Gao R M, Zhao Z Q, Zhou Q Z, Yuan D X
Hygienic Chemistry Section, Department of Public Health, Hebei Medical College, Shijiazhuang City, Hebei Province, P.R. of China.
Talanta. 1993 May;40(5):637-40. doi: 10.1016/0039-9140(93)80269-w.
A new spectrophotometric determination method of hexavalent chromium in waste water and plating baths is described based on the oxidation of beryllon III by chromium(VI) in 0.02M sulphuric acid medium. The decrease in the absorbance of beryllon III was measured at 482 nm with an apparent molar absorptivity of 5.15 x 10(4)1.mole(-1).cm(-1). Beer's law was obeyed for chromium(VI) over the range 0-25 mug/25 ml. After the oxidation of Cr(III) to Cr(VI) by ammonium persulphate, total chromium can be determined. Therefore, chromium(III) can be calculated by subtracting chromium(VI) from total chromium. The detection limit is 0.015 and 0.020 mug/25 ml for chromium(VI) and total chromium, respectively. A sensitive spectrophotometric method for trace Cr(III) and Cr(VI) in waste water and plating baths was developed with good precision and accuracy. The reaction is also discussed.
本文描述了一种新的分光光度法，用于测定废水和电镀液中的六价铬。该方法基于在0.02M硫酸介质中，六价铬对铍试剂III的氧化作用。通过在482nm处测量铍试剂III吸光度的降低来进行测定，其表观摩尔吸光系数为5.15×10⁴L·mol⁻¹·cm⁻¹。在0-25μg/25ml范围内，六价铬符合比尔定律。用过硫酸铵将三价铬氧化为六价铬后，可测定总铬。因此，通过从总铬中减去六价铬即可计算出三价铬的含量。六价铬和总铬的检测限分别为0.015和0.020μg/25ml。该方法为废水和电镀液中痕量三价铬和六价铬的测定提供了一种灵敏的分光光度法，具有良好的精密度和准确度。文中还对该反应进行了讨论。
