Journal of Chromatography & Separation Techniques
Open Access

Abstract

Development and Validation of a Gas Chromatography-Mass Spectrometry Method for the Determination of PCBs in Transformer Oil Samples-Application on Real Samples from Botswana

Saidy Motladiile, Habauka M Kwaambwa and Kwenga Sichilongo

A procedure in which a retention time window for the determination of polychlorinated biphenyls (PCBs) congeners including those not presented in this study but of similar molar masses in transformer oil has been developed and validated. This procedure was successfully applied in the determination of transformer oil samples from Botswana for comparison with a preliminary inventory for PCB levels in transformer oil and other receptacles suspected to contain PCBs and developed during the formulation of the Botswana National Implementation Plan (NIP) for the sound management of persistent organic pollutants (POPs). Recoveries in the developed procedure initially meant for 39 PCB congeners ranged from 44.53±0.31 to 111.93±4.75% uncorrected for bias, while linearities i.e. r 2 values ranged from 0.9624 to 0.9999 with method detection limits (MDLs) varying from 0.02 to 0.13 ppm (w/v). Application of this procedure on real samples from Botswana showed that the transformer oil contained no PCBs although the preliminary data using screening equipment and kits for indicative inventory data showed high PCB contents in some cases of as much as 456 ppm (w/v). It is proposed here that this method be adopted in the SADC region for confirmation of presence and determination of the levels of PCBs where they are detected in order to improve on the preliminary inventories that were developed during the NIP development exercise for the Stockholm Convention (SC) in these countries.