“…Among the detection methods reported, the following deserve special mention: ninhydrin (18, 737, 996, 1034, 1199, 1274), chlorine and otolidinc (1033), 6-ehloromereuri-2-nitrophenol (for thiols) (13), isatin (116, 498), chloramine-T and a diazo reaction (for aspartic acid) (1135), the Sakaguchi reaction (96), impregnation of the paper with l,2-naphthoquinone-4-sulfonate for intensifying the fluorescence test (842), and detection by heating the paper to 200°C. (633).…”