CHARACTERIZATION OF POLYCHLORINATED TERPHENYL MIXTURES BY HIGH-RESOLUTION GAS-CHROMATOGRAPHY AND TANDEM MASS-SPECTROMETRY

We have investigated the capacity of high resolution gas chromatograph y/tandem mass spectrometry in the multi-reaction monitoring mode to st udy the distribution of polychlorinated terphenyls (PCTs) In commercia l mixtures and environmental samples, Collision energy and collision-g as pressure have been optimized using a hybrid instrument for maximum sensitivity and selectivity, Product ion and precursor-ion spectra of PCTs have been obtained, The internal interferences observed in the de tection and measurement of the [M](+.) ions due to [M-2Cl](+.) fragmen t ions from the terphenyl homologues with two additional chlorine atom s have been mainly eliminated using tandem mass spectrometry with sele cted reaction monitoring of the loss of two Cl-35 atoms. This procedur e has been used to determine the homologue distribution of PCTs in com mercial mixtures such as Aroclor 5432, 5442, 5460 and Leromoll 141, an d in samples of shellfish and tuna.