工作场所空气中亚硝酸盐测定方法的对比研究

Comparative study of nitrite determination method of workplace air

目的对顶空气相色谱法和离子色谱法测定空气中亚硝酸盐进行对比研究。方法分别采用顶空气相色谱法和离子色谱法对方法的灵敏度、准确度、精密度进行综合对比研究;同时将样品分为两组,根据2种方法的要求分别进行测定,将测定结果进行比较。结果顶空气相色谱法的测定范围为0.56～20.0μg/ml,检出限为0.56μg/ml,相对标准偏差为0.77%～2.27%,加标回收率为95.2%～99.1%;离子色谱法的测定范围为0.50～30.0μg/ml,检出限为0.50μg/ml,相对标准偏差为0.38%～1.03%,加标回收率为97.0%～101.0%。2种方法测定空气中亚硝酸盐标准物质结果均在标示值范围内,2种方法对一组样品进行配对测试,结果经t检验分析,差异无统计学意义。结论顶空气相色谱法和离子色谱法分析性能基本一致,均满足空气中亚硝酸盐含量的分析,适合批量样品分析。样品前处理简单省时,测定速度快,灵敏度高,干扰少。

[ Objective ] To compare the 2 methods of headspace gas chromatography and ion chromatography for determination of ni- trite in the air. [ Methods ] The sensitivity, accuracy, precision between headspace gas chromatography and ion chromatography were compare. The samples were divided into 2 groups,and then determined by headspace gas chromatography and ion chromatography, respectively according to the different requirement of the 2 methods. Finally, the results were compared. [ Results ] The measure- ment range of headspace gas chromatography was 0. 56-20. 0 μg/ml, the detection limit was O. 50 μg/ml; the RSD was 0.77% -2. 27% ,the recovery rate was 95.2% -99.1% ;while the measurement range of ion chromatography was 0.50-30.0 μg/ml and the detection limit was 0.50 μg/ml,the RSD was 0.38% -1.03% ,the recovery rate was 97.0% -101.0%. The values of the 2 method were in the range of the marked value ;There was no statistical difference for t test between the sample results of 2 methods. [ Conclusion]The analytical performance for headspace gas chromatography is basically consistent with ion chromatography. The two methods are satisfactory to the determination of nitrite in the air, and are suitable for batch sample analysis with characteristics of simple sample preparation, rapid, high sensitivity and less interference.