2-napthaquinone-4-sulfonate (NZS reagent)

For detection of thiazide drugs, basic drugs with primary amino groups

Solution I: 0.1N NaOH

Solution II: saturated solution of reagent in 1:1 ethanol: water

Spray with I, then II.

Results: Thiazide drugs appear as orange spots within 15min; basic drugs with primary amino groups also react

but barbiturates do not.

Sodium nitrite / hydrochloric acid

For detection of indoles and thiazoles

Spray plate with a freshly made solution of 1g sodium nitrite in 100ml hydrochloric acid, 1mol/L and heat at

100°C.

Results: Indoles turn red and thiazole derivatives turn light green.

Sodium nitroprusside / hydrogen peroxide

For detection of guanidine, urea, thiourea and derivatives, creatine and creatinine.

Spray with a solution made up of 2ml 5% aqueous sodium nitroprusside, 1ml 10% aqueous sodium hydroxide

and 5ml 3% aqueous hydrogen peroxide and dilute with 15ml water. This solution can be stored several days in

the refrigerator.

Sodium nitroprussate / potassium hexacyanoferrate (III)

For the detection of aliphatic nitrogen compounds, cyanamide, guanidine, urea, thiourea and derivatives,

creatine, and creatinine.

12

Spray solution III – for digitalis glycosides – dissolve 3.3g trichloroacetic acid in 10ml chloroform and add 1-2

drops hydrogen peroxide.

After apply ing the appropriate solution, heat 5-10min at 120°C.

Inspect the spots in day light and in long wavelength UV light.

Trifluoroacetic acid

For detection of steroids

Spray with a solution of 1% trifluoroacetic acid in chloroform and heat 5min at 120°C Triethanolamine

For enhancement of fluorescence species

20% solution of reagent in isopropanol

Tungstophosphoric acid

See under Phosphotungstic Acid

Ultraviolet Light - fluorescence

For detection of various compounds which have native fluorescence.

With a plate containing a fluorescent indicator (F254), examine the dried chromatogram under 360nm UVlight.

With a TLC plate containing no fluorescent indicator, examine the dried chromatogram under both 254 and

360nm UV light.

Ultraviolet Light - quenching

For detection of various compounds which absorb 254nm UV light; quenching of TLC plate fluorescence.

Examine a fluorescent indicator (F254) containing plate after dried, under 254nm UV light. Compounds absorbing this wavelength light will appear as dark spots against a green or white fluorescence

caused by the UV activation of the fluorescent indicator in the plate.

Urea / hydrochloric acid

For detection of sugars

Spray with a solution of 5g urea in 20ml 2M hydrochloric acid, with 100ml ethanol added and heat to 100°C.

Results: Ketoses and oligosaccharides containing ketoses turn blue.

Vanadium (V) / sulfuric acid

For detection of carbohydrates, glycols, reducing carboxylic acids, steroids, antioxidants, vitamins, phenols,

aromatic amines, antihistamines

a) Ammonium monovanadate (ammonium metavanadate) /sulfuric acid reagent

Spray with a solution of 1.2g ammonium monovanadate in 95ml water and 5ml conc. sulfuric acid or for beta

blockers: spray with saturated solution of ammonium monovanadate in conc. sulfuric acid.

b) Vanadium pentoxide / sulfuric acid reagent

Spray with a solution of 1.82g vanadium pentoxide in 30ml 1M sodium carbonate, sonicate to achieve

complete dissolution, after cooling add 46ml 2.5M sulfuric acid and fill to 100ml with acetonitrile.

Vanillin / potassium hydroxide

For detection of amines and amino acids

Spray with a solution of 1g vanillin in 50ml 2-propanol and dry 10min at 110 C

Then spray with 1ml 1M potassium hydroxide solution filled up to 100ml with ethanol and dry 10 min at 110 C

View at 365nm UV

Results: After spraying with a) ornithine will be seen as a bright green-yellow fluorescence, lysine as a greenyellow

fluorescence. After spraying with b) ornithine will show a salmon color that will fade; proline,

hydroxyproline, pipecolinic (pipecolic) acid and sarcosine will turn red after a few hours. Glycine will produce a

green brown spot, and other amino acids will turn faint brown.

Vanillin / phosphoric acid

Used as a charring reagent for polymer bound TLC plates (the newer hard layer plates) Spray plate with 1g vanillin in 100ml 50% aqueous H3PO4

13

Heat 5-30min at 110°C.

Results: View frequently (every 5-10min) to see if colored or fluorescent spots (at 254 and 360nm) can be seen.

Charring can be continued until spots are brown, grey or black.

Vanillin / sulfuric acid - see immediately below

The charring visualization reagents given below can only be used with glass TLC

plates in

which a G (gypsum) binder has been used in the formulation to hold the silica gel on

the plate:

Potassium dichromate / sulfuric acid (chromosulfuric acid)

Universal visualization reagent for organic compounds (e.g., alcohols, also for bile acids, lipids) – note: do not

use this reagent on polymer bound TLC plates since it will char the binder; use only with G

(gypsum) binder

plates.

Spray with a solution of 5g potassium dichromate in 100ml conc. Sulfuric acid.

If necessary heat plate to 150 C

Results: Brown, grey, or black spots result

Potassium permanganate / sulfuric acid

Universal reagent for organic compounds, e.g., fatty acid derivatives

Note: Do not use this reagent on polymer bound TLC plates since it will char the binder; use only with G

(gypsum) binder plates.

Spray with a solution of 1.6% potassium permanganate in conc. sulfuric acid (make this solution very carefully,

and slowly to prevent any accidents).

Heat plate for 15-20min at 180 C

Vanillin / sulfuric acid

For detection of steroids, Note, this reagent can only be used with G (gypsum) binder plates since it will char the

polymer binders in the harder layer plates.

