Research Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou, Zhejiang, P. R. China.
J Sep Sci. 2013 Nov;36(21-22):3579-85. doi: 10.1002/jssc.201300770. Epub 2013 Oct 1.
An ultrasound-assisted magnetic SPE procedure with an Fe3 O4 -grafted graphene nanocomposite as the magnetic adsorbent has been developed to determine seven polychlorinated biphenyls (PCBs; PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) simultaneously in 200 mL environmental water samples, in combination with GC-MS/MS. Several factors related to magnetic SPE efficiencies, such as the superparamagnetic intensity and amount of adsorbent, extraction time, sample pH, and desorption conditions were investigated. With the assistance of ultrasound, the extraction achieved the maximum within only 20 s, attributed to the powerful adsorptive ability of the magnetic adsorbent toward the PCBs. Under the optimized conditions, an excellent linearity was observed in the range of 0.1-100 ng/L for PCB28, 0.2-100 ng/L for PCB52, and 0.5-100 ng/L for the other five PCBs with the correlation coefficients ranging from 0.9988 to 0.9996. The mean recoveries at spiked levels of 5.0 and 10.0 ng/L were 84.9-108.5%, the coefficients of variations were <6.5%. With convenient magnetic separation, the synthesized magnetic adsorbent could be recycled more than ten times. The proposed method was demonstrated to be feasible, simple, rapid, and easy to operate for the trace analysis of the PCBs in environmental water samples.
一种基于超声辅助的磁固相萃取方法，采用 Fe3 O4 接枝石墨烯纳米复合材料作为磁性吸附剂，结合 GC-MS/MS 同时测定 200 mL 环境水样中的七种多氯联苯（PCBs；PCB28、PCB52、PCB101、PCB118、PCB138、PCB153 和 PCB180）。研究了与磁固相萃取效率相关的多个因素，如超顺磁性强度和吸附剂用量、萃取时间、样品 pH 值和洗脱条件。在超声辅助下，仅需 20 s 即可达到最大萃取效果，这归因于磁性吸附剂对 PCBs 具有强大的吸附能力。在优化条件下，PCB28 的线性范围为 0.1-100 ng/L，PCB52 的线性范围为 0.2-100 ng/L，其他五种 PCBs 的线性范围为 0.5-100 ng/L，相关系数范围为 0.9988-0.9996。在 5.0 和 10.0 ng/L 两个加标水平下的平均回收率为 84.9-108.5%，变异系数均小于 6.5%。由于方便的磁分离，合成的磁性吸附剂可以重复使用十多次。该方法具有可行性、简单、快速和易于操作的特点，可用于环境水样中痕量 PCBs 的分析。
