NIRE Annual Report		1998

Objectives

Polychlorinated naphthalenes (PCNs) are widely contaminating the environment as well as polychlorinated biphenyls (PCBs). Major sources of PCNs are industrial products in the past and unexpected emission from incinerators. Isomer specific analysis of PCNs is very important to evaluate the risk of PCNs, because several isomers have toxicity similar to dioxins, however, several isomers are not resolved by gas chromatography using general columns. We tried to separate these isomers using fused silica capillary columns with structural selective stationary phases such as cyclodextrin or liquid crystalline containing stationary phase.

Results

Hexachloronaphthalene(HxCN) isomers elute on usual weekly polar columns by following order:

(1) 1,2,3,4,6,7-/1,2,3,5,6,7-HxCN
(2) 1,2,3,4,5,7-/1,2,3,5,6,8-HxCN
(3) 1,2,3,5,7,8-HxCN
(4) 1,2,4,5,6,8-/1,2,4,5,7,8-HxCN
(5) 1,2,3,4,5,6-HxCN
(6) 1,2,3,4,5,8-HxCN
(7) 1,2,3,6,7,8-HxCN

Isomer pair (2) was resolved using -DEX 120 column, and isomer pair (4) was resolved using -DEX 120 column. On SB smectic column, which has liquid crystalline containing stationary phase, elution order have changed greatly to following order:

(1) 1,2,3,4,6,7-/1,2,3,5,6,7-HxCN
(2) 1,2,3,5,6,8-/1,2,4,5,7,8-HxCN
(3) 1,2,3,4,5,7-HxCN
(4) 1,2,4,5,6,8-HxCN
(5) 1,2,3,5,7,8-HxCN
(6) 1,2,3,4,5,8-HxCN
(7) 1,2,3,4,5,6-HxCN
(8) 1,2,3,6,7,8-HxCN

Thus all HxCN isomers except for 1,2,3,4,6,7-/1,2,3,5,6,7- can be measured by combining the results from -DEX 120 and -DEX 120 column, or SB-smectic and general weekly polar column.

Selected Publications

1)	Estimation of emission sources of polychlorinated naphthalenes using finger-print method for isomer compositions, Journal of Environmental Chemistry 6, 495-501,1996
2)	Gas chromatographic isolation of 1,2,3,4,5,7-, 1,2,3,5,6,8-, 1,2,4,5,6,8- and 1,2,4,5,7,8-hexachloro-naphthalene, Chemosphere 35, 1195-1198, 1997

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