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研究了用硅胶整体柱和直接电导检测的离子对色谱快速分析高氯酸盐的方法。实验采用Chromolith Speed ROD RP-18e色谱柱,以氢氧化四丁铵(离子对试剂)+邻苯二甲酸+乙腈(有机改进剂)为淋洗液,讨论了离子对试剂浓度、有机改进剂浓度、pH、色谱柱温度和流速对ClO4-保留时间的影响。确定最佳色谱条件为:0.25mmol/L氢氧化四丁铵+0.18mmol/L邻苯二甲酸+7%乙腈(pH5.5)作为淋洗液,柱温30℃,流速6.0mL/min。在此条件下,ClO4-的保留时间在1min之内。其它常见阴离子(Cl-、NO3-、SO42-和I-)不干扰测定。方法的检出限为1.56mg/L;工作曲线的线性范围是2.4~100mg/L;峰面积的相对标准偏差(RSD,n=5)为1.9%。将本方法应用于测定加标果汁和加标地下水中的ClO4-,加标回收率分别为98.2%和97.6%。
A rapid method for the analysis of perchlorate using ion-pair chromatography with silica gel monolithic columns and direct conductivity detection was studied. The experiment used Chromolith Speed ROD RP-18e column, tetrabutylammonium hydroxide (ion pair reagent) + phthalic acid + acetonitrile (organic modifier) as eluent. The effects of ion pair reagent concentration, organic modifier concentration , PH, column temperature and flow rate on the retention time of ClO4. The optimal chromatographic conditions were as follows: 0.25mmol / L tetrabutylammonium hydroxide + 0.18mmol / L phthalic acid + 7% acetonitrile (pH5.5) as eluent, the column temperature was 30 ℃ and the flow rate was 6.0mL / min. Under these conditions, the retention time of ClO4- is within 1 min. Other common anions (Cl-, NO3-, SO42- and I-) do not interfere with the assay. The detection limit of the method was 1.56 mg / L. The linear range of the working curve was 2.4 ~ 100 mg / L. The relative standard deviation (RSD, n = 5) of the peak area was 1.9%. The method was applied to the determination of ClO4- in spiked fruit juice and spiked groundwater. The spiked recoveries were 98.2% and 97.6% respectively.