With the continuous rise of liquefied petroleum gas prices, some liquefied petroleum gas filling units have illegally added dimethyl ether to it. Such behavior may bring direct or indirect harm to people's and consumers' lives and production practices. Therefore, regulatory authorities strictly prohibit the addition of dimethyl ether to liquefied petroleum gas. This article summarizes the previous work on the detection methods of dimethyl ether in liquefied petroleum gas, laying the foundation for the improvement and determination of analytical and detection standards for dimethyl ether in liquefied petroleum gas.

Introduction to analysis methods: TCD detectors are mostly used to analyze the composition of liquefied gas. They are made based on the principle that the thermal conductivity changes when other gaseous substances are mixed into the carrier gas. The greater the difference in thermal conductivity between the carrier gas and the sample, the greater the detector response value. The main components of liquefied gas are C3 and C4, and using H2 and He as carrier gases can provide * results. But He has a high price in China, so H2 is commonly used as a carrier gas. H2 has high thermal conductivity and can use larger bridge currents, which is beneficial for improving sensitivity. H2 not only has a wide linear range but also has low viscosity, making it suitable for rapid analysis. Therefore, H2 is the most ideal carrier gas under these analysis conditions.

Analysis spectrum of dimethyl ether in liquefied gas: (￠ 3 * 6m)


Peak number, peak name, retention time, peak area, and content
1 Air+Methane 1.282 234668.750 1175885.250 36.3242
2 Ethane+Ethylene 1.693 7564.802 48259.895 1.4908
3 propane+propylene 2.570 36463.773 360678.625 11.1417
4 Dimethyl ether 3.227 55590.910 719608.125 22.2294
5 Isobutane 4.087 27451.688 421956.219 13.0346
6 Isobutene 5.035 5039.755 75082.484 2.3194
7 n-butane 5.490 14166.147 246433.359 7.6126
8 Butene-2 6.078 4123.336 73754.680 2.2783
9. Male-2 6.658 2414.356 47309.918 1.4614
10 Methanol 7.532 338.524 11687.250 0.3610
11 Isopentane 10.793 1441.571 395109.18 1.2205
12 n-pentane 13.707 594.716 17031.439 0.5261

According to national standards, GC-2020 gas chromatograph is used to detect liquefied gas components and dimethyl ether mixed in liquefied gas. The analysis time is within 15 minutes, providing users with accurate and rapid detection methods, as well as good training and learning opportunities.