期刊名称：Research Journal of Environmental and Earth Sciences
印刷版ISSN：2041-0484
电子版ISSN：2041-0492
出版年度：2010
卷号：2
期号：3
页码：133-138
出版社：Maxwell Science Publications
摘要：In this study, the levels of organochlorine pesticide residues in the Densu basin have been investigated using fish sam ples as a case study. Six fish species namely Heterotis niloticus , Channa obscura , Hepsetus odoe , Tilapia zilli , Clarias gariepinus and Chrysichthys nigrodigitatus were collected from the sampling towns, Weija and Nsawam along the Densu river basin in the Greater Accra Region of Ghana. Composite samples w ere homogenized, freeze dried and ground to obtain powdered samples. The powdered samples were extracted by soxhlet extraction procedure using (3:1) hexane: acetone mixture. The extracts were cleaned-up using florisil adsorbent and characterized for organochlorine content using Gas Chromatography (GC) equipped with Electron Capture Detector (ECD). The GC recoveries of spiked samples were between 80 to 96%. Fourteen organochlorines (OCs) namely gamma-HCH, delta-HCH, heptachlor, aldrin, gammachlordane, p,p'-DDE, alpha-endosulfan, dieldrin, endrin, endrin-aldehyde, endosulfan-sufate, p,p'-DDT, endrinketone and methoxychlor were identified and quantified. A 100% incidence was recorded for gamma-HCH, delta-HCH, heptachlor, aldrin, gamma-chlordane, alpha-endosulfan, dieldrin and p,p'-DDT, while 75% incidence was recorded for the metabolites, p,p'-DDE and endosulfan-sulfate. The concentrations of OCs ranged from 0.3 to 71.3 :g/kg and were however, below the Australian Maximum Residue Limits (MRL) of 50 to 1000 :g/kg for fresh w ater fish.