Spray with a 1% solution of vanillin in conc. sulfuric acid and at 120 C until maximum color formation.

Another formulation of this reagent: 0.5g vanillin in 100ml sulfuric acid/ethanol (40:10). TLC Texts with Visualization Reagent Information:

Thin Layer Chromatography, 2nd edition, E. Stahl, ed, Springer-Verlag, NY, 1969

TLC Reagents & Detection Methods –Physical & Chemical Detection Methods: Fundamentals, Reagents,I, Vol

1a, H. Jork, W. Funk, W. Fishcer, & H. Wimmer, Wiley, NY, 1990

Practice of Thin Layer Chromatography, 3rd edition, J.C. Touchstone, Wiley-Interscience, NY, 1992

TLC Reagents & Detection Methods – Physical & Chemical Detection Methods: Activation Reactions, Reagent

Sequences, Reagents, II, Vo l 1b, H. Jork, W. Funk, W. Fishcer, & H. Wimmer, Wiley, NY, 1994

Important Notes – Please read carefully :

1) When using the older texts, if they suggest putting the components into benzene, always substitute

toluene since it is much less toxic. Likewise, as mentioned above, if the components are added to pure

water, these solutions cannot penetrate well into the polymer bound layers (hard layers) now sold.

Substitute 5% methanol in water or 5% ethanol in water as the makeup solvent in these instances.

2) In past years various visualization reagents were made up with benzidine. It had been used for the

detection of terpene aldehydes, flavoinoids, carbohydrates and phenols. This reagent is no

展开剂选择

如何选择适当的展开剂 选择适当的展开剂是首要任务.一般常用溶剂按照极性从小到大的顺序排列大概为:石油迷<己烷<苯<乙醚 Petroleumether/Ethylacetate,petroleumether/Acetone,Petroleumether/Ether, Petroleumether/CH2Cl2, ethylacetate/MeOH,CHCl3/ethylacetate 展开剂的比例要靠尝试.一般根据文献中报道的该类化合物用什么样的展开剂,就首先尝试使用该类展开剂,然后不断尝试比例,直到找到一个分离效果好的展开剂。展开剂的选择条件:①对的所需成分有良好的溶解性;②可使成分间分开;③待测组分的Rf在0.2~0.8之间,定量测定在0.3~0.5之间;④不与待测组分或吸附剂发生化学反应;⑤沸点适中,黏度较小;⑥展开后组分斑点圆且集中;⑦混合溶剂最好用新鲜配制。 一般来说,弱极性溶剂体系的基本两相由正己烷和水组成,再根据需要加入甲醇、乙醇,乙酸乙酯来调节溶剂系统的极性,以达到好的分离效果,适合于生物碱、黄酮、萜类等的分离;中等极性的溶剂体系由氯仿和水基本两相组成,由甲醇、乙醇,乙酸乙酯等来调节,适合于蒽醌、香豆素,以及一些极性较大的木脂素和萜类的分离;强极性溶剂,由正丁醇和水组成,也靠甲醇、乙醇,乙酸乙酯等来调节,适合于极性很大的生物碱类化合物的分离。 很多时候,展开剂的选择要靠自己不断变换展开剂的组成来达到最佳效果。我们在实验中,为了实现一个配体与其他杂质有效分离,曾经尝试了很多种的溶剂组合,最后才找到石油醚—EtOAc—HCOOH(5.5:3.5:0.1)混合溶剂。一般把两种溶剂混合时,采用高极性/低极性的体积比为1/3的混合溶剂,如果有分开的迹象,再调整比例(或者加入第三种溶剂),达到最佳效果;如果没有分开的迹象(斑点较“拖”),最好是换溶剂。对于在硅胶中这种酸性物质上易分解的物质,在展开剂里往往加一点点三乙胺,氨水,吡啶等碱性物质来中和硅胶的酸性。(选择所添加的碱性物质,还必须考虑容易从产品中除去,氨水无疑是较好的选择。)分离效果的好坏和所用硅胶和溶剂的质量很有关系:不同厂家生产的硅胶可能含水量以及颗粒的粗细程度,酸性强弱不同,从而导致产品在某个厂家的硅胶中分离效果很好,但在另一个厂家的就不行。溶剂的含水量和杂质含量对分离效果都有明显的影响。温度,湿度对分离效果影响也很明显,在实验中我们发现有时同一展开条件,上下午的Rf截然不同. 展开剂的选择主要根据样品的极性、溶解度和吸附剂的活性等因素来考虑 在进行薄层层析时,首先应该知道未知化学成分的类型,其极性的大致归属,从提取液或从色谱柱的流动相极性可知,另外某样品里含多种化学成分先按极性不同大致分,然后细分,对于分离未知的化学物质,展开剂的选择也是一个摸索的过程,不应该仅仅从展开剂考虑,多因素综合衡量! 溶剂:层析过程中溶剂的选择,对组分分离关系极大。在柱层析时所用的溶剂(单一剂或混合溶剂)习惯上称洗脱剂,用于薄层或纸层析时常称展开剂。洗脱剂的选择,须根据被分离物质与所选用的吸附剂性质这两者结合起来加以考虑在用极性吸附剂进行层析时,当被分离物质为弱极性物质,一般选用弱极性溶剂为洗脱剂;被分离物质为强极性成分,则须选用极性溶剂为洗脱剂。如果对某一极性物质用吸附性较弱的吸附剂(如以硅藻土或滑石粉代替硅胶),则洗脱剂的极性亦须相应降低。 在柱层操作时,被分离样品在加样时可采用于法,亦可选一适宜的溶剂将样品溶解后加

