title: Quantitative analysis of thiols in consumer products on a microfluidic CE chip with fluorescence detection.
abstract: A microchip CE-based method for the quantification of the thiols mercaptoethanoic acid (MAA) and 2-mercaptopropionic acid (2-MPA) in depilatory cream and cold wave lotions was developed. The thiols were first derivatized with the fluorogenic reagent ammonium-7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate (SBD-F). The derivatives were separated within only 20 s by microchip CE and detected by their fluorescence. Conventional CE with diode array detection and LC with fluorescence detection were used for validation. The internal standard 3-mercaptopropionic acid (3-MPA) provided RSDs of multiple injections of only 4% or less for the MCE approach. LOD is 2 microM, LOQ 6 microM, and the linear range comprises nearly three decades of concentration starting at the LOQ.
authors.affiliation: Chemical Analysis Group and MESA, Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
authors.forename: Tobias
authors.initials: T
authors.lastname: Revermann
authors.forename: Sebastian
authors.initials: S
authors.lastname: Götz
authors.forename: Uwe
authors.initials: U
authors.lastname: Karst
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000032:analysis*; D003358:Cosmetics / Q000032:analysis*; D046209:Electrophoresis, Microchip / Q000379:methods; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D005464:Fluorobenzenes / Q000737:chemistry; D044085:Microfluidics; D013438:Sulfhydryl Compounds / Q000032:analysis*
chemical_list: D003358:Cosmetics; D005456:Fluorescent Dyes; D005464:Fluorobenzenes; D013438:Sulfhydryl Compounds; C037802:7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate; D015097:3-Mercaptopropionic Acid; C023884:thiolactic acid