液液萃取-GC-MS法测定水中硝基苯质量控制指标研究

采用液液萃取–气相色谱–质谱法测定水中硝基苯,通过统计全国多家实验室的测定数据,对平行样测定结果相对偏差、空白加标回收率、样品加标回收率、空白加标回收率相对偏差及样品加标回收率相对偏差5个质控指标进行分析,得出质控指标评价标准。在概率P,γ均为0.90时,平行样测定结果允许最大相对偏差应控制在11.0%;当空白加标浓度为0.2～30μg/L时,回收率控制范围为59%～113%;当样品未检出、加标浓度在0.25～50μg/L时,样品加标回收率控制范围为56%～110%;空白加标、样品加标回收率最大相对偏差应分别控制在10.0%和11.1%。在概率P和γ均为0.95时,平行样测定结果允许最大相对偏差应控制在13.5%;当空白加标浓度为0.2～30μg/L时,回收率的控制范围为50%～122%;当样品未检出、加标浓度在0.25～50μg/L时,样品加标回收率控制范围为49%～117%;空白加标、样品加标回收率最大相对偏差应分别控制在12.6%和14.6%。

Research on Quality Control Index for Determination of Nitrobenzene in Water by GC-MS After liquid-liquid Extraction

Five indexes of quality control for determination of nitrobenzene by GC-MS after liguid-liquid extraction were given by evaluating datas collected from a few labs national-widely, including the relative deviation of the duplicates detection results, the recoveries and the relative deviation of the blank sample with standard addition, the recoveries and the relative deviation of the real sample with standard addition. The quality control indexes were produced as the probability of both P and γ, were 0.90, the maximum relative deviation of the detection results should be within 11.0%; the blank recoveries should be within 59%-113% as the addition concentration was 0.2-30 μ g/L; the sample recoveries should be within 56%-110% when the nitrobenzene was not detected in all the samples and the addition concentration was 0.25-50 μ g/L; the maximum relative deviation of the blank sample with standard addition should be within 10.0%, and the maximum relative deviation of sample with standard addition should be within 11.1%. When the probability of both P and y were 0.95, the maximum relative deviation should be within 13.5%; the blank recoveries should be within 50%-122% as the addition concentration was 0.2- 30 μ g/L; the sample recoveries should be within 50%-122% as the nitrobenzene was not detected in all the samples and the addition concentration was 0.25-50 μ g/L; the maximum relative deviation of the blank sample with standard addition should be within 12.6%, and the maximum relative deviation of the sample with standard addition should be within 14.6%.