基于改造氨氮模块的连续流动分析仪检测水中六价铬含量

Determination of Hexavalent Chromium Content in Water by Continuous Flow Analyzer Based on Modified Ammonia Nitrogen Module

目的:将连续流动分析仪氨氮模块进行简单改造,用于检测水中六价铬含量。方法:采用SKALAR San++型连续流动分析仪,根据六价铬在酸性条件下与二苯碳酰二肼反应生成一种紫红色络合物,在540 nm处检测六价铬含量。结果:六价铬在0~0.2 mg·L^(-1)具有良好的线性关系,相关系数为0.9993;检出限为0.001 mg·L^(-1);相对标准偏差<3%,回收率在95.1%~103.0%;本法和国标二苯碳酰二肼分光光度法比较无显著性差异。结论:改装后的连续流动分析仪测定水中六价铬具有检测速度快、准确度和灵敏度高、对环境污染小的特点,适用于大批量水样的分析,同时减少了实验室二次采购仪器的成本。

Objective:The ammonia nitrogen module of continuous flow analyzer was simply modified to detect hexavalent chromium content in water.Method:SKALAR SAN++continuous flow analyzer was selected.According to the reaction of hexavalent chromium with diphenylcarbazide under acidic conditions to form a purplish red complex,and the content of hexavalent chromium was determined at 540 nm.Result:This methed has a good relativity between 0 mg·L^(-1)and 0.2 mg·L^(-1).The correlation coefficient was 0.9993 and the detection limit was 0.001 mg·L^(-1).The relative standard deviation was<3%,and the recovery rates was 95.1%~103.0%.It was not significant difference compared with standard method used with diphenylcarbazide for spectrophotometry.Conclusion:The modified continuous flow analyzer method for the determination of hexavalent chromium in water has the characteristics of fast detection speed,high accuracy and sensitivity,and little environmental pollution.It can be applied to analyse enormous water samples and which has saved the costs of making the second purchase of equipment for laboratories.