TLC常用展開劑及應(yīng)用

1、展開劑的極性規(guī)律 單一溶劑的極性大小順序?yàn)椋菏兔眩ㄐ。┮画h(huán)己烷一四氯化碳_二氯乙烯一苯一甲苯_二氯甲烷一氯仿_乙醚_乙酸乙 酯f乙酸甲酯f丙酮f正丙醇f甲醇f吡啶f乙酸（大）混合溶劑的極性順序：苯：氯仿（1+1）f 環(huán)己烷：乙酸乙酯（8+2） f氯仿：丙酮（95+5） f苯：丙酮（9+1） f苯：乙酸乙酯（8+2） f氯仿：乙醚（9+1） f苯：甲醇（95+5） f苯：乙醚（6+4） f 環(huán)己烷：乙酸乙酯（1+1） f氯仿：乙醚（8+2） f氯仿：甲醇（99+1） f苯：甲醇（9+1） f氯仿：丙酮（85+15） f苯：乙醚（4+6） f苯：乙酸乙酯（1+1） f氯仿：甲醇（95+5） f氯

2、仿：丙酮（7+3） f苯：乙酸乙酯（3+7） f苯：乙醚（1+9） f乙醚：甲醇（99+1） f 乙酸乙酯：甲醇（99+1） f苯：丙酮（1+1） f氯仿：甲醇（9+1）1、生物堿（1）沉淀反應(yīng)一一碘化汞鉀試劑一白色或淺黃色沉淀碘化鉍鉀試劑一橘紅色沉淀碘一碘化鉀試劑一淺棕或暗棕色沉淀硅鎢酸試劑一淺黃或黃棕色沉淀磷鎢酸試劑一淺黃色沉淀磷鉬酸試劑一白色或淡黃色沉淀苦味酸試劑一黃色結(jié)晶或非結(jié)晶形沉淀 鞣酸試劑一棕黃色沉淀 氯化金試劑一黃色結(jié)晶氯化鉑試劑一白色結(jié)晶雷氏銨鹽一紅色無定形沉淀（2）薄層層析檢查：吸附劑一一堿性氧化鋁（III級，干法鋪板）硅膠G （稀堿濕法鋪板）展開劑一一氯仿：甲醇 顯色UV

3、；碘化鉍鉀2、氨基酸、多肽、蛋白質(zhì)（1）加熱沉淀試驗(yàn)：加熱煮沸一混濁或沉淀（蛋白質(zhì)）+5%H2SO4 （不加熱）一混濁或沉淀（2）雙縮脲反應(yīng)： +40%NaOH， 1%CuSO4 一紫色、紅色或紫紅色（多肽、蛋白質(zhì)）（3）茚三酮反應(yīng)： +0.2%茚三酮試液 一藍(lán)或藍(lán)紫色（氨基酸、多肽、蛋白質(zhì)）（4）吲哚醌反應(yīng)： +吲哚醌試液 一各種顏色（氨基酸）（5）Millon反應(yīng)：+Hg, H2NO2 一紅色（蛋白質(zhì)分子中有酪氨酸組成）（6）Hopkins-Cole反應(yīng)：+乙醛酸，濃硫酸一各色（蛋白質(zhì)分子中有色氨酸組成）(7)氨基酸的薄層層析檢查：吸附劑一一硅膠G展開劑 n-BuOH，n-BuOH： HA

