title: [Fluorescence quenching reaction of tetracaine hydrochloride with erythrosine and their analytical applications].
abstract: In Britton-Robinson (BR) buffer solution at pH 4.0, erythrosine (ET) reacts with tetracaine hydrochloride (TA x HCl) to form an ion association complex that quenches the fluorescence of erythrosine and has a compound ratio of 1 : 1. The measurement wavelength of fluorescence quenching was located at lambda(ex)/lambda(em) = 525 nm/556 nm. The linear range for TA x HCl is from 0.28 microg x mL(-1) to 4.8 microg x mL(-1), and its detection limit is 0.083 microg x mL(-1). The influence of coexisting substance was also inspected, and the result shows that this method has a better selectivity. Therefore, a new fluorospectrophotometry, being high sensitive, sample and rapid, was developed to determinate TA x HCl at trace amounts. The method has been applied to the determination of TA x HCl in human serum and urine samples with satisfactory results. In this study, the spectral characteristics and the optimum reaction conditions were discussed with quantum chemistry AM1 method.
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
authors.forename: Ming-You
authors.initials: MY
authors.lastname: Qin
authors.forename: Shao-Pu
authors.initials: SP
authors.lastname: Liu
authors.forename: Zhong-Fang
authors.initials: ZF
authors.lastname: Liu
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Hu
mesh_terms: D004923:Erythrosine / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013696:Temperature; D013748:Tetracaine / Q000032:analysis* / Q000737:chemistry
chemical_list: D013748:Tetracaine; D004923:Erythrosine