title: Selective thiourea optical probe based on thiourea-induced removal of chloroacetyl group from chloroacetylamine.
abstract: A novel chromogenic probe for thiourea, N-chloroacetyl parafuchsin (CAP), was designed and synthesized. The method was based on the reaction of CAP with thiourea, resulting in the initial formation of the S-substituted thioformamidine hydrochloride, which would then undergo the intramolecular amidinolysis to liberate the corresponding amine, and thus leading to an absorbance increase at visible spectral range. Based on this mechanism, a highly selective optical probe for thiourea was developed. Under optimal conditions, absorbance increase (DeltaA) at 562 nm is proportional to thiourea concentration up to 0.2 mmolL(-1) with a detection limit of 2.1 micromolL(-1) (3sigma). Because of the selective removal of chloroacetyl group from CAP by thiourea, there is little interference by other molecules.
authors.affiliation: Department of Chemistry, Northwest University, Xi'an 710069, China. xfyang@mail.china.com
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D062845:Chloroacetates; D003116:Color; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis; D013696:Temperature; D013890:Thiourea / Q000494:pharmacology*; D013997:Time Factors; D014238:Trichloroacetic Acid / Q000737:chemistry; D014320:Triphenylmethyl Compounds / Q000737:chemistry*
chemical_list: D000081:Acetamides; D062845:Chloroacetates; C518755:N-chloroacetyl parafuchsin; D012997:Solvents; D014320:Triphenylmethyl Compounds; C013874:chloroacetamide; D014238:Trichloroacetic Acid; D013890:Thiourea