4、c： H2O顯色劑一一0.25%茚三酮試液一紫紅色斑點(diǎn)3、有機(jī)酸( 1) PH 試紙檢查溴酚蘭試液：噴灑一藍(lán)色背景黃色斑點(diǎn)薄層層析檢查：吸附劑一一硅膠G或酸性氧化鋁展開劑一一 C6H6： EtOH顯色劑一一0.1%溴酚蘭試液一黃色4、酚類和鞣質(zhì)FeCI3試劑：+l%FeCI3試液一藍(lán)、暗綠或藍(lán)紫色三氯化鐵-鐵氰化鉀試劑：噴灑一藍(lán)色斑點(diǎn)香草醛-鹽酸試劑：噴灑一紅色(間苯二酚、間苯三酚)重氮鹽試劑：+對硝基苯胺、亞硝酸鈉一紅色薄層層析檢查：吸附劑一一硅膠G或纖維素展開劑一一 n-BuOH： HAc： H2O；15%HAc 顯色劑一一1% FeCI3試液1%三氯化鐵-1%鐵氰化鉀試液一藍(lán)、綠或黑色鞣

5、質(zhì)與酚類的區(qū)別： +明膠 一一 沉淀上清液+1%FeCI3試液一藍(lán)、暗綠或藍(lán)紫色5、糖和苷斐林試劑： +硫酸銅、酒石酸鉀鈉 一一 磚紅色沉淀(還原糖)(一) +1%HCI +NaOH 沉淀(苷元)30min上清液(+)(多糖、苷)Molish反應(yīng)：+a-萘酚-濃硫酸一紫紅色環(huán)銀鏡反應(yīng)：+0.1N硝酸銀、5N氨水一銀褐色(還原糖)薄層層析檢查：吸附劑一一硅膠G或纖維素展開劑一一 n-BuOH： Pd： H2O；15%HAc顯色劑一一 苯胺-鄰苯二甲酸6、皂苷泡末試驗(yàn)：振搖一大量持續(xù)性泡末+0.1M HCI 二管泡末高度相同(三萜皂苷)+0.1M NaOH 堿管高于酸管(甾體皂苷)溶血試驗(yàn)： +2

6、%紅血球懸浮液 一溶血 Lieberman-Burchard反應(yīng)：+醋酐-濃硫酸 紫紅色(三萜皂苷)黃-紅-紫-污綠(甾體皂苷)7、甾體Lieberman-Burchard反應(yīng)：+醋酐-濃硫酸一黃-紅-紫-污綠氯仿-濃硫酸反應(yīng)： +氯仿-濃硫酸 氯仿層一紅或青色硫酸層一綠色熒光五氯化銻或三氯化銻反應(yīng)： +SbCI3 或 SbCI5 一紅色(4)薄層層析檢查：吸附劑一一中性氧化鋁或硅膠G展開劑 C6H6-MeOH；CHCl3-MeOH顯色劑一一 10%磷鉬酸一藍(lán)-藍(lán)紫色5%三氯化銻試液一紅、棕紅或綠色8、黃酮鹽酸-鎂粉反應(yīng)：+HCI-Mg 紅色三氯化鋁反應(yīng)：+AICI3 黃色濃氨水反應(yīng)：+NH3

7、 一亮黃或橙色薄層層析檢查：吸附劑一一聚酰胺或硅膠G展開劑一一 MeOH-H2O；EtOH-H2O顯色劑一一 UV-亮黃或黃綠色熒光1%三氯化鋁試液一亮黃色9、香豆素、內(nèi)酯開閉環(huán)反應(yīng)：+1%NaOH-澄清+2%HCI-混濁 異羥污酸鐵反應(yīng)：+7%鹽酸羥胺、10%KOH +稀HCI、1%FeCI3 一紅色重氮鹽試劑：+對硝基苯胺、亞硝酸鈉一紅色薄層層析檢查：吸附劑一一酸性硅膠G或硅膠G或酸性氧化鋁展開劑一一 甲苯-乙酸乙酯-甲酸(5： 4： 1)顯色劑一一 UV-藍(lán)色熒光異羥污酸鐵試液一紅色10、強(qiáng)心苷Kedde試劑：+3, 5-二硝基苯甲酸試液一紫紅色Baljet試劑：+堿性苦味酸試液一橙或橙

