Abstract: Internal standard method is developed for the determination of the content of benzene,naphthalene,α-methylnaphthalene and β-methylnaphthalene in coal tar by using gas chromato-graphy,which employs a DB-5 capillary column and with DMF used as the solvent,and n-dodecane as internal standard.The results show that every composition in coal tar could be well separated.The experimental results are accurate and precise.The recovery rates are 95.5%~103.3%,and the relative standard deviations are between 1.72%~7.75%.

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