高效液相色谱-荧光检测法测定饮用水中的亚硝酸盐

Rapid determination of nitrite in drinking water by high performance liquid chromatography with fluorescence detection

目的建立一个简单、准确、灵敏的高效液相色谱-荧光检测法,测定饮用水中的亚硝酸盐。方法亚硝酸盐在酸性条件下和2,3-萘二铵反应生成有强荧光物质2,3-萘三唑(NAT),反应产物经色谱柱Eclipse XDB-C8(5μm,4.6 mm×150 mm)分离,流动相为水和乙腈(体积比70∶30),流速为1.0 ml/min。采用荧光检测器进行检测,激发波长为375 nm,发射波长为415 nm。同时研究了水样中亚硝酸盐衍生产物NAT的稳定性。结果亚硝酸盐浓度在0μg/L~100μg/L中具有良好的线性,相关系数为0.9998,检出限和定量限分别为0.3μg/L和1.0μg/L,回收率在90.3%~102.6%,相对标准偏差为0.70%~3.67%。NAT含量水平在一个星期之内的相对误差不大于13.4%。结论方法操作简便、准确度好、精密度高,衍生产物稳定性好,可以用于饮用水中亚硝酸盐的测定。

Objective This study is to establish a simple,accurate and sensitive method for the determination of nitrite in drinking water by high performance liquid chromatography with fluorescence detection.Methods Nitrite in the water reacted with 2,3-diaminonaphthalene in acidic conditions to form a strong fluorescent substance of 2,3-naphthotriazole(NAT),which was analyzed by the high performance liquid chromatography with fluorescence detection.The analysis column was Eclipse XDB-C8(5μm,4.6 mm×150 mm)column.A constant flow rate of 1.0 ml/min was employed using water-acetonitrile as mobile phase in isocratic mode(70:30,V/V).Fluorescence was monitored with excitation at 375 nm and emission at 415 nm.The stability of NAT which was the derivative of nitrite in water samples was also studied.Results The standard calibration curve was linear for nitrite in the concentration range of 0μg/L-100μg/L,and the correlation coefficient was 0.9998.The limit of detection was 0.3μg/L and the limit of quantification was 1.0μg/L.The recoveries of nitrite from samples spiked at three different concentrations were within 90.3%-102.6%,and the relative standard deviation of recovery results were 0.70%-3.67%.The relative error of NAT in water samples within one week was not more than 13.4%.Conclusion The proposed method is simple,accurate and sensitive with the good stability of derivative.It could be used for the determination of nitrite in drinking water.