溶解有机氮(Dissolved Organic Nitrogen,DON)是天然水体中氮的重要组成部分,目前研究相对很少.本文对淡水中测定DON的两种常见方法即过硫酸钾湿氧化法(Persulfate Oxidation,PO)和高温催化氧化法(High Temperature Cataytic Oxidation,HTCO)进行了对比研究.结果表明:两种方法各有特点,湿氧化法相对较为理想.湿氧化法对不同氮标准化合物的回收率较高,平均为96.0±3.O%以上(杂环氮化合物除外);对湖泊淡水样品,用PO法测定溶解有机氮的相对标准偏差范围为6.2%-12.5%.高温催化氧化法对不同氮标准化合物的回收率较低,平均为68.4±13.6%,需作进一步条件优化.
Dissolved organic nitrogen is an important component of dissolved organic matter in natural aquatic system. But little is known about its characteristics. This study compared two common methods for DON analysis:persulfate oxidation(PO) and high temperature catalytic oxidation(HTCO). The results showed that both methods had their own merits, but better results were obtained using PO method. PO method resulted in higher recovery for various nitrogen-containing standard compounds(96.0 ± 3.0%, excluding heteroyclic nitrogen compounds), and relative standard deviation ranged from 6.2% to 12.5%. The HTCO method yielded relatively low recovery(68.4 ± 13.6% ), and needed further impovement. This study would be helpful for the study of nitrogen biogeochemical cycling in aquatic environment.