环境水体中亚硝态氮、硝态氮和总氮的液相色谱测定

Determination of Nitrite,Nitrate and Total Nitrogen in Environmental Water by HPLC

建立了环境水体中NO2^-、NO3^-及总氮含量的液相色谱测定方法。采用Hypersil ODS（5μm，250mm×4．6mm i．d．）色谱柱；流动相：17．5mmol／LKH2PO4—2mmol／LH3PO4缓冲液（pH3．5）-乙腈（体积比92．5：7．5）；流速：0．8mL／min；柱温：30℃；紫外检测器：波长204nm。结果表明：水体中NO2^-和NO3^-的线性范围（以N计）：1—80ng，r=0．9999；方法检出限：NO2^-0．4ng、NO3^- 0．09ng;回收率为NO2^- 99．2％～102．4％、NO3^- 98．7％-99．3％，RSD为0．79％和0．25％。

A new high-performance liquid chromatography（HPLC） method was established to determine the contents of total nitrogen, nitrite and nitrate in environmental water. A Hypersil ODS （5 μm, 125 mm ×4. 6 mm） column was selected as the chromatographic column, with mobile phase of V（A） ： V（B） =7. 5 ： 92. 5（A： acetonitrile, B： 2 mmol/L H3PO4 - 17. 5 mmol/L KH2PO4, pH 3.5） at a flow rate of 0. 8 mL/min, UV detection wavelength of 204 nm, and oven temperature of 30 ℃. The results showed that the determination linearities of nitrate and nitrite in water were 1 - 80 ng （by nitrogen）, and the correlation coefficient between concentrations and peak areas for nitrate and nitrite were 0. 999 9. The detection limits for nitrite and nitrate were 0. 4 ng and 0.09 ng, the recoveries were 99.2%- 102.4% for nitrite and 98. 7% - 99. 3% for nitrate, and the RSD for nitrite and nitrate were 0.79% and 0. 25% , respectively.