TECHNIQUE OF GAS-CHROMATOGRAPHIC DETERMINATION OF NITROGEN LOWER OXIDE IN GASES Russian patent published in 2004 - IPC

FIELD: analytical chemistry. SUBSTANCE: invention refers to gas-chromatographic determination of nitrogen lower oxide utilized in chemical industry for analytical test of production of mineral fertilizers. In compliance with technique analyzed mixture is separated in flow of carrier gas in chromatographic column which uses zeolite CaX with water content between 13-17 per cent by mass in the capacity of sorbent which is produced by thermal treatment of starting zeolite CaX according to technical specifications TY 38-110281-80 under vacuum at temperature of 100 C in the course of 1.5 h with subsequent cooling with bleeding-in of helium into closed flask where thermal treatment was conducted and its further modification with polyethylene glycol 1000 taken in the amount of 0.5-1.0% of zeolite mass. This approach results in selectivity, efficiency and high sensitivity of determination of nitrogen lower oxide- 2.0 mg/cu m (0.5 maximum permissible concentration). Technique can be realized under automatic mode in chromatographs manufactured on mass scale. EFFECT: high selectivity, efficiency and sensitivity of determination of nitrogen lower oxide in gases. 6 cl, 1 dwg, 5 tbl