Some problems often occur in the analysis for petroleum samples by GC-MS.When high content wax composes oil samples,the n-alkanes in saturated fraction would disturb the mass chromatograph distribution and result of biomarkers.The n-alkanes can be removed from the saturated fraction by complexation,which n-alkanes react with carbamide supersaturated in methanol solution.Nevertheless,levels of the complexation can also affect on the mass chromatograph distribution and result of biomarkers.This paper discusses these problems and measures.
