1.1 This test 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.