title: Spectral characteristic investigation on complex of Ni (II) with captopril and its analytical application.
abstract: In this paper, Ni (II) reacting with captopril (CPT) can form complex in alkaline solution and the formed complex has a characteristic absorption peak at 340nm. The absorbance of the Ni-CPT complex increases linearly with the increased concentration of captopril. The study also shows that ammonia has an obvious sensitizing effect on the absorbance. Based on the study, a new method for the determination of captopril is established. Experimental results show that the linear range of this method under optimum condition is 1.0-60mg/L with correlation coefficient, detection limit and precision of 0.9999, 0.31mg/L and 0.87%, respectively. The method used to determine captopril in commercial captopril tablets has a satisfactory result with the recoveries in the range of 99.0-103.6% and the relative standard deviation (RSD) in the range of 0.8-3.7%. We preliminarily study the reaction mechanism and demonstrate that the complex ratio of Ni (II) with captopril is 1:2 and the formation constant is 6.3×10(9).
authors.affiliation: College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China. wxl1651@163.com
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Wei
authors.forename: Liangwei
authors.initials: L
authors.lastname: Du
authors.forename: Dongmei
authors.initials: D
authors.lastname: Li
authors.forename: Qi
authors.initials: Q
authors.lastname: Gong
authors.forename: Lisheng
authors.initials: L
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Lin
mesh_terms: D000042:Absorption; D000641:Ammonia / Q000737:chemistry; D002138:Calibration; D002216:Captopril / Q000032:analysis* / Q000737:chemistry* / Q000652:urine; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D009532:Nickel / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000737:chemistry; D012996:Solutions; D012997:Solvents; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D013997:Time Factors
chemical_list: D007202:Indicators and Reagents; D004364:Pharmaceutical Preparations; D012996:Solutions; D012997:Solvents; D000641:Ammonia; D009532:Nickel; D002216:Captopril