二极管阵列检测离子色谱法测定水中NO_2^-、Br^-、NO_3^-

Determination of nitrite,bromide and nitrate in water by anion-exchange chromatography with photodiote array detection

目的:建立直接紫外检测离子色谱法测定水中NO2-、Br-、NO3-的方法,并用于水中NO2-、Br-、NO3-的检测。方法:采用IonPac AS14-2mm型阴离子分离柱,以3.5 mmol/L Na2CO3+1.0 mmol/L NaHCO3为淋洗液,二极管阵列检测法,NO2-、Br-、NO3-的检测波长分别为210、199、205 nm。结果:直接紫外检测法不受多种共存离子的干扰,可选择每一种组分的最佳吸收波长进行分析。于分离柱与检测池之间添加抑制器可降低背景吸收,消除氯离子和硫酸根离子的负峰。各阴离子的线性好(r>0.9990),相对标准偏差均小于5%(n=7),平均加标回收率均在97.7%~101.5%之间,NO-、Br-、NO-的检出限分别为0.20、0.26、0.21μg/L。结论:本文所用方法灵敏、快速,适用于所有的饮用水分析。

Objective： To develop an ion - chromatography method for determination of nitrite, bromide and nitrate in water using ion chromatography in water by photodiote array detection. Methods：Nitrite, bromide and nitrate is separated on the IonPac AS14- 2mm column using a 3.2 mmol/L Na2CO3/1.0 mmol/L NaHCO3 solution, and detected using ion chromatography with photodiote array detection. The maximum absorbance wavelength for each peak deteete at 210,199,205 nm. Results：The method is free from most ionic interferences due to the specificity of UV detection. Wavelengths can be selected to analyze each compound at its highest sensitivity. The use of a suppressor between the column and the detector cell reduces background absorbance and eliminates negative peaks associated with chloride and sulfate in this method. The peak area response was found to be linear for nitrite, bromide, and nitrate. Linearity is good （r 〉 0. 9990）. Analyte recoveries ranged from 97.7% - 101.5%. The method detection limit was 0. 20,0. 26,0. 21 μg/L. Conclusion： This method is specific, sensitive, and rapid. This method is applicable to all drinking water samples.