Determination of Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans by Exhaustive Chlorination Method

Abstract

A method of quantitative determination of minute amount of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), complex mixtures of isomers, was described. PCDD and PCDF (1-10μg) were exhaustively chlorinated to octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) by heating with perchlorinating agent at 68-69°C for 2 hours. The perchlorinated compounds were quantitated by gas chromatography equipped with an electron capture detector using XE-60 as a liquid phase. Yields of perchlorinated compounds from dibenzo-p-dioxin and dibenzofuran both having two or more chlorine atoms were more than 75%, while from those having no or one chlorine were 4-16%. This method was also applicable to quantitation of polychlorinated biphenyls.
By this perchlorination method, the contents of PCDD and PCDF in pesticide PCP, Kanechlor (KC) and Yusho oil were determined. From two brands of PCP, 430 and 0.6μg/g of OCDD and 290 and 1.3μg/g of OCDF were quantitated, respectively. Only PCDF were detected in KC-300, KC-400, KC-500, KC-600 and Yusho oil (3 samples), and their estimated contents calculated from the amounts of OCDF produced were 1.5, 16.6, 2.5, 2.7 and 4.9μg/g, respectively.