Studies on residues of insecticide used to spray pineapples grown at Samsam in the Amasaman District (Ghana)

The residues resulting from the misuse of pesticides on fruits are a major concern in many countries as well as in Ghana. On the other, the use of pesticides is one of the important measures of modern agricultural practices in protecting the crops from different pests. However, the hazards to health can be minimized to a great extent if these residues are kept below their prescribed safe level. A field survey was conducted at Samsam in Amasaman District regarding the type of insecticide used by local farmers on pineapples. In order to assess the residue level of insecticide in fresh fruits; samples were collected at harvest from the fields of farmers at two sites. The analysis of insecticide was limited to the treatment history obtained from the fruit growers. The blended epicarps and mesocarps were extracted with ethyl acetate. The extracts were cleaned up (purified) by using florisil adsorption column chromatographic method. The purified extracts from epicarps and mesocarps were concentrated and analysed separately by a reversed phase HPLC isocratic method with 60% methanol and 40% water mixture as the mobile phase. Only two out of 20 samples (10 epicarps and 10 mesocarps) were contaminated with certain levels of chlorpyrifos and the residues levels were above European Commision (E.C.) Maximum Residue limit (MRL) set (2006) for pineapple. The MRL set by European Commission (2006) is 0.05mg/kg but the residue levels detected were 0.18mg/kg and 0.13mg/kg representing 10% of sampled pineapples analysed