The MA VPH standard consists of 14 components they are (C5) n-pentane 1000 μg/ml, (C9) n-nonane 1000 μg/ml, benzene 500 μg/ml, 2,5-dibromotoluene (SS) 1000 μg/ml, ethylbenzene 500 μg/ml, 2-methylpentane 1500 μg/ml, methyl tert-butyl ether (MTBE) 1500 μg/ml, naphthalene 1000 μg/ml, toluene 1500 μg/ml, 1,2,4-trimethylbenzene 1000 μg/ml, 2,2,4-trimethylpentane (isooctane) 1500 μg/ml, m-xylene 1,000 μg/ml, o-xylene 1,000 μg/ml and p-xylene 1,000 μg/ml.