红树林沉积物中痕量多氯联苯的分析方法

 多氯联苯（PCBs）对红树林生态系统存在着一定的生态风险，对红树林沉积物中PCBs的监测有重要意义。报道了一种适用于红树 林沉积物样品痕量PCBs的分析方法，并对其质量保证与质量控制（QA/QC）进行了研究。分别采用超声萃取（USE）和微波辅助萃 取（MAE）对沉积物样品进行提取，针对样品的特点，联合运用铜片超声、酸洗和中性氧化铝—改性硅胶复合层析柱对PCBs纯化 分离，以气相色谱—质谱联用仪（GC/MS）和外标法进行定量。实验结果表明，两种萃取方法与GC/MS联用均有较高的回收率，超 声萃取的回收率为47.45%~100.76%，微波辅助萃取的回收率为77.04%~98.00%，但微波辅助萃取的精确度更高；方法检测限 前者为0.30~1.74 ng/g，后者为0.30~0.47 ng/g。故选用微波辅助萃取—GC/MS联用的分析方法更优。

Determination of Trace PCBs in Mangrove Sediments

As polychlorinated biphenyls (PCBs) in mangrove ecosystem may cause ecological risk, monitoring of PCBs in sediments is of great importance. This work presents the determination of trace PCBs in mangrove sediment samples, under the condition of quality assurance/quality control(QA/QC). In this study, both ultrasonic extraction(USE) and microwave assisted extraction(MAE) are tried.According to properties of the samples, PCBs are cleaned up with copper, sulfuric acid and alumina-silica chromatography column. Then,PCBs are detected by the apparatus of GC/MS. The results show that both USE and MAE have high recoveries. The recoveries of the whole analysis range from 47.45% to 100.76% by USE and from 77.04% to 98.00% by MAE, respectively,and MAE has higher accuracy The method detection limits for PCBs range from 0.30 to 1.74 ng/g by USE and from 0.30 to 0.47 ng/g by MAE. So MAE is a better choice.