废气中总烃、甲烷和非甲烷总烃测定因素探讨

Discussion on Determination Factors of Total Hydrocarbons,Methane and Non Methane Total Hydrocarbons in Waste Gas

根据《固定污染源废气总烃、甲烷和非甲烷总烃的测定气相色谱法》(HJ 38-2017),选择不同的采样容器及样品的保存时间,比较总烃、甲烷和非甲烷总烃在不同采样器中检测结果随样品保存时间的变化。实验结果表明,采用注射器作为采样容器,样品测试浓度随保存时间增加而快速减小,样品需在4 h内分析,检测结果才具有可靠的准确度,实际监测工作中,从样品采样到实验室分析,一般情况下4 h内不能完成分析;采用气袋作为采样容器,样品测试浓度随保存时间增加而相对稳定,样品可在2 d内分析,检测结果具有可靠的准确度,更能满足方法的要求,在实际工作中更具有操作性。

According to the Gas Chromatography Method for the Determination of Total Hydrocarbons,Methane,and Non methane Total Hydrocarbons in Waste Gas from Fixed Pollution Sources(HJ 38-2017),different sampling containers and sample storage times were selected to compare the detection results of total hydrocarbons,methane,and non methane total hydrocarbons in different samplers with changes in sample storage time.The experimental results showed that using a syringe as the sampling container,the sample testing concentration rapidly decreased with increasing storage time.The sample needed to be analyzed within 4 h to have reliable accuracy in the detection results.In actual monitoring work,from sample sampling to laboratory analysis,analysis cannot be completed within 4 h in general.Using an air bag as the sampling container,the sample testing concentration was relatively stable with increasing storage time.The sample can be analyzed within 2 days,and the testing results had reliable accuracy,which better met the requirements of the method and was more operational in practical work.