Uncertainty measurement of chlorophenols and PCBs analyzed in aqueous media by SPME-GC-ECD

Chlorophenols (CPs) and polychlorinated biphenyls (PCBs) are two of the most important groups of high-priority pollutants, due to their carcinogenicity, toxicity, and mutagenicity. This paper compares the utilization of two solid-phase microextraction (SPME) based extraction procedures, prior to gas chromatography with electron capture detection (GC-ECD), to determine PCBs (PCB 101 and PCB 153) and CPs (2,4,6-TCP and PCP) in aqueous media. Good linearity was observed with the SPME-GC-ECD method for the concentration range studied; detection limits ranged from 0.5 to 1.0 microg/L. Repeatability was between 13% and 31% for the lowest concentration and between 5.6% and 7.8% for the highest concentration. The uncertainty was determined by Thompson and bottom-up approaches. The identification of the compounds was confirmed by GC-MS. The developed procedure has the advantage of simplicity of sample treatment and avoids the use of potentially hazardous organic solvents and the clean-up or pre-concentration steps. Regarding PCBs, this procedure is simpler and faster, but the limits of detection are higher.