Validation of a congener specific method for Ortho and non-Ortho substituted polychlorinated biphenyls in fruit and vegetable samples

An on-line procedure has been developed and validated for the clean-up and fractionation of ortho and non-ortho-PCBs in fruit and vegetable samples. The procedure combines silica/acid and carbon/glass fibre columns with gas chromatography-mass spectrometry. Chromatography on carbon/glass fibre allowed collection of mono-ortho/di-ortho and non-ortho-PCB fractions, which were determined separately by GC-MS. The method was validated by replicate analyses and by inter-laboratory comparison of data for PCB congeners determined in fruit and vegetable samples collected in South Wales. The concurrent determination of ortho and non-ortho substituted PCBs is reported with recoveries ranging from 55–95% and a mean intea-laboratory precision (%COV) of 9.5% for apple extracts.