Gopi Krishna P, Mary Gladis J, Rambabu U, Prasada Rao T, Naidu G R K
Department of Environmental Sciences, S.V. University, Tirupati 517502, A.P., India.
Talanta. 2004 Jun 17;63(3):541-6. doi: 10.1016/j.talanta.2003.11.032.
A rapid, sensitive and selective method is described for the determination of chromium(VI) in presence of 100-fold amounts of chromium(III) by flame atomic absorption spectrometry (FAAS) in conjunction with coprecipitative preconcentration of its ethyl xanthate complex onto naphthalene. The solid mixture consisting of the chromium(VI) complex together with naphthalene is dissolved in 8.0ml of dimethyl formamide (DMF) and chromium(VI) content was established by FAAS. Calibration graphs were rectilinear over the chromium(VI) concentration in the range 0-200mugl(-1). Five replicate determinations of 20mug of chromium(VI) present in 1.0l of sample solution gave a relative standard deviation of 3.1%. The detection limit corresponding to three times the standard deviation of the blank was found to be 0.5mugl(-1). The developed procedure has been successfully utilized for the estimation of chromium(VI), chromium(total) (after oxidation with bromate) and chromium(III) (by subtracting chromium(VI) content from chromium(total) value contents of several tannery industries.
描述了一种快速、灵敏且选择性好的方法，通过火焰原子吸收光谱法（FAAS）并结合将其乙基黄原酸盐络合物共沉淀预富集到萘上，在存在100倍量铬（III）的情况下测定铬（VI）。由铬（VI）络合物与萘组成的固体混合物溶解于8.0毫升二甲基甲酰胺（DMF）中，并用FAAS测定铬（VI）含量。校准曲线在铬（VI）浓度0 - 200μg l⁻¹范围内呈线性。对1.0升样品溶液中存在的20μg铬（VI）进行五次重复测定，相对标准偏差为3.1%。发现对应于空白标准偏差三倍的检测限为0.5μg l⁻¹。所开发的方法已成功用于估算几家制革工业废水中铬（VI）、总铬（用溴酸盐氧化后）和铬（III）（通过从总铬值中减去铬（VI）含量）。
