I tried to make a vanilin /H2SO4 visualization reagents for TLC use, my receipt is as folllows
0.5g vanillin in 10L EtOH, 8ml H2SO4 in 20mL water,and mix them together, the reagent will give a light violet color, but recently the same receipt does not work, it became yellow all the time after I mix them together, and the visualization result is less optimistic, could you share your own receipe please?
15g vanillin in 250 mL EtOH and carefully add 2.5 mL H2SO4 (preferably at 0°C). Gives a colorless/light yellow solution. Should be kept in a fridge and protected from light. Turns purple over time. If the partly decomposed version (purple) works better for you, don't protect it from light. Looks to me like your problem is that you got better at making it (or you're being more carefull with it's storage)
15g vanillin in 250 mL EtOH and carefully add 2.5 mL H2SO4 (preferably at 0°C). Gives a colorless/light yellow solution. Should be kept in a fridge and protected from light. Turns purple over time. If the partly decomposed version (purple) works better for you, don't protect it from light. Looks to me like your problem is that you got better at making it (or you're being more carefull with it's storage)
Pls find attached procedure and details for Vanillin reagents from the following book:
Hellmut Jork, Werner Funk, Walter Fischer, Hans Wimmer
Thin-Layer Chromatography- Reagents and Detection Methods
Volume la
Physical and Chemical Detection Methods: Fundamentals, Reagents I
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