中文摘要：

细菌反硝化法是目前同时分析天然水中硝酸盐氮、氧同位素组成的最新方法。该方法包括反硝化菌的选取与培养，利用反硝化菌将硝酸根完全转化成N2O气体以及N2O气体的提取、纯化和同位素测定。该方法采用硝酸盐标准，对测试结果需进行试剂本底、同位素分馏、同位素交换校正。与传统方法相比，细菌反硝化法可同时分析低浓度微量水中硝酸盐的氮、氧同位素组成，且速度更快捷，结果更可靠。

英文摘要：

The nitrogen and oxygen isotopic analysis of nitrate in water with bacterial denitrification at one time is a new method. It contains denitrifier strains selecting and culturing, complete conversion of sample nitrate to nitrous oxide by denitrifying bacteria, nitrous oxide extracting and purging, isotopic analysis of nitrous oxide. This method adopts nitrate standard, and its corrections contain isotopic fractionation, exchange and blank. Compared with combustion method, bacterial denitrification method can analyse nitrogen and oxygen isotopic composition of nitrate in minim water sample with lower concentration at one time, and is more convenient and reliable.