基于石墨消解法测定海洋沉积物中7种重金属的含量  

Determination of 7 Heavy Metals in Marine Sediments Based on Graphite Digestion Method

作　　者：温婷婷[1,2] 修宝 秦洁 吕则和[1,2] 曾小霖 陈国光[1,2] WEN Tingting;XIU Bao;QIN Jie;LYU Zehe;ZENG Xiaolin;CHEN Guoguang(North China Sea Environmental Monitoring Center,State Oceanic Administration,Qingdao 266033,China;Key Laboratory of Ecological Warning,Protection&Restoration for Bohai Sea,Ministry of Natural Resources,Qingdao 266033,China;Qingdao Huanhai Marine Engineering Survey and Research Institute Co.,Ltd.,Qingdao 266033,China)

机构地区：[1]国家海洋局北海环境监测中心,青岛266033 [2]自然资源部渤海生态预警与保护修复重点实验室,青岛266033 [3]青岛环海海洋工程勘察研究院有限责任公司,青岛266033

出　　处：《理化检验（化学分册）》2024年第4期378-385,共8页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：自然资源部北海局海洋科技项目(2017B02);国家重点研发计划项目(2018YFC1407604);国家海洋局海洋溢油鉴别与损害评估技术重点实验室开放基金(201703)。

摘　　要：鉴于目前常用的海洋沉积物中重金属测定的消解方法存在工作效率低、操作复杂、交叉污染、人员危险性高等问题,通过比对和参考现行规范、标准和文献资料中海洋沉积物重金属的不同消解方法,提出了全自动石墨消解海洋沉积物的方法,并以原子荧光光谱法测定汞和砷的含量,以电感耦合等离子体质谱法测定铜、铅、锌、镉、铬的含量。以6 mL盐酸、2 mL硝酸和8 mL水为消解酸,于100℃消解0.2 g样品1.5 h;消解结束后,冷却至室温,用水定容至50 mL,按照原子荧光光度计的工作条件测定汞和砷的含量。以5 mL盐酸、5mL硝酸为消解酸,先于120℃消解0.2 g样品1 h;然后加入2 mL硝酸、5 mL氢氟酸和2 mL高氯酸,于180℃继续消解4 h;消解结束后,冷却至室温,用水定容至50 mL,按照电感耦合等离子体质谱仪的工作条件测定铜、铅、锌、镉、铬的含量。结果表明:汞、砷标准曲线的线性范围分别在1.00μg·L^(-1)以内和10.0μg·L^(-1)以内,铜、铅、锌、镉、铬标准曲线的线性范围在100μg·L^(-1)以内,汞、砷、铜、铅、锌、镉、铬的检出限(3 s)为0.006~0.522 mg·kg^(-1);使用有证海洋沉积物标准物质进行验证,7种重金属测定值均在认定值的不确定度范围内,相对标准偏差(n=6)为1.4%~7.4%;对3种实际样品进行回收试验,回收率为92.5%~111%。In view of the problems of low work efficiency,complex operation,cross-contamination and high personnel risk in the digestion methods of heavy metals in marine sediments commonly used at present,the fully automatic graphite digestion method was proposed for marine sediments,with atomic fluorescence spectrometry for the determination of mercury and arsenic,and inductively coupled plasma mass spectrometry for the determination of copper,lead,zinc,cadmium and chromium by comparing and referring to different digestion methods of heavy metal in marine sediments in current norms,standards and literatures.The sample(0.2 g)was digested with 6 mL of hydrochloric acid,2 mL of nitric acid and 8 mL of water at 100℃for 1.5 h.After digestion,the solution was cooled to room temperature,and its volume was made up to 50 mL with water,in which mercury and arsenic were determined according to the operating conditions of the atomic fluorescence spectrophotometer.Using 5 mL of hydrochloric acid and 5 mL of nitric acid as the digestion acids,0.2 g of sample was digested firstly at 120℃for 1 h.Then 2 mL of nitric acid,5 mL of hydrofluoric acid and 2 mL of perchloric acid were added,and the sample was digested sequentially at 180℃for 4 h.After digestion,the solution was cooled to room temperature,and its volume was made up to 50 mL with water,in which copper,lead,zinc,cadmium and chromium were determined according to the operating conditions of the inductively coupled plasma mass spectrometer.As shown by the results,the linear ranges of standard curves for mercury and arsenic were within 1.00μg·L^(-1) and 10.0μg·L^(-1),and the linear ranges of standard curves for copper,lead,zinc,cadmium and chromium were within 100μg·L^(-1),with detection limits(3 s)of mercury,arsenic,copper,lead,zinc,cadmium and chromium in the range of 0.006-0.522 mg·kg^(-1).The certified marine sediment reference materials were used for validation,and it was shown that the determined values of 7 heavy metals were all in the uncertainty range of the cert

关 键 词：海洋沉积物 重金属 石墨消解 原子荧光光谱法 电感耦合等离子体质谱法 

分 类 号：O65[理学—分析化学]