Alkyl polychloronaphthalenes

In addition to chlorocymenes and chlorocymenenes, four groups of persistent alkylaromatk chlorohydrocarbons have been detected and characterized from chlorobleaching of pulp. They were assumed to be planar aromatic chlorocom-pounds (PLAC) because they were found in cleanup fractions of PCDDs and PCDFs after reversed elution with toluene from a carbon column [39]. PLAC groups were alkyl-polychloronaphthalenes (RPCN), alkyl-polychlorobibenzyls (RPCBB), alkyl-polychlorofluorenes (RPCFL), and alkyl-polychlorophenan-threnes (RPCPH). Among the latter, chlororetenes are most abundant [40]. 

Occurrence of alkyl polychloronaphthalenes (RPCN) in spent bleach liquors was first time reported in 1979 [8], Their structure was deduced to contain one methyl and one isopropyl group [8] which indicates origin from wood. Later analyses indicated that most common RPCNs in kraft pulp mill effluents and sludges were mono- to tetramethyl polychloro naphthalenes (C1-4PCN) [41-45]. In sludges their total contents were 28-72 ng g1 dw and in effluents only trace levels of a few ng 1 1 [42, 45]. Their origin was suggested to be chlorination of alkyl naphthalenes abundant in oil-based defoamers used in pulp mills [42]. 

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