不同酸介质下连续流动分析仪测定水样中六价铬的探究

Determination of Hexavalent Chromium in Water by Continuous Flow Analyzer in Different Acid Media

采用德国seal公司AA3HR型连续流动分析仪测定水样中六价铬,在不同酸介质下对测定结果的影响进行了研究,结果表明,在高氯酸、硝酸、磷酸及醋酸等高强酸和弱酸介质中的标准曲线线性、检出限、精密度虽然优于环境标准方法,但有证标准物质准确率低,样品加标回收率不能满足方法要求;在硫酸、盐酸及硫磷酸等中强酸介质中,标准曲线线性好,检出限低,精密度和准确度较高,加标回收稳定,各项指标均能满足环境标准方法要求。推荐在分析过程中可用硫酸、盐酸和硫磷酸相互替代使用。

In this paper,the AA3HR continuous flow analyzer of German Seal company was used to determine hexavalent chromium in water Under different acid media,the influence on the determination results was studied.The results showed that the linearity,detection limit and precision of the standard curve in perchloric acid,nitric acid,phosphoric acid and acetic acid and other high and weak acid media were better than the environmental standard method,but the accuracy of certified reference materials was low,and the recovery rate of sample spiking could not meet the requirements of the method;In medium to strong acid media such as sulfuric acid,hydrochloric acid,and thiophosphoric acid,the standard curve had good linearity,low detection limit,high precision and accuracy,stable recovery after addition,and all indicators could meet the requirements of environmental standard methods.It is recommended to use sulfuric acid,hydrochloric acid and thiophosphoric acid as substitutes in the analysis process.