气相色谱法测定固定污染源废气苯系物的方法验证及结果分析

Method Validation and Result Analysis of Gas Chromatography for the Determination of Benzene in Stationary Source Emission

根据HJ1261-2022的要求,对固定污染源废气中苯、甲苯、邻二甲苯、间二甲苯和对二甲苯5种物质的曲线相关系数、检出限、测定下限、精密度和准确度等参数进行实验室方法验证。实验结果表明,校准曲线浓度范围0.5~12.5μumol/mol,5种物质校准曲线的相关系数r≥0.9998;检出限和测定下限分别为0.03~0.07mg/m^(3)和0.12~0.28mg/m^(3);分别对低、中、高浓度进行精密度检查,相对标准偏差为1.35%~5.81%;对有证标准气体重复测试,相对误差-1.20%~1.63%,相对标准偏差1.22%~3.43%,相关系数、检出限、精密度和准确度均满足方法要求。使用1.0mL进样针进样时,隔垫碎屑进入衬管中,导致气相色谱噪音明显增大,建议对气相色谱进样口改进,配备带定量管的六通阀。

According to the requirements of HJ12612022 request,laboratory for stationary Source benzene,toluene,o-xylene,m-xylene and p-xylene of 5 kinds of correlation coefficient,detection limit,lower determination limit,precision and accuracy of the curves such as for laboratory methods validation.The results showed that the concentration range of the calibration curve was 0.5~12.5μmol/mol,and the correlation coefficient of the calibration curve was≥0.9998.The detection limit and the lower detection limit were 0.03~0.07 mg/m^(3) and 0.12~0.28 mg/m^(3),respectively The relative standard deviation(RSD)was 1.35%~5.81%for low,middle and high,and the relative error(RSD)was-1.20%~1.63%for certified standard gases,the relative standard deviation was 1.22%~3.43%,and the correlation coefficient,detection limit,precision and accuracy met the requirements of the method.When 1.O ml injection needle is used,the noise of gas chromatography will increase obviously when the debris of spacer enters the liner.