METHODS DETERMINATION OF NITROUS OXIDE EMISSIONS IN RICE FIELD BY GAS CHROMATOGRAPHY (GC)

Abstract

ABSTRACT

This study was undertaken to develop and validate an accurate, sensitive and reproducible Gas chromatographic (GC) method for the quantitation of nitrous oxide emission in rice field. The sample and the standard  were eluted from Porapak Q (4m×2mm ID glass, 80/100 mesh), Hayesep (4m×2mm ID glass, 80/100 mesh) (Supelco, Sigma – Aldrich Co, Singapore). Using nitrogen as carrier gas at a flow rate of 40kPa. Each analysis required no longer than 11 min. The limit of quantitation was 0.03 ppmV. Recovery for different concentrations ranged from 98% to 100%. The calibration curves were obtained in the concentration range 0.125–1.5 ppmV. The results showed a close correlation coefficient (R2 = 0.9998) for analyte in the calibration range studied. The reproducibility RSDs ranged from 4.02%. The simplicity of this low-cost, rapid technique and its high specificity to nitrous oxide, even in the presence of other gas, demonstrate this GC method would be particularly suitable for the determination of nitrous oxide emissions in rice fields of VietNam.