在β-环糊精存在下催化动力学光度法测定铬(VI)
Determination of Trace Chromium(Ⅵ) by Catalytic Photometry in the Presence of β-Cyclodextrin
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摘要: 在β-环糊精存在下,根据铬催化溴酸钾氧化罗丹明B的褪色反应,建立了测定痕量铬的新方法.实验结果表明:方法的最大吸收波长为575 nm,铬量在0.007~0.27 mg/L范围内符合比尔定律,表观摩尔吸光系数为1.95×105L.mol-1.cm-1.用于钢样中铬含量的测定,结果与认定值吻合Abstract: A new catalytic spectrophotometric method for the determination of trace chromium(Ⅵ) was developed based on the oxidation of rhodamine B with potassium bromate catalyzed by chromium(Ⅵ) in the present of β-cyclodextrin.The result showed that the maximum absorbance wave length is at 575 nm.The beer’s law is obeyed in the range of 0.007~0.27 mg/L with apparent molar absorption of 1.95 × 105 L·mol-1·cm-1.The proposed method was applied to determination of trace chromium(Ⅵ) in steel samples and the r...