超声提取-离子色谱法测定常见土壤中的高氯酸盐

Determination of Perchlorate in Common Soil by Ion Chromatography with Ultrasonic Extraction

建立了测定土壤中高氯酸盐的离子色谱法,通过前处理条件优化和色谱条件优化形成准确高效的测定方法,并采集实际土壤样品进行实验验证。称取1.00 g土壤样品,用20 mL超纯水混合均匀,超声提取40 min,离心后采用水系微孔滤膜过滤的前处理方式,土壤中高氯酸盐的加标回收率最稳定;在淋洗液浓度和流速都满足测定条件的前提下,为了缩短高氯酸盐的保留时间,避免复杂基质干扰,延长淋洗液发生器的使用寿命以及保护色谱柱,选择淋洗液浓度为40 mmol/L,流速为1.0 mL/min。在优化条件下,高氯酸盐的方法检出限为0.04 mg/kg。实际样品加标中高氯酸盐的相对标准偏差为1.9%~8.8%,加标回收率为91.0%~106%,结果表明离子色谱法测定土壤中高氯酸盐简单、灵敏、快速。

A method was established for the determination of perchlorate in soil using ion chromatography.The optimal determination method was obtained by optimizing pretreatment and chromatographic conditions,which was verified using actual soil samples collected.When 1.00 g soil sample was weighted and mixed evenly with 20 mL of ultra-pure water,ultrasonically extracted for 40 min and centrifuged,than pretreated with stream microporous filter membrane,the recovery of perchlorate in soil was the most stable.In order to shorten the retention time of perchlorate,avoid complex matrix interference,prolong the service life of the eluent generator and protect the chromatographic column,the optimal eluent concentration was 40 mmol/L,and the flow rate was 1.0 mL/min on the premise that all conditions met the determination requirements.Under the optimized conditions,the limit of detection for perchlorate was 0.04 mg/kg.The relative standard deviation of perchlorate in soil samples ranged from 1.9%to 8.8%,and the recoveries were within the ranges of 91.0%-106%.The results showed that the method of ion chromatography for the determination of perchlorate in soil was simple,sensitive and rapid.