GC-MS Determination of Polychloro Biphenyls in Cosmetic Lotion with Stirring Rod Adsorptive Extraction

A method of GC-MS with stirring rod adsorptive extraction for the determination of 7 polychloro biphenyls (PCB′s) in cosmetic lotion was proposed. Influential factors of the extraction process, including extraction time, extraction solvent and its amount, thermodesorption time and cold injection temperature were studied by orthogonal testing. DB-5MS capillary chromatographic column was used in GC, and the full scanning monitoring with electron impact ionization source was adopted in MS. Linear relationship between values of peak area and mass fraction of PCB′s was obtained in definite ranges, with lower limits (10S/N) of determination in the range of 5-60 ng·kg-1. Tests for recovery and precision were made at 3 concentration levels, giving results of recovery in the range of 74%-107%, with values of RSD′s (n=6) in the range of 1.1%-16.9%.