PROCESS OF QUANTITATIVE GAS CHROMATIC DETECTION OF WATER IN GAS MIXTURES Russian patent published in 2003 - IPC

FIELD: analytical chemistry, gas chromatic analysis of water. SUBSTANCE: measurement system is dried before dosing of examined gas mixture, analyzed sample is concentrated by alternation of inert gas blowing through system with heating and evacuation with test of degree of drying by background peak of water in test chromatogram of atmosphere in measurement system till mentioned peak is removed. Concentration of sample is carried out from closed vessel by sorption of sample with cooling to temperature of liquid nitrogen with subsequent desorption with heating to temperature above water boiling point. Desorption is performed in device of the type of trap coming in the form of U-shaped tube submerged first into cooling medium and then into heating one. Content of water is detected by direct gas chromatographic method with measurement of analytical signal of heat conduction detector on basis of conducted calibration measurements with preparation of calibration samples. Calibration measurements are carried out with the help of calibration samples of air, each sample being characterized by pressure growing consistently, and with construction of calibration graphs of dependence of height of water peak in each due calibration sample of air on water content in reference sample of air established by psychrometer. Tested gas mixture is goes into measurement system by passage through metal tube placed between examined vessel and trap, fitted with heater. Gas chromatographic determination of content of water is realized with the help of column filled with polychrom-1 in the capacity of solid carrier treated with liquid phase. EFFECT: possibility of examination of closed vessels under pressure below atmospheric, shortened time of analysis, exception of labor-intensive stage of preparation of liquid calibration samples of fixed composition, enhanced reliability of process thanks to reduction to homogeneous phase state of both analyzed and calibration samples. 1 dwg