title: Determination of taurine in human tear fluid by capillary electrophoresis with indirect amperometric detection based on electrogenerated bromine.
abstract: A new method for the determination of taurine was developed based on indirect amperometric detection after capillary electrophoresis. A serial dual-electrode detector comprising an on column Pt film electrode (upstream electrode) and an end column Pt microdisk electrode (downstream electrode) was utilized to conduct the indirect amperometric detection. Bromide is oxidized to bromine at upstream electrode and reduced back to bromide at downstream electrode. Since taurine can react with bromine quantitatively and rapidly, its concentration can therefore be determined by the decrease of the current for bromine reduction at the downstream electrode. Principal experimental parameters governing the analytical performance were investigated and optimized. Under the optimal conditions, taurine can be baseline separated from interfering amino acids and the detection limit of 0.18 μM was obtained with a linear correlation coefficient of 0.999 over the concentration range of 0.5-60 μM. The developed method has been successfully applied in the determination of taurine in human tear fluid. The taurine level obtained was in good agreement with previous reports and recoveries for taurine spiked ranged from 92-95% with relative standard deviations within 4.6%, demonstrating the reliability of the developed method in the determination of taurine in human tear fluid.
authors.affiliation: Department of Water Quality Engineering, School of Power and Mechanical Engineering, Wuhan University, Wuhan, China.|Department of Chemistry, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Fuying
authors.initials: F
authors.lastname: Du
authors.affiliation: Department of Chemistry, The University of Hong Kong, Hong Kong SAR, China.|School of Chemical and Engineering, Jiangsu Normal University, Xuzhou, China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Water Quality Engineering, School of Power and Mechanical Engineering, Wuhan University, Wuhan, China.
authors.forename: Shunan
authors.initials: S
authors.lastname: Cao
authors.affiliation: Department of Chemistry, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Ying-Sing
authors.initials: YS
authors.lastname: Fung
keywords: Amino acids; Capillary electrophoresis; Electrochemical detection; Serial dual-electrode detection