一种直接测定硝化—反硝化气体的15N示踪—质谱法
A METHOD FOR DIRECT MEASUREMENT OF 15N-GASES FROM NITRIFICATION-DENITRIFICATION WITH MASS SPECTROMETER
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摘要: 本文对15N示踪质谱法的可靠性进行了检验。结果表明,在不同的15N丰度气体样品的测定中,用两种方法(反硝化作用源的15N丰度法和气样的15N丰度法)计得的反硝化损失量基本一致,故建立起来的15N示踪质谱法是可靠的。该方法的测定偏差随气样15N丰度的降低而增大。此外,回收率结果表明,(N2+N2O+NOx)-15N累积释放量占加入NO3-15N量的94.1％。因此,这一方法可用于直接测定氮肥的硝化反硝化损失的研究中。Abstract: Reliability of the method developed in the laboratory for direct measurement of (N2+N2O+NOx)-15N from nitrification-denitrification was examined in the present paper. The results showed that the amount of (N22+N2O+NOx)-15N produced thuough denitrification of added 15N-nitrate by the two methods (15N enrichment of the NO3-N pool undergoing denitrification, and 15N enrichment of the gas samples) were measured accurately; the recovery of added 15N-nitrate as (N2+N2O+NOx)-15N from denitrification was up to 94. 1% in the flooded incubation experiment. The error of the method was increased with decrease in 15N enrichment of gas samples. It is concluded that the method is reliably. Therefore, investigation on nitrification-denitrification loss of fertilizer nitrogen can be done by using the method.
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