怎样选择展开剂

【分享】怎样选择展开剂 ★ ★ 小木虫(金币+1):奖励一下,鼓励发有价值的话题 秋天白云(金币+1):谢谢分享! 2010-08-23 11:27:22 枫叶子2006:编辑内容 2010-11-30 22:58 xiazanwen:编辑内容 2011-07-12 15:32 展开剂的选择 最近刚进实验室,用TLC对反应进行检测,但是关于展开剂的资料不多,我们实验室大多就是两个体系:石油醚/乙酸乙酯,氯仿/甲醇,其他的就很少了,所以我下决心把这个实验室比较常用的技术搞清楚。 一种简单的办法是根据你产物的溶解性选择一种极性最强的溶剂学(如醇类,乙氰等),再根据你实际展开的情况慢慢加入极性弱的溶剂(如四氯化碳、石油醚、二氯甲烷等)调节体系的极性。以得到最好的展开效果。把我的祖传秘方告诉你吧 PE(60-90) EtAc/PE=1:2 EtAc/PE/AcOH=15:5:1 EtAc/AcOH/n-Butanol/H2O=2:1:1:1 8年来我用这四种体系,没有出现过什么问题我一直在用的是乙酸乙酯:环已烷,不断调节比例,直到有满意的Rf值,有拖尾时可能要加酸或碱,我一般乙酸和三乙胺。我用了好几年了,都还好。不妨一试! 氨基酸都有专用的展开剂,常用丁醇和水,再加酸碱选择展开剂一般要用混合溶剂:一般要有一种对所要展开样品溶解度较大的溶剂,视样品的极性,再选用相应的体系。极性小

的用乙酸乙酯:石油醚系统极性较大的用甲醇:氯仿系统极性大的用甲醇:水:正丁醇:醋酸系统 拖尾可以加入少量氨水或冰醋酸(应该交好)甲醇:氯仿对于胺类比较好我常用的展开剂有:氯仿/甲醇;环已烷/丙酮;醋酸乙酯/石油醚;甲醇/吡啶/水;等.本人用过的展开系统中,苯-丙酮用的最多,通过调节不同比例可以得到较好的效果俺的: EtOAc/Hexanes Ch2Cl2(EtOAc)/MeOH, 0-1% TEA or NH3 极性乙酸乙酯和非极性的石油醚按不同比例混合对一般的都能适应人民卫生出版社的《分析化学》(下册)有专门的介绍,很详细。我一般用乙酸乙酯和石油醚配成不同比例的混合溶剂。实验时调整至Rf=0.3--------0.5我们做的氨基酸,用的都是丁醇:醋酸:水二氯甲烷:甲醇,调节不同的配比基本解决大多数问题. 用二氯甲烷与甲醇体系非常有用,只要调整好比例。展开剂的使用一看自己的喜爱;二看产品特点。我多用氯仿/甲醇或石油醚/乙酸乙酯!主要是调节比例!掌握了几种展开剂的比例和极性,处理起来就容易多了!用乙酸乙酯/正己烷,必要时加醋酸或三乙胺。 我常用:正己烷+乙酸乙酯;氯仿+甲醇(常为10:1);石油醚+丙酮。拖尾的话常滴加两三滴三乙胺了事。过柱最好不用三乙胺,可以添加1%的二乙胺,这样有利于馏分收集后的浓缩和送谱。如果用三乙胺,在油泵上抽数个小时,送nmr仍可见三乙胺的残留。同理,可能的情况下最好用甲酸代替乙酸。我们这里都是用石油醚和乙酸乙酯,然后不断的调比例,效果不错。我们通常用石油醚,二氯甲烷,乙酸乙酯。不断的点板看,但夏天蒸出来后极性有些小。拖尾不要紧,改溶剂过柱子就可以。首先,选一种易溶你产品的一种不溶的;接着,按照溶:不溶=1:2的比例配比,看一下其展开的情况; 再次,太高就减少溶的比例,太低就减少不溶的比例!这样正常情况下时可行的!祝大家好运!

实验室中常用抗凝剂

实验室中常用的抗凝剂有肝素、乙二胺四乙酸盐(EDTA盐)、枸橼酸盐、草酸盐等4种,实际应用中要根据不同的需要进行选择,才能获得理想的效果。现将它们的应用特点分述如下: 一、肝素 抗凝是用于血液化学成分检测的首选抗凝剂。肝素是一种含有硫酸基团的粘多糖,是分散相物质平均分子质量为15000。其抗凝原理主要是通过与抗凝血酶Ⅲ结合引起抗凝血酶Ⅲ构型发生变化,加速凝血酶-凝血酶复合体形成而产生抗凝作用。此外,肝素还能借助血浆辅助因子(肝素辅助因子Ⅱ)来抑制凝血酶。常用肝素抗凝剂是肝素的钠、钾、锂、铵盐,其中以肝素锂最好,但其价格较贵,钠、钾盐会增加血液中的钠、钾含量,铵盐会增加尿素氮的含量。通常用肝素抗凝的剂量为10.0~12.5 IU/ml血液。 肝素对血液成分干扰较少,不影响红细胞体积,不引起溶血,适用于做红细胞渗透性试验、血气、血浆渗透量、红细胞压积及普通生化测定。但肝素具有抗凝血酶作用,不适合做血凝试验。另外,肝素过量可引起白细胞聚集和血小板减少,所以不适合做白细胞分类和血小板计数,更不能用于止血检验。此外,肝素抗凝血不能用于制作血涂片,因为Wright染色后出现深蓝色背景,影响显微镜减产。肝素抗凝血应于短时间内使用,否则放置过久血液又可凝固。 二、乙二胺四乙酸盐(EDTA盐) EDTA能与血液中Ca2+结合成螯合物,凝血过程被阻断,血液不能发生凝固。EDTA盐有钾、钠、锂盐,国际血液学标准化委员会推荐使用的是EDTA-K2,其溶解度最高,抗凝速度最快。EDTA盐通常配成质量分数是15%的水溶液,每ml 血液加1.2mgEDTA,即每5ml血液加0.04ml 15%EDTA溶液。EDTA盐可在100℃下干燥,抗凝作用不变。

