1. (based on a 95% confidence level using a coverage factor (k) of 2) of seven indicator PCBs changed from 3.50 to 4.38. The contribution from sample preparation, calibration curve, and repeatability were the major sources of the expanded uncertainty. In real case studies, 9.24% of sewage sludges, 16.66% of soils and 34.18% of waste oil samples yielded results above the LOQ for at least one indicator PCB. In addition, at least three indicator PCBs were detected in these twenty-seven waste oil samples. The most common ones are PCB 28, PCB 101, and PCB 153. Thus, this optimized method presents a magnifical ability for application in routine analysis for the determination of PCBs present in complex solid and waste oil samples;the measurement uncertainty
2. United Nations Environmental Programme, Guidelines for the identification of PCBs and materials containing PCBs;United Nations Environment Program,1999
3. Determination of indicator polychlorinated biphenyls (PCBs) by gas chromatography-electron capture detector;S Afful;Chemosphere,2013
4. Analytical chemistry of the persistent organic pollutants identified in the Stockholm Convention: A review;W Xu;Anal. Chim. Acta,2013
5. Polychlorinated biphenyls (PCBs) in the environment: Recent updates on sampling, pretreatment, cleanup technologies and their analysis;A V B Reddy;Chem. Eng. J,2019