Analysis Of Pesticide Residues In Maize And Beans Types In Lagos Markets

ABSTRACT

Pesticides used in agriculture for the control of various pests often leave residues in foodstuffs and these have been shown to pose health hazards. Analysis of pesticide residues in food is one way to determine the level of human exposure to these chemicals and hence their potential human health hazards.

Maize (Zea mays L.) and beans (Phaseolus vulgaris L.) samples purchased from different markets in Lagos State were analyzed for residues of organochlorine, organophosphate and carbamate pesticides. Analysis was done using gas chromatograph with mass spectrometric detector (GC-MS) after careful extraction and cleanup.

Most of the maize samples (%) were found to contain residues of one or more pesticides with concentrations ranging from 22-3951.0 pkg. The white types of maize contained higher concentrations of residues than the yellow types. Three classes of pesticides were detected in maize. All the samples of beans analyzed contained at least one pesticide residue (100% incidence). White beans were found to contain higher concentrations of residues than the brown types. The concentrations of organochlorine, organophosphate and carbamate pesticides residues in beats ranged from 2.3-1480.5ug/kg

The most commonly found residue among both maize and beans samples was the organophosphate, pirimiphos-methyl. Its percent occurrence was 43 in maize and 54 in beans. There was a decline in the mean levels of organochlorine pesticides in both maize (6.9-41.3kg) and beans (4.8-79.7g) compared to the results of a previous similar study (10.0-93.xpg for male and 25.0-303 Oug/kg for beans)