展开剂的选择

1 用薄层色谱发分离两极性组分,其Rf 的值分别为和,可采取哪种措施改善分离效果 A换用极性较弱的展开剂 B换用活性更强的吸附剂 C换用极性较强的展开剂 D换用活性较差的吸附剂 我选的是C,答案是A。为什么 B ,D 两个选项怎么考虑 解答: 由题意知,Rf 1=,Rf 2 =,这两个组分的Rf值非常接近,即ΔRf=Rf 1 -Rf 2 =值 很小。故要改善分离效果,需要增加ΔRf值。 从理论上讲,改变固定相或展开剂(流动相)的种类都可以改变ΔRf值的大小,但由于薄层色谱的固定相种类有限,而可以用作展开剂的有机溶剂的种类却很多且方便易得,因此通常情况下优先考虑改变展开剂的种类来调整展开剂的极性,以改善分离效果。对于极性组分,换用极性相对较弱的展开剂,此时的展开剂的洗脱能力会下降,则展开的时间也会增加,这样能够增加ΔRf值,从而改善分离效果。换用活性相对较强的吸附剂同样也能使展开剂的洗脱能力下降,但如果吸附剂的活性过强会导致吸附太牢固而无法洗脱。 因此,此题的最佳答案应为A。

(三)吸附薄层色谱条件的选择 根据被测组分的极性大,选择吸附剂的活度要小,流动相极性要大;被测组分的极性小,选择吸附剂的活度要大,流动相极性要小。 1.被分离物质的极性与结构的关系 (1)基本母核相同,基团极性愈大,分子极性愈强;极性基团数目增加,分子极性增强。常见的取代基极性大小顺序:烷烃<烯烃<醚类<硝基化合物<二甲胺<脂类<酮类<醛类<硫醇<胺类<酰胺<醇类<酚类<羧酸类。 (2)分子双键愈多,共轭度愈大,吸附性愈大。 (3)空间排列影响极性,如能产生分子内氢键的分子极性下降。 2.吸附剂的活度选择被分离物质的极性大,吸附剂活度要小,以免吸附太牢,不易洗脱;被分离物质的极性小,则吸附剂的活度要大,以免不被吸附,而无法分离。可改变板活化温度和时间来控制吸附剂的活度。 单一溶剂的极性顺序:石油醚<环己烷<二硫化碳<四氯化碳<三氯乙烷<苯、甲苯<二氯甲烷<氯仿<乙醚<乙酸乙酯<丙酮 <正丙醇<乙醇<甲醇<吡啶<酸<水。 4.混合溶剂选择的一般规则先用单一的中等极性展开剂试验,得出合适的极性。再改用二元展开剂,调节比例达到预期的极性,得到混合展开剂。目的是通过混合展开剂的极性和溶剂的强度,使各组分具有适宜的Rf值,从而达到良好的分离效率。

