反相硅胶整体柱离子色谱法快速分析BrO_3^-

Fast determination of bromate by ion chromatography using a reversed-phase silica-based monolithic column

研究了基于反相硅胶整体柱的离子色谱快速分析BrO3-的方法。以氢氧化四丁铵(TBA)为流动相动态修饰反相硅胶整体柱,采用直接电导检测,在普通高效液相色谱仪上实现了BrO3-和常见阴离子的快速分析。实验考察并讨论了流动相、色谱柱温度和流速对所测阴离子保留和分离的影响。确定分离测定BrO 3-的最佳色谱条件是:以0.75 mmol/L TBA-0.5 mmol/L邻苯二甲酸(pH6.0)为淋洗液,流速3.0 mL/min,柱温30℃。在此条件下,BrO 3-与Cl-、Br-、NO 3-、ClO3-、SO42-、I-7种阴离子在2.2 min内即可分离。BrO 3-的保留时间为36 s,检出限为2.94 mg/L,保留时间和峰面积的相对标准偏差(n=5)分别为0.2%和0.4%。将此方法用于地下水样品的分析,BrO 3-的加标回收率为98.7%。本方法快速、简单和方便。

An ion chromatographic method for the fast determination of bromate has been developed using a reversed-phase silica-based monolithic column dynamically modified with tetrabutylammonium （TBA）. The separation of bromate and common inorganic anions can be achieved on an ordinary high performance liquid chromatographic instrument with direct conductivity detection. The influences of eluent concentration, eluent pH, column temperature and flow rate on the separation and retention of the interested anions were investigated, and the retention mechanisms of the method were discussed. Seven anions （bromate, chloride, bromide, iodide, nitrate, sulfate and chlorate） were separated in just 2. 2 min at a column temperature of 30℃ using an optimized mobile phase. The optimized mobile phase was composed of 0. 75 mmol/L TBA - 0. 5 mmol/L phthalic acid （pH 6. 0） and delivered at a flow-rate of 3 mL/min. The retention time of bromate was 36 s, and the detection limit of bromate was 2. 94 mg/L. The relative standard deviations （n = 5） of retention time and peak area for bromate were 0. 2 % and 0. 4 %, respectively. This method was successfully applied to the determination of bromate in groundwater, and the recovery of spiked bromate was 98. 7 %. This method is fast, simple and easy operation.