Okra is an important vegetable of the tropical countries and most popular diet component in different countries including India. According to the Food and Agriculture Organization of the United Nations (FAO)1, India is the second largest producer of this vegetable in the world and it produced approximately 5,800 tones of okra in 2010-11. Okra is susceptible to a variety of pests and diseases. A wide range of pesticides are used to treat okra plants in India2. Legislative limits are in place for the presence of pesticides in domestically produced, imported, or exported okra3. It is, therefore, very important to monitor commonly used pesticides at legislative limits.
A multi residue analysis method for the detection of 250 pesticides in okra will be presented. Samples were extracted using either acetate or citrate buffered QuEChERS methods. The extracts were subjected to a dispersive solid-phase extraction using different combinations of MgSO4, PSA, GCB and C18 to determine the most appropriate method to further clean the okra extracts prior to analysis. Ultra performance liquid chromatography coupled with tandem quadrupole mass spectrometry with 2 MRM transitions per compound were collected for all pesticides in either ESI+ or ESI- mode using rapid polarity switching. Simultaneous full scan data was acquired in order to assess any matrix effects. Product ion confirmation scans were also acquired simultaneously to confirm pesticide identifications. For all pesticides, limit of detection (LOD), limit of quantification (LOQ) and recoveries at 10 µg/kg will be presented.