血液抗凝剂的特点及应用

实验室常用血液抗凝剂的特点及应用 在实验室检验中,有许多检测项目的血液标本是需要抗凝才可以检测的。而抗凝剂种类较多,实际应用中要根据不同的需要进行选择,才能获得理想的效果。实验室中常用的抗凝剂有肝素、乙二胺四乙酸盐(EDTA盐)、枸橼酸盐、草酸盐等4种,现将它们的特点及应用分别叙述如下: 一、肝素 抗凝是用于血液化学成分检测的首选抗凝剂。肝素是一种含有硫酸基团的粘多糖,是分散相物质平均分子质量为15000。其抗凝原理主要是通过与抗凝血酶Ⅲ结合引起抗凝血酶Ⅲ构型发生变化,加速凝血酶-凝血酶复合体形成而产生抗凝作用。此外,肝素还能借助血浆辅助因子(肝素辅助因子Ⅱ)来抑制凝血酶。常用肝素抗凝剂是肝素的钠、钾、锂、铵盐,其中以肝素锂最好,但其价格较贵,钠、钾盐会增加血液中的钠、钾含量,铵盐会增加尿素氮的含量。通常用肝素抗凝的剂量为10.0~12.5 IU/ml血液。 肝素对血液成分干扰较少,不影响红细胞体积,不引起溶血,适用于做红细胞渗透性试验、血气、血浆渗透量、红细胞压积及普通生化测定。但肝素具有抗凝血酶作用,不适合做血凝试验。另外,肝素过量可引起白细胞聚集和血小板减少,所以不适合做白细胞分类和血小板计数,更不能用于止血检验。此外,肝素抗凝血不能用于制作血涂片,因为Wright染色后出现深蓝色背景,影响显微镜减产。肝素抗凝血应于短时间内使用,否则放置过久血液又可凝固。 二、乙二胺四乙酸盐(EDTA盐) EDTA能与血液中Ca2+结合成螯合物,凝血过程被阻断,血液不能发生凝固。EDTA盐有钾、钠、锂盐,国际血液学标准化委员会推荐使用的是EDTA-K2,其溶解度最高,抗凝速度最快。EDTA盐通常配成质量分数是15%的水溶液,每ml血液加1.2mgEDTA,即每5ml血液加0.04ml 15%EDTA溶液。EDTA盐可在100℃下干燥,抗凝作用不变。 此抗凝剂不影响白细胞计数及大小,对红细胞形态影响最小,并且可以抑制血小板的聚集,适用于一般血液学检测。但如果抗凝剂浓度过高,渗透压上升,会造成细胞皱缩。EDTA溶液pH与盐类关系较大,低pH可使细胞膨胀。EDTA-K2可使红细胞体积轻度膨胀,采血后短时间内平均血小板体积非常不稳定半小时后趋于稳定。EDTA-K2使 Ca2+、Mg2+下降,同时使肌酸激酶、碱性磷酸酶降低,EDTA-K2的最佳浓度为1.5mg/ml血液,如果血少,中性粒细胞会肿胀分叶消失,血小板会肿胀、崩解,产生正常血小板的碎片,使分析结果产生错误。EDTA由于能抑制或干涉纤维蛋白凝块形成时纤维蛋白单体的聚合,不适于血凝和血小板功能检测,也不适用于钙、钾、钠及含氮物质的测定。此外,EDTA能影响某些酶的活性和抑制红斑狼疮因子,故不适合制作组化染色和检查红斑狼疮细胞的血涂片。 三、枸橼酸盐 枸橼酸盐主要是枸橼酸钠,其抗凝原理是能与血液中的Ca2+结合形成螯合物,使Ca2+失去凝血功能,凝血过程被阻断,从而阻止血液凝固。枸橼酸钠有Na3C6H5O7·2H2O和2Na3C6H5O7·11H2O两种晶体,通常用前者配成3.8%或3.2%的水溶液,与血液按照1:9体积混合。 大部分凝血试验都可用枸橼酸钠抗凝,它有助于Ⅴ因子和Ⅷ因子的稳定,并且对平均血小板体积及其他凝血因子影响较小,可用于血小板功能分析。枸橼酸钠细胞毒性较小,也是输血中血液保养液的成分之一。但是,枸橼酸钠6mg才能抗凝1ml血液,碱性强,不适用于血液化验和生化测验。 四、草酸盐 草酸盐也是常用的抗凝剂,优点是溶解度大,作用原理是溶解后解离的草酸根与标本中的Ca2+形成草酸钙沉淀,使Ca2+失去凝血功能,凝血过程被阻断。常用的草酸盐抗凝剂种类有草酸钠、草酸钾和草酸铵,草酸钠的常用浓度为O.1 mol/L,与血液按1:9比例使用。但是,高浓度k+或Na+易使血细胞脱水皱缩,而草酸铵则可使血细胞膨胀,故测定血细胞比容时用草酸铵与草酸钾或草酸钠两者适当比例混合的抗凝剂,恰好不影响红细胞的形态和体积。常用于血液生化测定,但不适用于K+、Ca 2+的测定。由于生成草酸钙沉淀,红细胞会出现锯齿状,白细胞出现空泡,淋巴细胞及单核细胞会变形,不宜做血片检查。草酸盐可使血小板聚集,并影响白细胞形态,不能用于白细胞和血小板分类计数。 附录四常用抗凝剂的配制及用法 在医学实验中常需动物的全身抗凝,采出的全血或血浆有的也需加入适当的抗凝剂抗凝。对抗凝剂的要求是:用量少、溶解度大、不带进干扰实验的杂质。 一、肝素 (1)肝素抗凝作用原理 肝素的抗凝作用很强,作死亡复苏等实验时,常用它作动物全身抗凝剂,肝素的抗凝作用主要是抑制凝血致活酶的活力,阻止血小板凝聚以及抑制抗凝血酶等作用,从而使血液不发生凝固。

展开剂的选择

柱层析和TLC是有机化学工作者必须下苦功夫的两项实验技术。这两项技术掌握与否,对于提高实验的效率至关重要。常见的例子是:在柱层析时,由于层析柱中的硅胶填料装得不均匀(没有填严实),使得柱子在淋洗过程中就因为出现太多气泡变花,导致分离效果不好。更常见的例子是:层析柱虽然装得不错,但是由于淋洗剂选择不恰当,结果导致几十毫克产品,用了几百毫升淋洗剂都还没有完全分离。分离同样的东西,熟手可能只需要半个小时,而一个层析技术不过关的人可能半天都不能得到纯品。由此可见,这两项技术掌握与否,对于提高工作效率,减轻工作量,减少有机溶剂的使用,从而对身心健康和环境保护都有明显的作用。柱层析关键在于柱子是否装好和淋洗剂是否选择恰当。而淋洗剂的选择则是通过TLC确定。这里要指出的一点是:TLC的作用除了跟踪反应进程,检测试剂和原料纯度外,一个重要的用途就是为柱层析选择适当的淋洗剂。 首先谈柱层析 装柱子(填硅胶)时,有两种方法:即湿法装柱和干法装柱,二者各有优劣。不论干法还是湿法,硅胶(固定相)的上表面一定要平整,并且硅胶(固定相)的高度一般为15cm左右,太短了可能分离效果不好,太长了也会由于扩散或拖尾导致分离效果不好。 湿法装柱是先把硅胶用适当的溶剂拌匀后,再填入柱子中,然后再加压用淋洗剂“走柱子”。本法最大的优点是一般柱子装得比较结实,没有气泡。 干法装柱则是直接往柱子里填入硅胶,然后再轻轻敲打柱子两侧,至硅胶界面不再下降为止,然后再填入硅胶至合适高度,最后再用油泵直接抽,这样就会使得柱子装得很结实。接着是用淋洗剂“走柱子”,一般淋洗剂是采用TLC分析得到的展开剂的比例再稀释一倍后的溶剂。通常上面加压,下面再用油泵抽,这样可以加快速度。 干法装柱较方便,但最大的缺陷在于“走柱子”时,由于溶剂和硅胶之间的吸附放热(可以用手摸柱子明显感觉到),容易产生气泡,这一点在使用低沸点的淋洗剂(如乙醚,二氯甲烷)时更为明显。虽然产生的气泡在加压的情况下不易察觉,但是一旦撤去压力,如在上样、加溶剂等操作的时候,气泡就会释放出来,严重时整个柱子变花,样品不可能平整地通过,当然也就谈不上分离了。解决的办法是:第一、硅胶一定要填结实;第二、一定要用较多的溶剂“走柱子”,一定要到柱子的下端不再发烫,恢复到室温后再撤去压力。 也有介绍在硅胶的最上层填上一小层石英砂,防止添加溶剂的时候,使得样品层不再整齐。但我的感觉是如果小心上样,小心添加溶剂,则没有这个必要。 上样也有干法和湿法之分:干法上样就是把待分离的样品用少量溶剂溶解后,加入少量硅胶,拌匀后再旋去溶剂。如此得到的粉末再小心加到柱子的顶层。干法上样较麻烦,但可以保证样品层很平整。湿法上样就是用少量溶剂(最好就是展开剂,如果展开剂的溶解度不好,则可以用一极性较大的溶剂,但必须少量)将样品溶解后,再用胶头滴管转移得到的溶液,沿着层析柱内壁均匀加入。然后用少量溶剂洗涤容器、加入,走柱,至溶剂与硅胶上表面齐平;洗涤层析柱内壁,再如法操作。湿法较方便,熟手一般采用此法。

