在线富集纯化法测定海水中10种微量元素

Application of Online Enrichment and Purification Device to Detecting 10 Trace Elements in Seawater

【目的】建立一种通过除盐装置在线富集纯化而测定海水中重金属元素的方法,以解决由海水中高盐基质导致的部分微量元素定量检测困难的问题。【方法】通过以高分子有机聚合物聚苯乙烯-二乙烯基苯(PS-DVB)为基质的螯合柱吸附对高盐基体中的Mn、Fe、Co、Ni、Cu、Zn、Cd、Pb、V、U等10种微量元素进行富集,并用电感耦合等离子体质谱法(ICP-MS)测定微量元素含量,评估该方法的精密度、准确度,并探究样品pH对检测的影响。使用该方法检测西太平洋表层海水样品和厦门近岸海水样品中微量元素,评估该方法的实际样品适用性。【结果】分析流程空白中各元素质量浓度在0.001~0.208μg/L之间,检测限在0.002~0.211μg/L之间,标准曲线相关系数r^(2)均大于0.999。海水标准物质(GBW-080040)和河口微咸水标准物质(SLEW-3)的pH为2~6时,测试结果准确度较佳,而碱性样品则不适合直接上机测试。SLEW-3各元素精密度为0.75%~5.98%,GBW-080040各元素精密度为0.10%~0.94%。SLEW-3检测值与理论值的相对误差为-7.46%~11.11%,加标回收率为96.83%~105.17%;而GBW-080040检测值与理论值相对误差为-3.98%~3.72%,加标回收率为93.04%~101.10%。远洋表层海水样品各元素加标回收率为93.25%~111.62%,厦门近岸海水各元素加标回收率为95.89%~107.18%。【结论】该方法适合实时在线同步分析高盐基质样品中Mn、Fe、Co、Ni、Cu、Zn、Cd、Pb、V、U等10种微量元素的含量,方法的稳定性、精密度、准确度较高,可应用于实际海水样品的检测,为复杂基质样品中低含量元素的快速检测提供技术支持。

【Objective】The aim of this paper is to establish a method for online enrichment and purification of heavy metal elements in seawater,to overcome the difficulty of quantitative detection of some trace elements in seawater because of high salt matrix in seawater.【Method】Enrichment of 10 trace elements,namely Mn,Fe,Co,Ni,Cu,Zn,Cd,Pb,V,and U,in a high salt matrix was achieved through adsorption using a chelating column based on polystyrene divinylbenzene(PS-DVB),one high molecular weight organic polymer.The trace element contents were detected by inductively coupled plasma mass spectrometry(ICP-MS),and the precision and accuracy of the method were evaluated.The influence of sample pH on detection was also explored.This method was used to detect trace elements in surface seawater samples from the Western Pacific and nearshore seawater samples from Xiamen,and the practical sample applicability of this method was evaluated.【Result】In the analysis process blank,each element was between 0.001‒0.208μg/L,the detection limit was between 0.002‒0.211μg/L,and the correlation coefficient r^(2) of each standard curve was greater than 0.999.The pH gradient experiments were conducted on seawater standard substance GBW-080040 and estuarine brackish water standard substance SLEW-3.When the sample pH was between 2‒6,the accuracy of the test results was good,but alkaline samples were not suitable for direct testing.The precision of each element was evaluated through parallel experiments,and the standard substance SLEW-3 for estuarine brackish water ranged from 0.75%to 5.98%,while the standard substance GBW-080040 for seawater ranged from 0.10%to 0.94%.The relative error of SLEW-3 ranged from‒7.46%to 11.11%,and the spiked recovery rate ranged from 96.83%to 105.17%,while the relative error of GBW-080040 ranged from,‒3.98%to 3.72%,and the spiked recovery rate ranged from 93.04%to 101.10%.The spiked recovery rate of each element was found to be between 93.25%‒111.62%for deep-sea surface seawater samples and 95.89%‒107.18%for nearshore seawater samples in Xiamen.【Conclusion】This method is suitable for real-time online synchronous analysis of the 10 trace elements,i.e.Mn,Fe,Co,Ni,Cu,Zn,Cd,Pb,V and U,in high salt matrix samples.The stability,precision,and accuracy of the method are good,and it can be applied to the detection of actual seawater samples,providing technical support for the rapid detection of low content elements in complex matrix samples.