8、紅色Legal試劑：+亞硝酰鐵氰化鈉試液一紫紅色K-K反應(yīng)：+FeCI3/冰HAc、濃H2SO4- 上層綠藍(lán)色(2-去氧糖)界面紅棕色薄層層析檢查：吸附劑一一硅膠G或中性氧化鋁展開劑一一 n-BuOH： HAc： H2O(4： 1： 5)顯色劑一一堿性3, 5-二硝基苯甲酸試液一紫紅色堿性苦味酸試液一橙紅色11、蒽醌堿液反應(yīng)： +10%NaOH 一紅色 +H2O2 一紅色不褪 +H+ 一紅色褪去醋酸鎂反應(yīng)： +1%MgAc2 一紅色薄層層析檢查：吸附劑一一硅膠G展開劑Pet： EtOAc顯色劑UV黃色熒光5%NaOH 一紅色12、揮發(fā)油、油脂油斑檢查：油斑揮發(fā) 一揮發(fā)油； 油斑不消失一油脂或類

9、脂磷鉬酸反應(yīng)：噴灑 5%磷鉬酸試液 一藍(lán)色(油脂、三萜、甾醇)TLC VisuaIization ReagentsThis 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 (mat

10、erial 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 attem

11、pted. 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 time in the oven).Always spray any of these reagents onto plates in a well ventilated hood while wearing saf

12、ety 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 always overspray to enhance the detection.When information about the results of using the visualization reagents was available, this was put undereach reagen

13、t 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 Chemica

14、ls catalog or on the website ( HYPERLINK ).Aluminium chlorideFor flavonoidsSpray 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 de

15、tection of phenols and arylaminesSolution I: 1g aminoantipyrine (4-aminophenazone) in 100ml 80% ethanolSolution II: 4g potassium hexacyanoferrate (III) in 20ml water, fill to 100ml with ethanolProcedure:Spray with solution IDry 5 minutes with warm airPlace chromatogram in a chamber with vapor from 2

16、5% ammonium solution, making sure that the layer does not contact the liquid.Results: Red-orange to salmon pink spots2-Aminoethyl diphenylborate, see Ethanolamine diphenylborate Ammonium metavanadate, ammonium monovanadate, see Vanadium(V) / sulfuric acid Ammonium molydbateFor detection of phosphori

17、c acid derivativesSolution 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

18、to 60 CHydrolyse di- and triphosphates by spraying perchloric acid (solution I) onto the warm plate. After spraying 2times, 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

19、 plate with tin (II) chloride solution (solution III)Results: Phosphates appear as blue to blue-green spots. Polyphosphates can also be detected by dipping theplates in a solution of ammonium molybdate (1g) dissolved in water (8ml) and perchloric acid (3ml, ca. 70%),filled up to 100ml with acetone.

20、Then phosphates appear as yellow-green spots on a blue background. Also seeMolybdenum blue reaction according to Dittmer and Lester.Aniline phthalate (鄰苯二甲酸胺)For the detection of reducing sugarsDry the developed chromatogramSpray with 0.93g aniline and 1.66g o-phthalic acid dissolved in 100ml n-buta

21、nol saturated with water.Briefly dry with hot air, then heat to 105 C for 10 minutesResults: Substance spots show different colors on an almost colorless background. Some spots give fluorescence at 365nm.p-Anisaldehyde -sulfuric acid (對甲氧基苯甲醛-硫酸)For detection of phenols, sugars, steroids, and terpen

22、esSpray with a solution of freshly prepared 0.5ml p-anisaldehyde in 50ml glacial acetic acid and 1ml 97% sulfuric acid. and heat to 105C until maximum visualization of spots. The background might be brightened by water vapor.Results: Lichen constituents, phenols, terpenes, sugars, and steroids turn

23、violet, blue, red, grey or green.For detection of sugarsSpray with a solution of freshly prepared 1ml p-anisaldehyde, 1ml 97% sulfuric acid in 18ml ethanol and heat at110C.Results: Sugar phenylhydrazones produce green-yellow spots in 3 min. Sugars will produce blue, green, violetspots in 10min. Also