吸附剂

吸附剂(吸收剂) 用以选择性吸附气体或液体混合物中某些组分的多孔性固体物质称吸附剂。吸附剂通常制成球形、圆柱形或无定形的颗粒或粉末。优良吸附剂应具有的特性主要是单位质量吸附剂具有较大的表面积,对吸附质具有较大的吸附能力(即平衡吸附量大)。并且具有良好的选择性,即能优先吸附混合物中某些组分。此外,还要求容易再生(即平衡吸附量对温度或压力的变化敏感),具有足够的强度和耐磨性等。 常用的吸附剂有:①活性白土、硅藻土等天然物质。常用于油品和糖液的脱色精制;②活性炭。由各种含炭物质经炭化和活化处理而成,耐酸碱但不耐高温,吸附性能良好,多用于气体或液体的除臭、脱色、以及溶剂蒸气回收和低分子烃类的分离;③硅胶。由硅酸钠水溶液脱钠离子制成的坚硬多孔的凝胶颗粒,能大量吸收水分,吸附非极性物质量很少,常用于气体或有机溶剂的干燥以及石油制品的精制;④活性氧化铝。由氧化铝的水合物加热脱水制成的多孔凝胶和晶体的混合物,常用于气体和有机物的干燥;⑤合成沸石。又称分子筛,人工合成的硅铝酸盐,具有均匀的孔径,热稳定性高,选择性好,用于气体和有机溶剂的干燥及石油馏分的吸附分离等;⑥合成树脂。具有巨型网状结构,常用的有非极性树脂,如苯乙烯-二乙烯基苯共聚体;极性树脂,如聚甲基丙烯酸酯,用于废水处理、维生素的分离、药剂的脱色和净制等。

9.1.1、吸附现象及其工业应用 1、吸附分离应用背景: 吸附操作在化工、轻工、炼油、冶金和环保等领域都有着广泛的应用。如气体中水分的脱除,溶剂的回收,水溶液或有机溶液的脱色、脱臭,有机烷烃的分离,芳烃的精制等。 2、吸附的定义及概念: 固体物质表面对气体或液体分子的吸着现象称为吸附。其中被吸附的物质称为吸附质,固体物质称为吸附剂。3、吸附机理的分类: 根据吸附质和吸附剂之间吸附力的不同,吸附操作分为物理吸附与化学吸附两大类。 ⑴、物理吸附或称范德华吸附:它是吸附剂分子与吸附质分子间吸引力作用的结果,因其分子间结合力较弱,故容易脱附,如固体和气体之间的分子引力大于气体内部分子之间的引力,气体就会凝结在固体表面上,吸附过程达到平衡时,吸附在吸附剂上的吸附质的蒸汽压应等于其在气相中的分压。 ⑵、化学吸附:是由吸附质与吸附剂分子间化学健的作用所引起,其间结合力比物理吸附大得多,放出的热量也大得多,与化学反应热数量级相当,过程往往不可逆。化学吸附在催化反应中起重要作用。本章主要讨论物理吸附。 4、吸附机理的判断依据: ⑴、化学吸附热与化学反应热相近,比物理吸附热大得多。如二氧化碳和氢在各种吸附剂上的化学吸附热为83740J/mol和62800J/mol,而这两种气体的物理吸附热约为25120J/mol和8374J/mol。 ⑵、化学吸附有较高的选择性。如氯可以被钨或镍化学吸附。物理吸附则没有很高的选择性,它主要取决于气体或液体的物理性质及吸附剂的特性。 ⑶、化学吸附时,温度对吸附速率的影响较显著,温度升高则吸附速率加快,因其是一个活化过程,故又称活化吸附。而物理吸附即使在低温下,吸附速率也可能较大,因它不属于活化吸附。 ⑷、化学吸附总是单分子层或单原子层,而物理吸附则不同,低压时,一般是单分子层,但随着吸附质分压增大,吸附层可能转变成多分子层。 5、吸附剂的再生及方法:

消毒剂的种类及应用(终审稿)

