DUAL-COLUMN GC ANALYSIS OF MEDITERRANEAN FISH FOR 10 ORGANOCHLORINE PESTICIDES AND 62 CHLOROBIPHENYLS

The simultaneous analysis of alpha-HCH, beta-HCH, gamma-HCH, HCB, p,p' -DDD, p,p'-DDT, p,p'-DDE, o,p'-DDT, mirex, dieldrin and 62 chlorobiphe nyl congeners on two parallel capillary GC columns of different polari ty is described for nine Mediterranean fish species. Ten commercially available columns with stationary phases completely characterized in r espect of their PCB elution patterns were considered for dual-column G C-ECD analysis. The combination of a 60 m x 0.25 mm i.d. column coated with a 0.25 mum film of 50 % diphenyl dimethylsiloxane and a series c ombination of a 25 m x 0.25 mm i.d. column coated with a 0.25 mum film of 5 % diphenyl dimethylsiloxane with a 25 m x 0.22 mm i.d. column co ated with a 0.10 mum film of 1,10-dicarba-closo-dodecarborane dimethyl polysiloxane furnished the highest number of separated chlorobiphenyl congeners (104). The dual-column GC system performed with high stabili ty and reproducibility over a broad concentration range (1-3000 ng/g l ipid) of the organochlorine compounds in the investigated fish.