【摘要】 六价铬[Cr（Ⅵ）]在水环境中有严重的毒性和迁移性，尤其工业过程中的高浓度Cr（Ⅵ）,对环境和人体健康有严重的危害。建立一种准确、快速且实用的高浓度Cr（Ⅵ）溶液测定方法尤为重要。描述了一种基于光程优化的紫外可见分光光度法直接测定溶液的新方法，该方法聚焦于不同光程条件下，测定Cr（Ⅵ）溶液的浓度范围和灵敏度研究。结果表明，通过改变光程（1, 5, 10, 30, 50, 100 mm）, Cr（Ⅵ）溶液的线性浓度测定范围增加到1 500 mg·L^-1(国标方法为1 mg·L^-1);光程从1 mm增加到100 mm,测定灵敏度增加了100.3倍(从0.001 6 L·mg^-1增加到0.161 5 L·mg^-1)。同时，进行了光程优化方法的建立，在保证准确度的前提下，使得不同浓度在不同光程的测定条件下具有最高的灵敏度。研究结果表明，在Cr（Ⅵ）与三价铬[Cr（Ⅲ）]、铁离子[Fe（Ⅲ）]、铜离子[Cu（Ⅱ）]、镍离子[Ni（Ⅱ）]以一定比例共存的条件下，该方法有较好的抗离子干扰性能，且测定结果的准确度几乎不受温度变化影响（5～30℃）,并成功地将该方法应用于实际电镀废水样品中高浓度Cr（Ⅵ）的分析。与其他常见的Cr（Ⅵ）溶液测定方法相比，该方法显示出更宽泛的线性浓度范围(0.003 96～1 500 mg·L^-1)、更高的高浓度Cr（Ⅵ）溶液分析准确度和很短的测定时间（1.5 min）。该方法在工业过程中Cr（Ⅵ）溶液的污染控制和环境分析监测方面具有良好的应用前景。更多还原

【Abstract】 Cr（Ⅵ） has severe toxicity and mobility in the environment, especially for high-concentration Cr（Ⅵ） in the industrial process. It is important to developing an accurate and practical method for its determination. This study described a new direct spectrophotometry for determining Cr（Ⅵ） solution based on optical path optimization. The method focused on the high-concentration and determination sensitivity of the Cr（Ⅵ） solution under different optical paths. The results showed that the linear determination concentration of Cr（Ⅵ） solution increased to 1 500 mg·L^-1 by changing the optical paths（1, 5, 10, 30, 50, 100 mm）, and the determination sensitivity increased by 100.3 times(from 0.001 6 to 0.161 5 L·mg^-1) linearly from 1 to 100 mm. Based on the highest sensitivity, the optical path optimization method was studied on the premise of ensuring accuracy. Different concentrations have the highest sensitivity under different optical path measurement conditions. In addition, the results showed that under the condition of coexistence of Cr（Ⅵ） with trivalent Cr（Ⅲ）, Fe（Ⅲ）, Cu（Ⅱ） and Ni（Ⅱ） in a certain proportion, the method had good anti-ion interference performance, and the accuracy of the determination results was hardly affected by the change of temperature（5～30 ℃）. The method was also successfully applied to analyse high-concentration Cr（Ⅵ） in practical electroplating wastewater samples. Moreover, compared with other common Cr（Ⅵ） determination methods, this method showed a wider Cr（Ⅵ） concentration linear range(0.003 96～1 500 mg·L^-1), higher analytical accuracy of high-concentration Cr（Ⅵ） solutions, and rapid determination time（1.5 min）. Therefore, this method had good application prospects in the industrial process for environmental analysis and monitoring of the Cr（Ⅵ） solution.更多还原