GAS CHROMATOGRAPHY
HIGH-PURITY ANALYSIS FOR A RANGE OF GASES
Gas Chromatography ( GC ) separates out a mixture in the gas phase to determine the presence and concentration of constituent components . Under optimized conditions , it can measure down to parts-perbillion ( ppb ) levels , making it ideal for high purity processes .
The components of a mixture in the gas phase are separated by introducing a small portion of the sample into a flowing carrier gas ( mobile phase ), which percolates through a stationary phase consisting of particulates packed within a column .
The different gas constituents are separated due to their own specific , adsorptive interaction between the stationary phase and the mobile phase . This causes the constituents to exit the column ( elute ) at different times .
These specific times are detected at the exit of the column . By comparing times , users can identify analytes by the order in which they elute from the column . Each constituent concentration is determined , after calibration , from the integral of each analyte ’ s detector response time .
The conditions under which GC technology operates differ for each application , and require individual optimization .
THE GAS CHROMATOGRAPHY TECHNIQUE
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