In the agricultural community, there are thousands of pesticides that could be potentially used to protect crops against a wide range of pests and fungi, providing preservation qualities. While many pesticide classes enhance the productivity of agriculture, there are also many residues that pose a potential risk for human health due to their subacute and chronic toxicity. Thus, it is important to control or regulate the uses of pesticides in crop production and to also monitor their levels for compliance to ensure the safety of the food supply for the general public.

In a recent paper published in Journal of Food and Agricultural Chemistry (J. Agric. Food Chem. (2017) 65, 473,493) by J.Wang et al., (Canadian Food Inspection Agency, Calgary, Canada), UCT’s Enviro Clean QuEChERS Pouches containing 6.0 g anhydrous magnesium sulfate (MgSO4) and 1.5 g anhydrous sodium acetate were used in conjunction with Enviro Clean 15mL dSPE centrifuge tubes containing 900 mg MgSO4, 150 mg C18 and 300 mg primary secondary amine (PSA) for the development and validation of  a semiautomated qualitative method for target screening of 448 pesticide residues in fruits and vegetables using UHPLC/ESI Q-Orbitrap.  Full MS/dd-MS2 (data dependent acquisition) was used to acquire product-ion spectra of individual pesticides to build a compound database/MS library.

This extraction methodology was utilized for sample data acquisition from fruit and vegetable matrices fortified with pesticides at 10 µg/Kg and 100 µg/Kg for target screening purpose. Accurate mass, retention time and response threshold were three key parameters in a compound database that were used to detect incurred pesticide residues in samples. The validated target screening method is capable of screening at least 94% and 99% of 448 pesticides at 10 µg/Kg and 100 μg/Kg, respectively, in fruits and vegetables without having to evaluate every compound manually during data processing. This significantly reduces the worktime of analysts in routine practice. Click here to view all of UCT's available QuEChERS sorbent and salt combinations.