饮用水中高氯酸盐的离子色谱碳酸盐体系测定法

Determination of perchlorate in drinking water by ion chromatography carbonate system

目的建立饮用水中高氯酸盐的离子色谱(IC)碳酸盐体系测定方法。方法水样经0.22μm针式过滤器过滤,当水样中硫酸盐浓度小于300 mg/L时,可直接进样;硫酸盐浓度大于300 mg/L时,可使用lC-Ba离子色谱前处理柱降低硫酸盐浓度后再进样,进样体积为250μl。选用Metrosep A supp 4(250 mm×4.0 mm)色谱柱及Metrosep A supp 5 Guard(5 mm×4.0 mm)保护柱进行色谱分离,以4.0 mmol/L碳酸钠-1.7 mmol/L碳酸氢钠溶液作为淋洗液,等度淋洗,采用电导检测器进行定性和定量分析。结果在5~140μg/L的线性范围内,所得高氯酸盐的回归方程为y=0.000619x-0.000522,r=0.9996。该方法的检出限为2μg/L,定量下限为5μg/L;加标回收率为94.0%~104.0%,RSD为0.18%~3.86%。结论该方法样品预处理简便、耗时短,仪器普及率高,操作简单、快速,经济成本较低,准确度和精密度均较高,可用于检测饮用水中的高氯酸盐。

Objective To establish a method for the determination of perchlorate in drinking water by ion chromatography carbonate system.Methods The water samples were filtered by 0.22μm needle filter.The direct injection was conducted for the the water samples containing≤300 mg/L sulfate,IC-Ba ion chromatography pretreatment column was used to reduce the sulfate concentration before sample injection for the water samples containing>300 mg/L sulfate,the injective volume was 250μl.Metrosep A supp 4(250 mm×4.0 mm)analytical column and Metrosep A supp 5 Guard(5 mm×4.0 mm)guard column were employed with 4.0 mmol/L sodium carbonate-1.7 mmol/L sodium bicarbonate solution as the eluent for equivalent elution,the conductivity detector was used for qualitative and quantitative analysis.Results In the linear range of 5-140μg/L,the regression equations of the perchlorate showed good liner relationship,the correlation coefficient was 0.9996.The limits of detection was 2μg/L,the limit of quantification was 5μg/L.The recovery rates were 94.0%-104.0%,and the RSDs were 0.18%-3.86%.Conclusion This method has the advantages of simple sample pretreatment,time saving,high penetration of instrument,simple and rapid operation,low cost,high accuracy and precision,and is applicable to the determination of perchlorate in drinking water.