Intended to enable trained scientists to equip themselves to successfully perform analyses of complex gas mixtures. The equipment and the considerations governing the choice of carrier gas are described in detail. Selection of methods for use on complex mixtures often involves the choice of more than one column; the separating capabilities of column packing and how they can be used in combinations are described and numerous examples are given. The handling of samples prior to separation and the calculation of results after separation, including calibration, are described. Throughout, special emphasis is given to the differences between gas analysis and the better documented liquid analysis.