This method covers the determination of butadiene 1,3 purity and impurities such as propane, propylene, isobutane, n butane, butene 1, isobutylene, propadiene, trans butene 2, cis butene 2, butadiene 1,2, pentadiene 1,4 and methyl, dimethyl, ethyl, and vinyl acetylene in polymerization grade butadiene by gas chromatography. Impurities including butadiene dimer, carbonyls, inhibitor and residue are measured by appropriate ASTM procedures and the results used to normalize the component distribution obtained by chromatography. This method may be used to check for pentadiene 1,4 and other C5's instead of ASTM Method D1088, Test for Boiling Range of Polymerization Grade Butadiene.