基于改性淋洗液离子色谱法测定水中高氯酸盐

Determination of perchlorate in water by ion chromatography based on modified leaching solution

目的建立高氯酸盐与常见阴离子有效分离的简便快速分析方法。方法选用Metrosep A Supp 4(250/4.0)色谱柱,在4.0 mmol/L Na2CO3+1.7 mmol/L NaHCO3的常规流动相中加入5%乙腈,能成功分离样品中的干扰物质。结果高氯酸盐浓度在7.0~200μg/L范围内具有良好的线性,相关系数为0.9999,检出限为2μg/L,回收率在94.0%~101%之间,常见阴离子及某些疏水性物质与高氯酸盐有效分离。在483份水样中,高氯酸盐的检出率为95.2%,最大值为0.60 mg/L,均值为0.078 mg/L,P50为0.047 mg/L。结论该方法简单、灵敏、快速,检出限低,采用有机改性剂,既可去除水中疏水性物质的干扰,又可缩短分析时间和改善峰形,适用于水中高氯酸盐的检测。

Objective To establish a simple and rapid method for effective separation of perchlorate from common anions.Methods The analysis was conducted using Metrosep A Supp 4(250/4.0)columns.By incorporating 5%acetonitrile into the standard eluent consisting of 4.0 mmol/L sodium carbonate and 1.7 mmol/L sodium bicarbonate,the interference from the samples was effectively eliminated.Results There was a good linear relationship of perchlorate in the mass concentration range of 7.0-200μg/L,with a correlation coefficient of 0.9999.The method detection limit was determined to be 2μg/L.The recovery rates ranged from 94.0%to 101%.Perchlorate was effectively separated from common anions and hydrophobic substance.The detection rate of perchlorate in 483 water samples was 95.2%,with the maximum value being 0.60 mg/L,the average value being 0.078 mg/L and P50 being 0.047 mg/L.Conclusion The established method is simple,sensitive and rapid,and has a low detection limit.Using organic modifier not only eliminates the interference caused by hydrophobic substance in water but also reduces the analysis time and enhances the peak shape.The method is suitable for the determination of perchlorate level in water.