STM Article Repository

A monitoring project for pesticide residues in orange samples in Al-Tamer vegetables market, Riyadh was conducted. A total of 144 samples of organic and non-organic orange were collected according to the Codex Alimentarius recommendations. Samples were extracted with acetonitrile and subjected for clean-up using Florisil column. Clean extracts were analyzed using GC-MS against 86 pesticides of concern. Method performance parameters are reported. Organic orange samples of both countries contained non-detectable amounts of the tested pesticides. For the non- organic produce samples it contained varying amounts of pesticides depending on the season, country and month. Mostly, insecticides were dtected mostly in the samples then fungicides. Violating pesticides were also the anti-insect ones. Methomyl was the violating compound in South African orange and ethion in Egyptian one. Fungicides were below the corresponding MRL. Total amount of residues were the maximum in December 2010 (5.16 mg/kg) followed by November 2010 (4.27 mg/kg) of which ethion was the major constituent, this may be due to insect control practices. The highest level of residues appeared in the November 2011 with 1.68 mg/kg residues of Methomyl followed by august 2011 with 1.3m mg/kg consist of Methomyl and Chlorpyrifos-methyl.