Analysis of pesticide residues in bananas harvested in the Canary Islands (Spain)

In this work, 11 pesticides (ethoprofos, dimethoate, diazinon, malaoxon, chlorpyrifos-methyl, fenitrothion, malathion, chlorpyrifos, fenamiphos, buprofezin and phosmet) were analysed in 57 banana samples taken from the local markets of the Canary Islands (Spain). Analyses were carried out by the QuEChERS approach developed for pesticide residue analysis in food, using gas chromatography (GC) with nitrogen-phosphorus detection (NPD). Triphenylphosphate (TPP) was used as internal standard. Recoveries ranged between 67% and 118% with RSD values below 16%. Typical limits of quantification (LOQs) of the method were 0.01-0.14 mg/kg, which are below the EU maximum residue limits (MRLs) established for these compounds in bananas. Chlorpyrifos was detected in 50 samples (88%) in the concentration range 0.03-0.65 mg/kg, malathion in five samples (8.8%) in the concentration range 0.16-0.17 mg/kg, fenitrothion in four samples (7.0%) in the concentration range 0.02-0.10 mg/kg and buprofezin in one sample (1.8%) at 0.15 mg/kg. All these values are below the MRLs established for these compounds except for two samples containing fenitrothion. Among the studied pesticides only chlorpyrifos has a high occurrence in the samples. However, the levels of these residues cannot be considered a serious public health problem according to EU regulations. Because of the high occurrence of chlorpyrifos, its distribution between the pulp and the peel was also investigated. Results show that most of the pesticide remains in the peel and that only amounts between 0.07 and 0.12 mg/kg occur in the pulp even at concentrations in the peel as high as 0.87 mg/kg. (C) 2008 Elsevier Ltd. All rights reserved.