聚焦耦合微波萃取沉积物中甲基汞前处理条件的研究

Study on Pretreatment Condition of Extracting of Methylmercury in Sediments by Focusing Coupling Microwave-assisted

甲基汞是毒性最大的汞化合形态,并且是沉积物中汞的重要存在形式,研究沉积物中甲基汞的分离富集及检测技术具有重大意义。本文采用正交实验法,考察了用聚焦耦合微波萃取沉积物中甲基汞时,二氯甲烷用量、盐酸用量、萃取温度、萃取时间等四种因子对预处理效果的影响程度,并对各个影响因子进行了优选。本法对甲基汞的检出限为0.67μg.kg-1;在0.2μg.L-1～12.8μg.L-1范围内,线性相关程度良好,相关系数为0.999;回收率在85.4%～105.13%之间;相对标准偏差(RSD)≤5%(n=7),满足沉积物中超痕量甲基汞的分析要求。

Methymercury is the most toxic state among mercuryspeciation, also the important occurrence in sediments. Therefore, it is meaningful to study the separation, enrichment and check technology of methymercury in sediments. The orthogonal test was carried out to investigate the influence of the dosage of dichloromethane and hydrochloric acid and the extracting temperature and time on the pretreatment. Meanwhile, the selectivity of different factors was carried out. The detection limit is 0.61 μg/mL. From the extent of 0.2μg . L^-1- 12.8 μg. L^-1 , the linear correlation degree is relatively good, whose correlation coefficient is 0.999. The recovery is from 85.4% to 105.13 % and the relative standard deviation is not more than 5 % （ n = 7 ）, which meets the requirement that analyze the ultratrace methymercury in sediment.