1.1 ,The gas chromatography/mass spectrometry (GC/MS) procedure described in this method is used to determine concentrations of total organic halides and total non-methane hydrocarbons (TNMHC) by measurement of individual target halocarbons (Table 1) and hydrocarbons (including formaldehyde, Table 1 and Table 2), respectively. Measurement of these substances is required for application of SAE J2719 to hydrogen fuel quality where this fuel is intended for use in fuel cell vehicles. SAE 2719 states hydrogen fuel is expected to contain less than 0.05 µ,mole/mole total halogenates (including organic halides), 2 µ,mole/mole total non-methane hydrocarbons (C1 Basis, 3.2.16) and 0.01 µ,mole/mole formaldehyde.