Studies of the Gas Density Cell

Abstract

The gas density cell as a gas chromatographic detector possesses the unique possibility of providing both quantitative and molecular weight information. Studies are reported in regard to optimum operational parameters for maximum cell response and upon the accuracy of quantitative and molecular weight measurements. The magnitude of cell response was found to be a function of (1) the value of reference and measuring gas flow rates, (2) the physical properties of the reference gas, and (3) the density change produced in the reference gas by sample vapor. Accuracies of 1–2% for per cent weight and 3–4% for molecular weights were obtained on a large variety of compound types over reasonably wide concentration and molecular weight ranges. An equation was developed which accounts for the variables upon which cell response is dependent and which permits comparison to other type detectors.