Analysis of Benzene Compounds in Gasoline by Longyan Gas Chromatography

Analysis of Benzene Compounds in Gasoline by Longyan Gas Chromatography

Shanghai Xuansheng Scientific Instrument Co., Ltd，A chromatographic analysis system launched--GC-7890typeGasoline analysisChromatography instrument, thisThe system completes the analysis of oxygen-containing compounds such as alcohols, ethers, and benzene in gasoline, and its process design is * SH/T0663 "Determination of Certain Alcohols and Ether Oxygenated Compounds in Gasoline"、SH/T0693 "Determination of Aromatic Hydrocarbons in Gasoline"、GB17930-2006 "Gasoline for Vehicles"、The provisions of GB 18351-2004 "Ethanol Gasoline for Vehicles".The analysis software equipped with the instrument directly calculates various national standard required result expressions such as volume fraction, mass fraction, volume percentage, and mass percentage, and has density conversion function. It is a domestically equipped and professional gasoline analysis system

Gasoline is used to improve the environmental pollution caused by lead in car emissions. Adding ethers, alcohols, and other oxygen-containing compounds to gasoline can increase octane rating and reduce volatility. The type and concentration of oxygen-containing compounds added are specified and should be adjusted to ensure that the quality requirements of commercial gasoline are met..

Instrument configuration:

GC-7890 Gas chromatograph hostHydrogen flame detector（FID）、 Valco automatic ten way valve blowback and reset system、Capillary injectiondevice、eighteenStep program temperature rise, intelligent rear door openingProtection against gas and air leaks;chromatographic column：Pre cut column 0.56m × 0.38mm stainless steel column 20% TCEP/Chromosorb P (AW) 80-100eye，Analysis columnHP-1 (WCOT) 30m × 0.32mm × 3 μ m, cross-linked methyl silicone quartz capillary column.

Method Summary：

Analysis of Benzene Compounds in Gasoline by Longyan Gas ChromatographyAnalysis of benzene and its derivatives: 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, including benzeneBTEX (Benzene, Toluene, Ethylbenzene, Xylenes)Flow out WCOT in boiling point order with the internal standardanalyzeUse 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: Analyze non aromatic hydrocarbons, benzeneBTEX (Benzene, Toluene, Ethylbenzene, Xylenes)After flowing out of the pre column, it is directly emptied（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 neighboring twoBTEX (Benzene, Toluene, Ethylbenzene, Xylenes)After outflow, immediately blow back the analysis 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 orderanalyzeUse 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.

Chromatographic operating conditions:

Determination of components and range: