Abstract
Polychlorinated naphthalenes (PCNs) are pollutants often found in environmental samples. Only limited standards of individual PCN isomers are 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 an atomic emission detector (AED), which can detect PCNs with a sensitivity proportional to the number of chlorine atoms in the molecule. Congeners of Halowaxes were identified by measuring the carbon to chlorine ratio. Isomers were identified according to the reported elution order. The amount of each congener was determined from the peak area of chromatogram measured for the emission of chlorine. The relative sensitivities were evaluated for the congeners lacking quantification standards using 1, 2-dichloronaphthalene, 1, 2, 3, 4-tetrachloronaphthalene and octachloronaphthalene. Thus, the congeners constituting each Halowax were determined and the total concentrations were in the range of 93103 % of the calculated value. The isomer composition was almost the same as the value given by MS measurement.
