连续流动分析法测定水质中六价铬的方法研究

Determination of hexavalent chromium in water by air-segmented continuous flow-analysis

〔目的〕研究连续流动分析法检测水质中六价铬的方法。〔方法〕采用BRAN +LUEBBEAA3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生成一种紫红色络合物 ,在 5 5 0nm处检测。〔结果〕方法的相关性好(r>0 .9990 ,n =5 ) ,标准及样品测定的相对标准偏差分别为RSD≤ 2 .31%、RSD≤ 4 .39% ,检出限为 0 .82 μg/L(EPA论证值 ) ,回收率范围 93.6 %～ 10 5 .4 %。与分光光度法对照表明 ,其结果无显著性差异。〔结论〕方法快速、准确、灵敏度高。

睴bjective〕To study a method for hexavalent chromium in water by air-segmented continuous flow-analysis.〔Methods〕BRAN+LUEBBE AutoAnalyzer 3 was selected.The automated procedure for the determination of hexavalent chromium in water depends on the reaction of diphenylcarbazide with hexavalent chromium in an acid medium to produce a reddishpurple colour which can be measured at 550nm.〔Results〕This methed has a good relativity ( r >0.9990, n =5),the RSD% of standards and samples were less than 2.31% and 4.39% respectively,the spike recovery rate of the samples was between 93.6% and 105.4%,the method detection limit was 0.82μg/L(determined according to EPA procedure pt.136,app.B).Comparing with the results by spectrophotometry,there was no significance.〔Conclusions〕 The method is rapid,accurate and highly sensitive.