Gas chromatograph for detecting epoxy compounds in petroleum at gas stations

Determination of petroleum components and range:

Gas chromatograph for detecting epoxy compounds in petroleum at gas stations

Method Summary：

Analysis of benzene and toluene: Start valve in "OFF" state（Refer to Figure 1A），The sample with internal standard (2-hexanone) added is introduced into the system. The sample first passes through a TCEP pre cut column, and C9 and non aromatic hydrocarbons with boiling points less than C9 flow out of the pre column and are directly vented. Switch the valve to the "ON" state before the benzene flows out（See Figure 1B），Blow back the pre column to transfer the retained components to the WCOT analysis column, and benzene, toluene, and internal standard flow out of WCOT in boiling orderanalysisUse FID for column detection. Immediately switch the valve to the "OFF" state after the internal standard substance flows out（Refer to Figure IC），Transfer the remaining components (C)8And C8The above aromatic hydrocarbons and non aromatic hydrocarbons above C10 and C10 were backblown out of the WCOT column and detected by FID.

Aromatic hydrocarbon analysis: Direct venting of non aromatic hydrocarbons, benzene, and toluene with less than C12 after flowing out of the pre column（Refer to Figure 1A），Switch the valve to "ON" before ethylbenzene flows out（See Figure 1B），Transfer the retained components to the analysis column WCOT, and the internal standard and C8 aromatic hydrocarbons flow out in boiling order for FID detection. When ortho xylene flows out, immediately blow back the analytical column（Refer to Figure IC）Blow C9 and above aromatic hydrocarbons back out of the chromatographic column and enter FID detection.

Analysis of oxygen-containing compounds: Start valve is in the "OFF" state（Refer to Figure 1A），Add internal standard ethylene glycol dimethyl ether (DME) to the sample introduction system, and the sample is first passed through the TCEP pre cut column and directly emptied. Switch the valve between methyl cyclopentane and methyl tert butyl ether to the "ON" state（See Figure 1B），Blow back the pre column to transfer the retained components to the WCOT analysis column, and the oxygen-containing compounds flow out of WCOT in boiling orderanalysisUse FID for column detection. Immediately switch the valve to the "OFF" state after the outflow of tert amyl methyl ether（Refer to Figure IC），Blow the remaining components back out of the WCOT column for FID detection.