一种检测皮革中六价铬含量的双波长可见分光光度法

Determination of Hexavalent Chromium Content in Leather by Dual-wavelength Visible Spectrophotometry

探讨了由光学检测本身所产生的干扰因素对现行国家标准方法(GB/T 22807-2008)的影响,建立了一种检测皮革制品中六价铬含量的双波长可见分光光度法。本方法基于国家标准方法进行样品预处理和显色,光谱分析是采用在540、650nm 2个波长处分别测定显色组及对照组样品的吸光度,即:用双波长法处理来定量计算六价铬含量。结果表明:样品萃取液进行平行测定时在650nm处吸光度的误差可达8.0%,用单波长的计算方法其平行试验结果之间的相对误差可达5.4%,而本方法的相对误差仅为0.5%。同时本方法能有效地校正扣除萃取液颜色和基线漂移的影响,且检测限可达1.98mg/kg。方法检测结果的准确性好、精确性高,适用于皮革制品中微量六价铬含量的检测。

The effect of the interference factors of optical detection itself on the current national standard method （ GB/T 22807 -2008 ） were discussed. The method of determination of hexavalent chromium content in leather by dual - wavelength visible spectrophotometry was established. It was applied for pretreatment and color development. The dual - wavelength （ 540nm and 650nm） were used for measuring absorbance of chromogenic group and control group, namely measuring the hexavalent chromium content of the product. The results show that the relative error of absorbance （ at 650nm） of Sample extract solution for parallel de- termination is up to 8.0%. The relative error between two measurements is 5.4% when using the single wavelength method. How- ever, the relative error is only 0.5% with the dual -wavelength method. Meanwhile, The method can efficiently reduce the errors caused by the color fading of leather sample and the baseline drifting of instrument, and the detection limit is 1.98 mg/kg. The test results of the dual - wavelength method is good in accuracy and high in precision, which is suitable for determining the hexa-valent chromium content in leather products.