论文部分内容阅读
为测定土壤反硝化培养气体中的N2和O2的浓度,利用厌氧箱制备样品,建立了自动进样器阀进样、填充柱分离,气相色谱-热导检测器测定的方法.N2和O2在2 min内达到基线分离.对于低浓度的样品(N2≤1.0％,O2≤0.254％),使用厌氧箱后N2和O2测定的峰面积比未使用时相比降低约20.0％.目标分析物的保留时间和峰面积的相对标准偏差(RSD)分别小于0.1％和1.0％.N2和O2的线性范围分别为780～60 100 μmol/mol和290～20 000 μmol/mol,线性相关系数均在0.999以上,检出限分别为232.7 μmol/mol和87.5 μmol/mol.厌氧箱的使用很大程度上避免了空气中的N2和O2进入,使培养气体中低含量N2和O2的测定更加准确.“,”An integrated gas chromatographic system has been developed and implemented for measurement of nitrogen and oxygen in the gas of denitrificated soil cultivation.The system employed a practical,effective configuration consisting of the sample preparation in anaerobic tank,auto-injection by valve,separation by packed column and one six-port valve in series with a TCD detector for detection.Separation of two target analytes was achieved in one single analysis within 2 min.The peak area of the sample (N2 ≤ 1.0 ％,O2 ≤ 0.254 ％) was reduced by 20 ％ in anaerobic chamber.The reproducibility of retention times and peak area for N2 and O2 were found to be less than 0.1％ and 1.0 ％,respectively.There were linear ralationships between peak areas and cencentrations in the range of 780-60 100μmol/mol for N2 and 290-20 000μmol/mol for O2,respectively;with detection limits of 232.7 μmol/mol for N2 and 87.5 μmol/mol for O2.The use of anaerobic chamber largely avoided the enterance of nitrogen and oxygen from the air into cultivation gas,making the determination results more accurate.