A Gas Chromatographic Method for Determination of Nitrous Oxide in Wastewater Treatment

KeyWord:nitrous oxide  gas chromatography  electron capture detector  temperature  carrier gas  sensitivity

Abstract:

      A gas chromatographic£¨GC£© method was established for the analysis of a potential greenhouse gas£¬nitrous oxide£¨N2O£© in wastewater treatment.The optimum conditions of chromatography were determined by a series of parallel tests.The working temperatures of the injector£¬column and electron capture detector£¨ECD£© were 105£¬100 and 300 ¡æ£¬respectively£»95% Ar +5% CH4 was selected as the carrier gas£»the column flow and the makeup gas flow were 25 mL/min and 50 mL/min£¬respectively.Under the optimal conditions£¬the calibration curve was linear in the range of 0.255-100 mg/L N2O£¬with correlation coefficient higher than 0.999 and the mean recovery larger than 90%.When detecting 100 mg/L N2O£¨standard samples£© using direct injection and headspace methods£¬the relative standard deviation£¨RSD£© values were 1.5% and 0.32%£¬respectively£¬and the recoveries were both over 90%.The method was successfully applied in the determination of N2O in wastewater treatment processes and the detected values are consistent with the results reported in literatures.This method is simple£¬sensitive and repeatable.