24、 detects digitalis glycosides.p-Anisidine HydrochlorideFor detection of carbohydrates / sugarsMix a solution of 3% p-anisidine hydrochloride in n-butanolSpray and heat at 100C for 2-10min.Results: Aldohexoses are seen as green-brown spots, ketohexoses as yellow spots, aldopentoses as green spots, an

25、d uronic acids as red spots.Anisidine phthalateFor detection of carbohydrates and reducing sugarsSpray with a solution of 1.23 g p-anisidine and 1.66g phthalic acid in 100ml 95% ethanol.Results: Hexoses, green; pentoses, red-violet - sensitivity 0.5ug; methylpentoses, yellow-green; uronic acids,brow

26、n - sensitivity 0.1-0.2ug.Antimony (III) chloride (三氯化銻)For detecti on of flav ono idsSpray with a 10% soluti on of an tim ony (III) chloride in chloroformResults: Fluoresc ing spots in long wavele ngth light (360n m).An timo ny (III) chlorideFor detecti on of vitam ins A & D, carote no ids, steroid

27、s, sapoge nins, steroid glycosides, terpe nesSpray with a soluti on of 25g an tim ony (III) chloride in 75ml chloroform (ge nerally a saturated soluti on of an tiom ony (III) chloride in chloroform or carb on tetrachloride is used).Heat 10min at 100C, view un der long wavele ngth light (360nm).Bromi

28、ne / Carbon tetrachloride (四氯化碳)For detecti on of orga no thiophosphorous pesticidesPlace chromatogram in a chamber with a 10% brom ine and tetrachloride without con tact with the liquid.3Bromocresol gree nFor detecti on of orga nic acidsDip chromatogram in a soluti on of 0.1g bromocresol gree n in

29、500ml etha nol and 5ml 0.1M NaOHResults: Acids yield yellow spots on a blue backgro und.Bromthymol blueFor detecti on of lipids and phospholipidsReage nt: 0.1% bromthymol blue in 10% aqueous etha nol made just alkali ne with NH4OHSpray dried plate.Results: Compo unds above produce blue-gree n colors

30、; sen sitivity 0.1-lpg.Chlora nil reage ntFor detecti on of phe nolsSpray with a soluti on of 1% tetrachloro-p-be nzoq uinone in tolue neChlori ne / o-tolidi neFor detecti on of of compo unds form ing chloroami nes, e.g., urea derivatives, carbamated, an tibioticsSoluti on I: 160mg o-tolid ine in 30

31、ml glacial acetic acid, filled to 500ml with distilled water, plus 1g KIsolutionSoluti on II: saturated soluti on of o-tolid ine in 2% acetic acid/0.85% KI soluti on (1:1, v/v)Procedure APlace chromatogram 15-20m in in a chlori ne atmosphere (e.g., Potassium perma ngan ate +10%Hydrochloricacid)Leave

32、 5 minu tes at ambie nt temperature un til the chlor ine is evaporated completely (spray cor ner ofplate to in sure no blue color is see n, show ing complete abse nee of chlor in e).Spray with soluti on IProcedure BSpray with 2% potassium hypochlorite soluti on in waterLeave 1-1.5hr at ambie nt temp

33、eratureSpray with soluti on IICopper sulfate / phosphoric acid (硫酸銅-磷酸)Used as a charri ng reage nt for polymer bound TLC plates (the n ewer hard layer plates)Spray with a soluti on of 10% copper (II) sulfate in 10% phosphoric acidHeat 5-30min at 110CResults: View freque ntly (every 5-10m in) to see

34、 if colored or fluoresce nt spots (at 254 and 360nm) canbe seen.Charr ing can be con ti nued un til spots are brow n, grey or black.Chromosulfuric acidSee un der Potassium dichromate / sulfuric acidDDQ Reage nt (Dichlorodicya noben zoq uinone)For detecti on of phe nolsSpray with a soluti on of 2% 2,

