title: Light-absorption ratio variation approach to determination of nickel (II) in ng/ml level with 1, 5-di(2-hydroxy-5-sulfophenyl)-3-cyanoformazan.
abstract: The light-absorption ratio variation approach (LARVA) has been described and applied to the quantitative detection of ultramicro amounts of Ni by spectrophotometry, which raises notably the detection sensitivity. The complexation between 1, 5-di(2-hydroxy-5-sulfophenyl)-3-cyanoformazan (DSPCF) and Ni(II) at pH 9.11 was investigated and the binary complex was characterized by the spectral correction technique. Results have shown that deltaAr-1 (deltaAr--light-absorption ratio variation) is linear in the range of Ni(II) between 5 and 200 ng/ml. The limit of detection (3sigma) of Ni(II) is only 1.3 ng/ml. The complexation is selective in the presence of fluoride, hexametaphosphate, ethylene diamine tetraacetate and thioglycollic acid. It has been applied to analysis of water quality with satisfactory results.
authors.affiliation: School of Environmental Science and Engineering, Tongji University, State Key Laboratory of Pollution Control and Resource Reuse, Shanghai 200092, People's Republic of China. hwgao@mail.tongji.edu.cn
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Gao
authors.forename: Si-Qing
authors.initials: SQ
authors.lastname: Xia
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Wang
authors.forename: Jian-Fu
authors.initials: JF
authors.lastname: Zhao
mesh_terms: D004784:Environmental Monitoring; D005562:Formazans / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008027:Light; D009532:Nickel / Q000032:analysis*; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D014873:Water Pollutants / Q000032:analysis*
chemical_list: C488404:1,5-di(2-hydroxy-5-sulfophenyl)-3-cyanoformazan; D005562:Formazans; D014873:Water Pollutants; D009532:Nickel