Gas analysis using mine site gas chromatographs has traditionally been restricted generally to permanent gases (i.e. helium, hydrogen, oxygen, nitrogen, methane, carbon monoxide, carbon dioxide, ethylene and ethane). Improvements in the technology now allow for additional gases such as aliphatic hydrocarbons and BTEX to be analysed. Aliphatic hydrocarbons and BTEX have implications for the detection of spontaneous combustion, currently under investigation by ACARP project C25072. This paper will detail the modifications needed to enable analysis of these gases existing mine site equipment. The analysis capabilities of the modified equipment will be determined and examples of the chromatography produced by the system provided. The stability of the samples will be analysed in terms of the existing sampling procedures and equipment utilised. The stability of the samples with regard to any recommended new sampling procedures and equipment will also be outlined.