Quick Determination of Twelve Additives in Motor Gasoline by Comprehensive Two-Dimensional Gas Chromatography

A method based on the comprehensive two-dimensional gas chromatography (GC×GC) was established for determination of the twelve additives including three ester additives, six aniline additives and three metal-organic additives in motor gasoline. The gasoline sample was injected directly, separated by 1^st dimensional HP-INNOWAX chromatographic column, and then pulsed out to 2^nd dimensional DB-17ms chromatographic column for further separation. The target analytes were detected by FID. Internal standard method was applied for quantification, and matrix matching method was used to prepare mixed standard solution series. As results showed that the linearity range of standard curves of twelve additives was found same in the range of 50-2 000 mg·L^-1, with correlation coefficients all above 0.999 0 and detection limits (3S/N) in the range of 12.87-24.82 mg·L^-1. The spiked recovery tests were made on blank gasoline samples at three concentration levels, giving recoveries in the range of 94.4%-118%, with RSDs (n=6) of determined values in the range of 0.44%-4.0%. Analytical results of ester additives, aniline additives, metal elements in two actual samples obtained by the proposed method were compared to those of GB/T 32693-2016, GB/T 33646-2017 and ICP-AES, and results of F-test and t-test at 95% confidence level showed that there was no significant difference in precision between this method and other three methods; the results using this method were no significantly different with GB/T 33646-2017 and ICP-AES, but significantly different between GB/T 32693-2016 and this method due to the lower measurement of GB/T 32693-2016.