title: Determination of diamondoids in crude oils using gas purge microsyringe extraction with comprehensive two dimensional gas chromatography-time-of-flight mass spectrometry.
abstract: Based on a homemade device, gas purge microsyringe extraction (GP-MSE) of crude oil samples was developed for the first time. As a simple, fast, low-cost, sensitive and solvent-saving technique, GP-MSE provides some outstanding advantages over the widely used sample preparation methods for crude oils such as column chromatography (ASTM D2549). Several parameters affecting extraction efficiency were optimized, including extraction temperature, extraction time, extraction solvent, condensing temperature and purge gas flow rate. With the optimized GP-MSE conditions, several real crude oil samples were extracted, and trace diamondoids were determined using comprehensive two dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS). In total, more than 100 diamondoids were detected and 27 marker compounds were identified and quantified accurately. The limits of detection (LODs, S/N=3) were less than 0.08μg/L for all diamondoids. The relative standard deviation (RSD) was below 8%, ranging from 1.1 to 7.6%. The linearity of the developed method was in the range of 0.5-100.0μg/L with correlation coefficients (R2) more than 0.996. The recoveries obtained at spiking 50μg/L were between 81 and 108% for diamondoids in crude oil samples. The developed method can also be extended to the analysis of other components in crude oils and other complex matrices.
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Wanfeng
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China. Electronic address: shukuizhu@126.com.
authors.forename: Shukui
authors.initials: S
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Liling
authors.initials: L
authors.lastname: Pang
authors.affiliation: Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan 430074, China.
authors.forename: Xuanbo
authors.initials: X
authors.lastname: Gao
authors.affiliation: Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan 430074, China.
authors.forename: Gang-Tian
authors.initials: GT
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Natural Resource of the Changbai Mountain and Functional Molecular of Ministry of Education, Yanbian University, Yanji 133002, China.
authors.forename: Donghao
authors.initials: D
authors.lastname: Li
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D005740:Gases / Q000737:chemistry; D006844:Hydrocarbons, Cyclic / Q000032:analysis*; D057230:Limit of Detection; D010578:Petroleum / Q000032:analysis*
chemical_list: D005740:Gases; D006844:Hydrocarbons, Cyclic; D010578:Petroleum
keywords: Comprehensive two dimensional gas chromatography; Crude oils; Gas purge microsyringe extraction; Time-of-flight mass spectrometry