消毒剂的种类及应用文稿归稿存档编号:[KKUY-KKIO69-OTM243-OLUI129-G00I-FDQS58-

一、化学消毒剂的基本分类 按用途分类: 环境消毒剂和带畜(禽)体表消毒剂(包括饮水、器械等) 按杀菌能力分类: ⑴高效(水平)消毒剂:即能杀灭包括细菌芽胞在内的各种微生物。 ⑵中效(水平)消毒剂:即能杀灭除细菌芽胞在外的各种微生物。 ⑶低效(水平)消毒剂:即只能杀灭抵抗力比较弱的微生物,不能杀灭细菌芽胞、真菌和结核杆 菌,也不能杀灭如肝炎病毒等抗力强的病毒和抗力强的细菌繁殖体 的。 按物品性状: 固体、液体、气体 按化学性质分类 (一)过氧化物类消毒剂:指能产生具有杀菌能力的活性氧的消毒剂 如过氧乙酸、过氧化氢、过氧戊二酸、臭氧、二氧化氯等杜邦子公司Antec的 “Virkon” 过一硫酸氢钾复合盐消毒剂等。 缺陷及危害:过氧乙酸、过氧化氢、过氧戊二酸不稳定、刺激性强,长期使用对人和动物眼睛、呼吸道黏膜、环境有强力的破坏

过氧化物消毒剂性能对照表 (二)含氯消毒剂:指在水中能产生具有杀菌活性的次氯酸的消毒剂 (1)有机含氯消毒剂:如二氯异氰尿酸钠、二(三)氯异氰尿酸、氯胺-T 、二氯二甲基海 因、四氯甘脲氯脲等的消毒剂 (2)无机含氯消毒剂:漂白粉(CaOCl 2)、漂(白)粉精(高效次氯酸钙Ca(ClO)22H 2O)、次氯酸 钠(NaClO.5H 2O )、氯化磷酸三钠(Na 3PO 4. 1/4NaOCl . 12H 2O)等。 缺陷及危害:代谢物:三氯甲烷高致癌、绝大多数刺激性强,无表 面活性作用 有机含氯消毒剂性能对照表

展开剂的选择

展开剂的选择 最近刚进实验室,用TLC对反应进行检测,但是关于展开剂的资料不多,我们实验室大多就是两个体系:石油醚/乙酸乙酯,氯仿/甲醇,其他的就很少了,所以我下决心把这个实验室比较常用的技术搞清楚。 一般常用溶剂按照极性从小到大的顺序排列大概为:石油迷<己烷<苯<乙醚<乙酸乙酯<丙酮<乙醇<甲醇。使用单一溶剂,往往不能达到很好的分离效果。使用混合溶剂通常使用一个高极性和低级性溶剂组成的混合溶剂,高极性的溶剂还有增加区分度的作用,常用的溶剂组合有: Petroleum ether/Ethyl acetate,petroleume ther/Acetone,Petroleum ether/Ether, Petroleum ether/CH 2Cl 2 , ethyl acetate/MeOH,CHCl 3 /ethyl acetate. 展开剂的比例要靠尝试。一般根据文献中报道的该类化合物用什么样的展开剂,就首先尝试使用该类展开剂,然后不断尝试比例,直到找到一个分离效果好的展开剂。 展开剂的选择条件: ①对的所需成分有良好的溶解性; ②可使成分间分开; ③待测组分的Rf在0.2~0.8之间,定量测定在0.3~0.5之间; ④不与待测组分或吸附剂发生化学反应; ⑤沸点适中,黏度较小; ⑥展开后组分斑点圆且集中; ⑦混合溶剂最好用新鲜配制。 很多时候,展开剂的选择要靠自己不断变换展开剂的组成来达到最佳效果。 一般把两种溶剂混合时,采用高极性/低极性的体积比为1/3的混合溶剂,如果有分开的迹象,再调整比例(或者加入第三种溶剂),达到最佳效果;如果没有分开的迹象(斑点较“拖”),最好是换溶剂。对于在硅胶这种酸性物质上易分解的物质,在展开剂里往往加一点点三乙胺,氨水,吡啶等碱性物质来中和硅胶的酸性。(选择所添加的碱性物质,还必须考虑容易从产品中除去,氨水无疑是较好的选择。) 分离效果的好坏和所用硅胶和溶剂的质量很有关系:不同厂家生产的硅胶可能含水量以及颗粒的粗细程度,酸性强弱不同,从而导致产品在某个厂家的硅胶中分离效果很好,但在另一个厂家的就不行。溶剂的含水量和杂质含量对分离效果都有明显的影响。温度,湿度对分离效果影响也很明显,在实际操作中,我们也发现有时同一展开条件,上下午的Rf截然不同。展开剂的选择主要根据样品的极性、溶解度和吸附剂的活性等因素来考虑。在进行薄层层析时,首先应该知道未知化学成分的类型,其极性的大致归属,这些可从提取液或从色谱柱的流动相极性可知;另外某样品里含多种化学成分先按极性不同大致分,然后细分,对于分离未知的化学物质,展开剂的选择也是一个摸索的过程,不应该仅仅从展开剂考虑,应当多因素综合衡量! 一种简单的办法是根据产物的溶解性选择一种极性最强的溶剂(如醇类,乙氰等),再根据实际展开的情况慢慢加入极性弱的溶剂(如四氯化碳、石油醚、二氯甲烷等)调节体系的极性。以得到最好的展开效果。把我的祖传秘方告诉你吧 PE(60-90) EtOAc/PE=1:2 EtOAc/PE/AcOH=15:5:1 EtOAc/AcOH/n-Butanol/H2O=2:1:1:1 8年来我用这四种体系,没有出现过什么问题我一直在用的是乙酸乙酯:环已烷,不断调

