An online liquid chromatography-gas chromatography-mass spectrometric(LC-GC-MS) method was developed for the detection of mineral oil components in recycled and virgin papers.Meanwhile,combined with multivariate statistical analysis,the differences between recycled and virgin papers were analyzed and identified.The mineral oil components in paper samples were extracted with n-hexane-ethanol(1∶1) solution,then analyzed by LC-GC-MS.The chromatograms were subjected to convolution and retention time alignment processing.Principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA) were used to discriminate the recycled and virgin papers,and screen the differential components.Results showed that recycled and virgin papers could be clearly distinguished by multivariate statistical analysis.Compounds including diisopropyl naphthalene isomers,tetramethyl biphenyl isomers,dimethyl biphenyl isomers,isopropylbiphenyl isomers in mineral oil aromatic hydrocarbons(MOAH) fraction,and the compounds containing n-alkanes with carbon atom numbers from 25 to 33 in mineral oil saturated hydrocarbons(MOSH) fraction,were responsible for the chemical difference between recycled and virgin papers.