DETERMINATION OF CONGENER COMPOSITION OF HALOWAX USING ATOMIC-EMISSION DETECTOR

Polychlorinated naphthalenes (PCNs) are pollutants often found in envi ronmental samples. Only limited standards of individual PCN isomers ar e available. 'Halowax' is the most popular technical PCN mixture, but the composition is not clear. In this study, a method to determine the congener composition of a PCN mixture was established using GC with a n atomic emission detector (AED), which can detect PCNs with a sensiti vity proportional to the number of chlorine atoms in the molecule. Con geners of Halowaxes were identified by measuring the carbon to chlorin e ratio. Isomers were identified according to the reported elution ord er. The amount of each congener was determined from the peak area of c hromatogram measured for the emission of chlorine. The relative sensit ivities were evaluated for the congeners lacking quantification standa rds using 1,2-dichloronaphthalene, 1,2,3,4-tetrachloronaphthalene and octachloronaphthalene. Thus, the congeners constituting each Halowax w ere determined and the total concentrations were in the range of 93 ap proximately 103% of the calculated value. The isomer composition was a lmost the same as the value given by MS measurement.