title: Chromatographic location and colorimetric determination of mercaptans, prolines and free radical precursors.
abstract: A new reagent, 7,7,8,8-tetracyanoquinodimethan (TCNQ), is introduced for the colorimetric determination of free radical precursors, such as cysteine, proline, hydroxyproline, the phenoxazine family and mercaptans. TCNQ is also useful in the location and characterization on paper or thin-layer chromatograms of proline, hydroxyproline, cysteine, polynuclear compounds, mercaptans, thiocarbonyl amides and thiosemicarbazones. In addition, aminoacid derivatives, such as the N-(phenylthiocarbamyl) amino-acids and the 3-phenylthiodantoins, can be located and characterized on chromatograms. TCNQ has been applied to the location and characterization of atmospheric proline, carbazole and 11H-benzo[a]carbazole. For characterization purposes absorption spectra were obtained directly from glass-fibre, paper, or thin-layer chromatograms from about 300 to 900 mmu.
authors.affiliation: Bureau of Disease Prevention and Environmental Control, National Center for Air Pollution Control, U.S. Department of Health, Education, and Welfare, Public Health Service, 4676 Columbia Parkway, Cincinnati, Ohio 45226, U.S.A.
authors.forename: E
authors.initials: E
authors.lastname: Sawicki
authors.forename: C R
authors.initials: CR
authors.lastname: Engel
authors.forename: W C
authors.initials: WC
authors.lastname: Elbert