Gas chromatography-ion trap tandem mass spectrometry versus GC-high-resolution mass spectrometry for the determination of non-ortho-polychlorinated biphenyls in fish.

Gas chromatography coupled with ion trap tandem mass spectrometry (GC-MS-MS) has been compared to gas chromatography-high-resolution mass spectrometry (GC-HRMS) for the analysis of non-ortho-chlorinated biphenyl (CB) congeners in fish samples. The MS-MS operating parameters related to the isolation and fragmentation of the precursor ions by resonant collision induced dissociation (CID) were optimised in order to achieve maximum sensitivity and selectivity. Analytical procedure consisting of Soxhlet extraction, clean-up using a multilayer silica column and the isolation of the target compounds with SPE commercial carbon cartridges packed with Carbopack B has been applied. Quality parameters have been established using standard solutions and fish samples. Good repeatability, long-term precision (lower than 10%), and limits of detection between 0.12 and 0.16 pg g(-1) were obtained. The effect of potential interfering compounds such as polychlorinated naphthalenes in the quantification of non-ortho-CBs has been investigated. Using selective CID fragmentation conditions, the effect of these compounds was minimised. The GC-MS-MS method was validated by comparing the results with those obtained in two European intercomparison exercises.