35、3-dichloro-5,6-dicya no-1,4-be nzoq uinone in tolue neDichlorofluoresce in (二氯熒光黃)For the detecti on of sweete ners sacchar ine & cyclamateSpray with a 0.2% soluti on of dichlorofluoresce in in 96% etha nolDry with warm air; if n ecessary, spray with waterView un der 360nm UV lightDichlorofluoresce

36、in / fluoresce in sodium salt (熒光鈉)For detecti on of N-substituted barbituratesSpray with a 0.1% etha no lie soluti on of dichlorofluoresce inThen spray with a 0.1% etha no lie soluti on of fluoresce in sodium salt2,6-Dichloroq uinone -4- chloroimideFor detecti on of an tioxida nts, phe no ls, prima

37、ry and sec on dary aliphatic amin es, sec on dary and tertiaryaromaticami nes, aromatic hydrocarb ons, pharmaceuticals, phe no xyacetic acid herbicides, etcSpray with a freshly prepared 0.5-2% soluti on of 2,6-dichloroq uinon e-4-chloroimide in etha nol (reage ntstablefor 3 weeks if refrigerated).He

38、at 10m in at 110 C; treat with ammo nia vaporp-Dimethylam inoben zaldehydeFor detecti on of sulfo namidesSpray with a soluti on of 1% p-dimethylami noben zaldehyde in 5% hydrochloric acid; add 5% etha nolDetects sulfo namidesp-Dimethylam inoben zaldehyde / hydrochloric acid reage nt (Ehrlichs reage

39、nt)For detecti on of amin es, i ndole derivativesSpray with a soluti on of 1% p-dimethylami noben zaldehyde in cone, hydrochloric acid/metha no l (2:2)Heat plates for 20min at 50 C2,4-D in itrophe ny lhydraz ineFor detecti on of aldehydes and ket onesSpray plate with solutio n of 0.4 g 2,4-DNPH in 1

40、00ml 2N hydrochloric acid, add 1ml etha nolResults: Yellow-red spots will be see n.Diphenylamine (二苯胺)For detecti on of glycosides, glycolipidsReage nt: 10ml 10% diphe nylami ne in etha nol, 100ml HCl and 80ml glacial acetic acidSpray lightly, cover plate with ano ther glass plate, heat 30-40m in at

41、 110C un til positive areas appearResults: Glycolipids produce blue spots.s-Diphe ny lcarbaz oneFor detecti on of barbituratesSpary with a soluti on of 0.1% s-diphe ny lcarbaz one in 95% etha nolResults: Barbiturates will produce purple spots2,2-Diphe ny lpicrylhydrazylFor detecti on of aldehydes an

42、d ket onesReage nt: dissolve 15mg of 2,2-DPPH in 25ml chloroformSpray, heat 5-10min at 110C;Results: Yellow spots on a purple backgro und will be see n.Dithizone (雙硫腙)For detecti on of heavy metal ionsDissolve 20mg dithiz one in 100ml acet one, store in a brow n bottle in a refrigeratorProcedure:Spr

43、ay with dithiz one soluti onSpray with 25% amm onia soluti onDittmer and LesterSee Molybde num blueDrage ndorff reage ntFor detecti on of n itroge n compo un ds, alkaloids, an tiarrhythmic drugs, surfacta ntsSoluti on 1) 1.7g basic bismuth n itrate and 20g tartaric acid in 80ml waterSoluti on 2) 16

44、g potassium iodide in 40ml waterStock soluti on (stable for several weeks in a refrigerator):Mix equal volumes of soluti ons 1 and 2Procedure:Spray with a soluti on of 10g tartaric acid, 50ml water and 5ml stock soluti onEthanolamine diphenylborate (flavone reagent according to Neu)For detection of

45、flavonoidsSpray with a 1% solution of ethanolamine diphenylborate in methanolSpray with a 5% ethanolic solution of polyyethylene glycol for fluorescence stabilizationIrradiate 2 minutes with intense 365nm UV lightView under 365nm UV lightErhlichs reagentSee p-DimethylaminobenzaldehydeEmerson reagent

