Hydrochloric acid vapor reagent

Reagent solution Place 10 ml cone, sulfuric acid in a twin-trough chamber and add 2 ml cone, hydrochloric acid dropwise and with care. 

Chalcones yield orange-red to brown-colored zones [4] as do 4-aminoazobenzene derivatives, but their colors begin to change after 10 min and slowly fade [5]. Penicillic acid is visible as a greyish-black zone [18]. 

Note The reagent can be employed on silica gel, kieselguhr. Si 50 000 and RP layers [6]. The fluorescence intensities of the chromatogram zones can be increased by dipping in a solution of liquid paraffin in hexane or chloroform [8,11]. 

Ascending, one-dimensional double development (stepwise technique) in a trough chamber with chamber saturation. 

Layer HPTLC plates Silica gel 60 with concentrating zone 

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The dried chromatograms are first exposed to hydrochloric acid vapor (reagent 1) for a few minutes and then heated to 120 °C for 5 min to remove excess hydrochloric acid. After cooling to room temperature the TLC/HPTLC plates are successively sprayed homogeneously with spray solutions 1 and 2. They are then dried briefly in a stream... 

Hydrochloric acid vapor reagent 86, 303 Hydrocortisone 221 Hydrogen lamp 21, 22 Hydrogen peroxide 368 -, reagent 307... 

Hydrochloric Acid Vapor Reagent Substances Hydrochloric acid (32%)... 

Hydrochloric acid vapor reagent reacts with organic substances to produce colored products and finally to dark brown colored carbon (25). 

Note The reagent can also be applied by first treating the chromatogram with an unacidified solution of vanillin and then exposing it to hydrochloric acid vapor [3, 9], Catechin derivatives should be evaluated rapidly (within 10 min), since the red coloration is not stable in daylight and fades relatively quickly [5, 9]. 

B. Synthesis of m- 4-[o-(2-Chloro-5-fluorosulfonylphenylureido)-phenoxy]butoxy bematnidine (11).To 5.2 mmoles of 3-amino-4-chloro-benzenesulfonylfluoride (18) (Aldrich Chemical Co.) are added 25 ml of benzene (dry reagent grade) and 5.5 mmoles of p-nitrophenylchlorofor-mate (19) (Aldrich Chemical Co.). The mixture is stirred at reflux for 4 hr, at which point hydrochloric acid vapor is no longer detectable. The mixture is cooled, and i T-(2-chloro-5-fluorosulfonyl-0-(4-nitrophenyl) carbamate (W) is collected. Recrystallization is from methylene chloride. To a solution of m-[4-(o-aminophenoxy)butoxy]benzamidine p-toluenesulfonate (21) in 10 ml of DMF are added 10.0 mmoles of pyri-... 

Note The TDM reagent can be used everywhere, where o-tolidine is employed. It can also be used on chromatograms, that have already been treated with ninhydrin, Pauly or ammonia perchlorate reagent or with iodine vapor [1]. Water may be used in place of 80% 2-propanol when making up solutions II, III and IV. The chlorine gas atmosphere in the chromatography chamber can also be created by pouring 5 ml hydrochloric acid (ca. 20%) onto 0.5 g potassium permanganate in a beaker such a chlorine chamber is ready for use after 2 min. 

No visualization reagent is required because of the characteristic natural coloration of the pigments. Pour 6 M hydrochloric acid into a shallow tray and hold the layer over the escaping vapors (Caution Work in a hood) to confirm the location of the neoxanthin zone (turns from yellow to blue-green) and violaxan-thin zone (yellow to blue). The other leaf carotenoids remain yellow. 

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