Determination of Acidolysis Hydrocarbons in Oil/Gas Geochemical Exploration Samples by Gas Chromatography

A method for the determination of acidolysis hydrocarbons in oil/gas geochemical exploration samples by autosampler-GC-FID using multiple acidolysis devices was developed based on the improvement of traditional single set acidolysis equipment. The optimization of the main analytical conditions and quality control are also discussed in detail in this paper. The acidolysis of samples was carried out in vacuum in a 40℃ water bath for 10 min. The emitted gases of acidolysis hydrocarbons were stored in sealed bottles for gas chromatography determination. The detection limit of this developed method was 0.007-0.057μL/kg with relative standard deviation(RSD) of 0.8%-1.1%. The relative deviation(RD) of two independent tests for 105 samples varied from 0.01% to 19.66% with an average of 7.81%(calculated by methane). This proposed method is suitable for the determination of acidolysis hydrocarbons in oil/gas geochemical exploration samples and has been successfully used in natural gas hydrate prospecting.