Phenylenediamine — Trichloroacetic Acid Reagent

Dipping solution Dissolve 50 mg 1,2-phenylenediamine in 50 ml 10% ethanolic trichloroacetic acid. 

Storage The reagent solution should always be made up freshly. 

The following reactions are to be expected with ascorbic acid and dehydroascorbic 

The chromatogram is freed from mobile phase in a stream of cold air, either immersed in the reagent solution for 5 s or homogeneously sprayed with it and then heated to 110—120°C for 10—15 min [2]. 

Chromatogram zones are produced which exhibit a green fluorescence under long-wavelength UV hght (2 = 365 nm). 

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