GC for Analysis of Natural Gas

In this method, components in a representative sample are physically separated by gas chromatography (GC) and compared to calibration data obtained under identical operating conditions from a reference standard mixture of known composition. Numerous heavy-end components of a sample can be grouped into irregular peaks by reversing the direction of the carrier gas through the column at specific times, grouping the heavy ends as C5 and heavier, C6 and heavier, or C7 and heavier. The composition of the sample is calculated by comparing the peak heights, peak areas, or both with the corresponding values obtained from the reference standard.