常用抗凝剂

常用抗凝剂种类及应用 一、基本概念 凝固:将血液从血管中抽出,如果未经抗凝,也不做其他处理,通常在几分钟内便自动凝固。一定时间分离后上层析出的淡黄色液体为血清。血浆与血清的区别是:血清中无FIB 抗凝:应用物理的或化学的方法,除掉或抑制血液中的某些凝血因子,阻止血液凝固,称为抗凝。离心分离后的上层淡黄色液体为血浆。 抗凝剂:能够阻止血液凝固的化学试剂或物质,称为抗凝剂或抗凝物质。 促凝:帮助血液快速凝固的过程。 促凝剂:帮助血液快速凝固以达血清快速析出的物质。一般成分为胶类物质。 二、常用抗凝剂的抗凝原理及适用 1、肝素是用于血液化学成分检测的首选抗凝剂。肝素是一种含有硫酸基团的粘多糖,是分散相物质平均分子质量为15000。其抗凝原理主要是通过与抗凝血酶Ⅲ结合引起抗凝血酶Ⅲ构型发生变化,加速凝血酶-凝血酶复合体形成而产生抗凝作用。此外,肝素还能借助血浆辅助因子(肝素辅助因子Ⅱ)来抑制凝血酶。常用肝素抗凝剂是肝素的钠、钾、锂、铵盐,其中以肝素锂最好,但其价格较贵,钠、钾盐会增加血液中的钠、钾含量,铵盐会增加尿素氮的含量。通常用肝素抗凝的剂量为10.0~12.5 IU/ml血液。肝素对血液成分干扰较少,不影响红细胞体积,不引起溶血,适用于做细胞渗透性试验、血气、血浆渗透量、红细胞压红积及普通生化测定。但肝素具有抗凝血酶作用,不适合做血凝试验。另外,肝素过量可引起白细胞聚集和血小板减少,所以不适合做白细胞分类和血小板计数,更不能用于止血检验。此外,肝素抗凝血不能用于制作血涂片,因为Wright染

色后出现深蓝色背景,影响显微镜减产。肝素抗凝血应于短时间内使用,否则放置过久血液又可凝固。 2、乙二胺四乙酸盐(EDTA盐)。EDTA能与血液中Ca2+结合成螯合物,凝血过程被阻断,血液不能发生凝固。EDTA盐有钾、钠、锂盐,国际血液学标准化委员会推荐使用的是EDTA-K2,其溶解度最高,抗凝速度最快。EDTA盐通常配成质量分数是15%的水溶液,每ml血液加1.2mgEDTA,即每5ml血液加0.04ml 15%EDTA溶液。EDTA盐可在100℃下干燥,抗凝作用不变。EDTA盐不影响白细胞计数及大小,对红细胞形态影响最小,抑制血小板的聚集,适用一般血液学检测。如果抗凝剂浓度过高,渗透压上升,会造成细胞皱缩。EDTA溶液pH与盐类关系较大,低pH可使细胞膨胀。EDTA-K2可使红细胞体积轻度膨胀,采血后短时间内平均血小板体积非常不稳定半小时后趋于稳定。EDTA-K2使Ca2+、Mg2+下降,同时使肌酸激酶、碱性磷酸酶降低,EDTA-K2的最佳浓度为1.5mg/ml血液,如果血少,中性粒细胞会肿胀分叶消失,血小板会肿胀、崩解,产生正常血小板的碎片,使分析结果产生错误。EDTA盐能抑制或干涉纤维蛋白凝块形成时纤维蛋白单体的聚合,不适于血凝和血小板功能检测,也不适用于钙、钾、钠及含氮物质的测定。此外,EDTA能影响某些酶的活性和抑制红斑狼疮因子,故不适合制作组化染色和检查红斑狼疮细胞的血涂片。 3、枸橼酸盐主要是枸橼酸钠,其抗凝原理是能与血液中的Ca2+结合形成螯合物,使Ca2+失去凝血功能,凝血过程被阻断,从而阻止血液凝固。枸橼酸钠有Na3C6H5O7·2H2O和2Na3C6H5O7·11H2O两种晶体,通常用前者配成3.8%或3.2%的水溶液,与血液按照1:9体积混合。大部分凝血试验都可用枸橼酸钠抗凝,它有助于Ⅴ因子和Ⅷ因子的稳定,并且对平均血小板体积及其他凝血因子影响较小,可用于血小板功能分析。枸橼酸钠细胞毒性较小,也是输血中血液保养液的成分之一。但是,枸橼酸钠6mg才能抗凝1ml血液,碱性强,不适用于血液分析和生化测验。

吸附剂的种类

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吸附不同大小的分子或不同极性的离子。天然无机材料制成的吸附剂主要是粒状的,其使用受刮风、降雨、降雪等自然条件的影响。 4、合成吸附剂 合成吸附剂是专门为纯的有机液体研制的,能有效地清除陆地泄漏物和水体的不溶性漂浮物。对于有极性且在水中能溶解或能与水互溶的物质,不能使用合成吸附剂清除。能再生是合成吸附剂的一大优点。常用的合成吸附剂有聚氨酯、聚丙烯和有大量网眼的树脂。 聚氨酯有外表敞开式多孔状、外表面封闭式多孔状及非多孔状几种形式。所有形式的聚氨酯都能从水溶液中吸附泄漏物,但外表面敞开式多孔状聚氨酯能像海绵一样吸附液体。吸附状况取决于吸附剂气孔结构的敞开度、连通度和被吸附物的黏度、湿润力,但聚氨酯不能用来吸附处理大泄漏或高毒性泄漏物。 聚丙烯是线性烃类聚合物,能吸附无机液体或溶液。分子量结晶度较高的聚丙烯具有更好的溶解性和化学阻抗,但其生产难度和成本费用高。不能用来吸附处理大泄漏或高毒性泄漏物。 最常用的两种树脂是聚苯乙烯和聚甲基丙烯酸甲酯。这些树脂能与离子类化合物发生反应,不仅具有吸附性,还表现出离子交换。 (摘自:《环境应急响应实用手册》) 吸附剂 目录[隐藏] 一、概述 二、吸附剂的种类 1.硅胶 2.活性炭 3.沸石分子筛 4.碳分子筛 三、吸附剂的物理性质

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