This part of ISO 6974 describes a gas chromatographic method for the quantitative determination of the content of hydrogen, helium, oxygen, nitrogen, carbon dioxide and C1 to C8 hydrocarbons in natural gas samples using three capillary columns. It is applicable to the analysis of gases containing constituents within the mole fraction ranges given in Table 1 and is commonly used for laboratory applications. These ranges do not represent the limits of detection, but the limits within which the stated precision of the method applies. Although one or more components in a sample may not be present at detectable levels, the method can still be applicable.
This part of ISO 6974 is only applicable if used in conjunction with parts 1 and 2 of ISO 6974.
This method can also be applicable to the analysis of natural gas substitutes.
NOTE Additional information on the applicability of this method to the determination of natural gas substitutes is also given where relevant.