Complex sentence: It is used in Ehrlich's reagent, which may be used as a TLC stain, or as a reagent to detect urobilinogen in fresh, cool urine.If urine sample is left to oxidize in air to form urobilin the reagent will not detect the urobilinogen.
Split into simpler sentences: It is used in Ehrlich's reagent, which may be used as a stain in thin layer chromatography, or as a reagent to detect urobilinogen in fresh, cool urine. If a urine sample is left to oxidize in air to form urobilin the reagent will not detect the urobilinogen.