天然水中No_2^-和NO_3^-的毛细管电泳分离测定

Determination of Nitrite and Nitrate in Water by Capillary Electrophoresis.

在pH8.2硼酸缓冲液中,用高效毛细管电泳分离亚硝酸根,硝酸根,并用内标法直接检测了矿泉水,井水中的NO_2^-、NO_3^-.以CTAB为电渗流改性剂,离子迁移时间相对标准偏差小于1.5%;二甲亚砜作为内标,样品对内标的峰高比重现性较好.检测下限NO_2^-为2.5×10^(-11) mol/L,NO_3^-为1.8×10^(-11)Mol/L,分析结果与离子色谱对照,符合较好。

Nitrite and nitrate in mineral water and well water have been determined by capillary electrophoresis with internal standard method at 211 nm in pH8. 2 borate buffer. Cetyltrimethylammonium bromide (CTAB) was used as electroosmotic flow modified (EOF) reagent, and the reproductivity RSDs of migration time for nitrite and nitrate anions were less than 1.5%. Dimethyl sulfoxide(0.05%) was applied as the internal standard in this detection, and the RSDs of peak high ratio of anions to dimethyl sulfoxide were around 20% for the concentration at μg/g level. Detection limits for nitrite were 2.5×10^(-11) mol, and 1.8×10^(-11) mol, respectively. The results were good agree with the results of ion chromatography.