氧气对空气中甲烷、总烃分析的干扰研究

研究了氧气对空气中甲烷、总烃分析时的干扰。得出，载气的纯度很高时使用GDX-502填充柱可以将甲烷峰和氧峰完全分离，甲烷和总烃和分析可不受氧峰干扰，气样中氧气浓度低于17％时氧峰可忽略，低于12．5％时氧峰消失。氢火焰离子化检测器不能检出氧气，氧峰仅为干扰峰，在一定的色谱条件下，干扰峰即氧峰和气样中的氧气浓度成正比关系。当气样中氧气浓度小于28．7％时，总烃值峰值等于甲烷测试时氧峰和各烃峰之和，当氧气浓度大于28．7％时，不能用国标气相色谱法测试总烃，总烃值应等于总烃峰值值减去该气样的氧值。

Research on the Oxygen's Disturbance to the Analysis of Methane and Total Hydrocarbon

The oxygen＇ s disturbance to the analysis of methane or total hydrocarbon in the air or gas was studied. The peak of methane and oxygen could be separate completely with high - purity carrier gas use GDX--502 chromato- graphic column, and the analysis of methane and total hydrocarbon could not be disturbed by oxygen peak ; When the concentration of oxygen below 17% in the sample the oxygen peak could be ignored, while under 12. 5% , the peak of oxygen disappeared; The oxygen could not be detected by the FID, so the oxygen peak was only a interfering peak. The oxygen peak rised proportionately to the concentration of oxygen under certain chromatographic condition, the total hydrocarbon peak value was equal to sum of oxygen peak and various hydrocarbons peak if the concentration of oxygen was under 28. 7%, if larger than this concentration, we could not test the total hydrocarbon with GB method, because the total hy_ drocarbon value should equal to total hydrocarbon peak value subtracts the oxygen value of this gas.