title: Catalysis reaction between sodium 1,2-naphthoquinone-4-sulfonate and hydroxyl ion using captopril as catalyzer and determination of captopril.
abstract: A novel and simple spectrophotometric method for the determination of Captopril with sodium 1,2-naphthoquinone-4-sulfonate is established in this paper. The detailed reaction mechanism is proposed and discussed. It is based on the fact that captopril can catalyze the reaction between sodium 1,2-naphthoquinone-4-sulfonate and hydroxyl ion to form 2-hydroxy-1,4-naphthoquinone in buffer solution of pH 13.00. Beer's law is obeyed in a range of 0.64-80 mugmL(-1) at the maximal absorption wavelength of 442 nm. The equation of linear regression is A=0.05815+0.00589C (mugmL(-1)), with a linear regression correlation coefficient of 0.9981. The detection limit is 0.3 mugmL(-1), R.S.D. is 0.77% and the recovery rate is in range of 96.0-103.8%. Furthermore, the method has been validated and successfully applied to the determination of captopril in pharmaceutical samples.
authors.affiliation: College of Chemistry and Environmental Science, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, PR China.
authors.forename: Linxiao
authors.initials: L
authors.lastname: Gao
authors.forename: Lingli
authors.initials: L
authors.lastname: Wu
authors.forename: Quanmin
authors.initials: Q
authors.lastname: Li
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis* / Q000737:chemistry; D002216:Captopril / Q000032:analysis* / Q000737:chemistry; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D013058:Mass Spectrometry; D009285:Naphthoquinones / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D013055:Spectrophotometry, Infrared
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D006878:Hydroxides; D009285:Naphthoquinones; C011942:1,2-naphthoquinone-4-sulfonate; C031356:hydroxide ion; D002216:Captopril; C005090:lawsone