Yang Shiwei, Zhang Danyu, Cheng Heyong, Wang Yuanchao, Liu Jinhua
College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 311121, China.
College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 311121, China; Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China.
Anal Chim Acta. 2019 Oct 3;1074:54-61. doi: 10.1016/j.aca.2019.04.066. Epub 2019 Apr 29.
For the past several decades, lots of adsorbent nanomaterials have been adopted for the enrichment of mercuric compounds. In this paper, graphene oxide bounded silica particles were employed as the absorbent for online preconcentration of Hg(II), methylmercury (MeHg) and ethylmercury (EtHg) by solid phase extraction. The adsorbent offered satisfactory adsorption capacities of 40.7 for Hg(II), 91.4 for MeHg and 103.8 mg g for EtHg. Enrichment conditions such as type, concentration and volume of conditioning and eluting reagents were optimized. The pH, volume and flow rate of sample were also optimized. High enrichment factors (1963, 1881 and 1794 for Hg(II), MeHg and EtHg, respectively) were obtained with 10 mL sample (adjusted to pH 4-7) at 10 mL min flow rate, 5 μL of 10 mM benzoic acid for elution and 4 mL of 1 mM 4-phenyl-3-aminothiourea for preconditioning. The detection limits obtained were downscaled to be 0.005 for Hg(II), 0.006 for MeHg and 0.009 ng L for EtHg with relative standard deviations of all the analytes below 5%. Standard reference material and spiked water samples were analyzed for validating the method with satisfactory recoveries of 89-106%. The present method was successfully applied to determine mercury compounds in drinking water, and river and tap water, in which Hg(II), MeHg and EtHg were presented below the China's drinking standard limit of 1 μg L.
在过去几十年中，许多吸附性纳米材料已被用于汞化合物的富集。本文采用氧化石墨烯键合硅胶颗粒作为吸附剂，通过固相萃取在线预富集Hg(II)、甲基汞(MeHg)和乙基汞(EtHg)。该吸附剂对Hg(II)、MeHg和EtHg的吸附容量分别为40.7、91.4和103.8 mg g，令人满意。优化了调节和洗脱试剂的类型、浓度和体积等富集条件。还对样品的pH值、体积和流速进行了优化。在流速为10 mL min、进样量为10 mL（调节至pH 4 - 7）、用5 μL 10 mM苯甲酸洗脱和4 mL 1 mM 4 - 苯基 - 3 - 氨基硫脲预处理的条件下，Hg(II)、MeHg和EtHg的富集因子分别高达1963、1881和1794。所获得的检测限分别为Hg(II) 0.005、MeHg 0.006和EtHg 0.009 ng L，所有分析物的相对标准偏差均低于5%。分析了标准参考物质和加标水样以验证该方法，回收率为89 - 106%，令人满意。该方法成功应用于测定饮用水、河水和自来水中的汞化合物，其中Hg(II)、MeHg和EtHg的含量均低于中国饮用水标准限值1 μg L。
