METHYL LINDANE AND OTHER ANALOGS OF HEXACHLOROCYCLOHEXANE IN DAB AND PLAICE FROM THE MERSEY ESTUARY

Electron impact and chemical ionisation mass spectrometry used in conj unction with H-1 and C-13 NMR indicate the presence of methyl lindane (1 alpha,2 alpha,3 beta,4 alpha,5 alpha,6 beta-hexachloro-1-methyl cyc lohexane) (MHCH) in muscle tissue of the demersal flatfish, dab (Liman da limanda) and plaice (Pleuronectes platessa), from the Mersey Estuar y and inner Liverpool Bay. At least thirteen other peaks occur in the hexachlorocyclohexane (HCH) region cf the gas chromatograph traces of muscle tissue of Mersey fish, all of which are thought to je other chl orinated homologues or isomers of MHCH. Concentrations of the methyl l indane isomer and its close relatives (Sigma MHCH) in fish muscle show a clear gradient from the inner Mersey Estuary outwards into Liverpoo l Bay. (C) 1997 Elsevier Science B.V.