Abstract: A novel method was proposed for the direct determination of biomarkers, such as n-alkanes, terpanes and steranes in crude oil by GC/MS coupling with backflush cutting technique and micro-fluidic splitter. The variability of 23 n-alkanes, 20 terpanes and 11 steranes was examined and the relative standard deviation (RSD) of retention time were less than 0.02%, while the RSD of peak area of n-alkanes by flame ion detector were in the range of 3.1~6.0%. This method can simultaneously detect mass and flame ion signals with the same retention time, it provides a fast and effective way for the determination of biomarkers in crude oils.

Key words: crude oil, biomarker, backflush cutting, micro fluidic splitter