46、See 4-aminoantipyrine/potassium hexa-cyanoferrate (III)Fast Blue B reagentFor detection of cannabinoids, phenols, tanning agents, amines with can be coupledSpray with a solution of 0.5g Fast Blue B (tetraazotized di-o-anisidine) in acetone/water (9:1, v/v), always prepared freshThen overspray with 0

47、.1M sodium hydroxide solutionResults: Cannabinoids turn dark red/purple in colorFerric Chloride / sulfuric acidUsed 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 110CRes

48、ults: 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 NeuSee ethanolamine diphenyl borateFluorescamineFor detection of primary and secondary amines, pept

49、ides, sulfonamides, e.g., nitrosoamines after photolysisSpray plate with a solution of 0.1mg/ml 4-phenyl-spirofuran-2(3H),1-phthalan-3,3-dione in acetone prepared fresh dailyFor stabilization of fluorescence at 366nm spray with 10g triethylamine, brought to 100ml with dichloromethane.Fluorescent Ind

50、icatorFor detection of compounds which absorb UV lightSome TLC plates when manufactured have an inorganic fluorescent indicator added to the slurry poured tomake the final plates. This type of indicator will not dissolve or elute off. They are activated at 254nm or 360nm(see recommendations of the m

51、anufacturer 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 h

52、ave some fluorescence of their own, so various colors against a dark background would be seen.Formaldehyde / sulfuric acidFor detection of alkaloids, aromatic hydrocarbons, e.g., antihypertensive drugsSpray with a solution of 37% formaldehyde in conc. sulfuric acid (1:10) immediately after taking th

53、e plate fromthe developing chamber. Heating is not necessary.Results: various colored spots.Formaldehyde / phosphoric acidFor detection of steroid alkaloids, steroid sapogenins and phenothiazine derivatives6Spray with a solution of 0.03g formaldehyde in 100ml of 85% phosphoric acid with stirring at

54、room temperature.The reagent is stable for several weeks.Furfural / sulfuric acidFor detection of carbamate estersSpray solution I: 1% solution of furfural in acetoneSpray solution II: 10% solution of sulfuric acid in acetoneSpray plate with I, then II.Gen tia n Violet Brom ineFor detection of lipid

55、sSpray 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.Gibbs reagentFor detection of phenols. For further applications see 2,6-dichloroquinone-4-chloroimideSpray with a solution of 3% 2

56、,6-dibromo-N-chloro-p-benzoquinone imine in toluene or methanol.Hydroxylamine / iron (III) chlorideFor detection of amides, lactones, carboxylic acid esters and anhydridesSolution 1) Mix 1 vol part of 7g hydroxylammonium chloride in 100ml methanol w 1 vol part of a solution of 7.2 gpotassium hydroxi

57、de in 100ml methanol. Filter from precipitated potassium chloride.Solution 2) 2% solution of iron (III) chloride in 1% aqueous hydrochloride acidSpray air dried plate first with solution 1, then with solution 2Iodine containing compoundsDetection by decomposition under UVDry plates at 100 CAfter coo

58、ling spray with a small amount of 50% acetic acidIrradiate some minutes with unfiltered UV light.Results: Iodine compounds show weakly violet to brown spots. The color can be enhanced by spraying with10% acetic acid and irradiation with UV light (sudden appearance of blue spots).Iodine vaporRelative

59、ly unspecific universal reagent for many organic compoundsCharge chamber with some crystals of iodinePlace developed, dried chromatogram in iodine vaporResults: spots turn tan-brown in colorIodoplatinateFor detection of organic nitrogen compounds, alkaloids, e.g., cocaine metabolitesSpray with a fre

60、shly prepared mixture of 3ml hexachloroplatinic (IV) acid solution (10%) in 97ml/min water and100ml 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 a