Pesticides

Our lab has been working for a number of years on measuring pesticide residue levels in market vegetables. We have an interest in facilitating the easy screening of vegetables in a way that will encourage broader testing, especially in situations (such as developing countries) where pesticides are of particular concern.

Our current work is focusing on developing a novel combination of techniques for simple screening of pesticides in market vegetables. This technique combines the QuEChERS technique for extraction with ELISA for a semi-quantitative assessment of organophosphate/carbamate presence. As an example application, we screened local organic vegetables from both the farmer's market and a large supermarket for OP/C. This work follows up on pesticide monitoring work performed in Cambodia (see article below).

Major Findings:

• Extracts made using QuEChERS can effectively be tested using an OP/C ELISA detection screen.
• This technique is appropriate for relatively quick, simple, and inexpensive screening of pesticides in vegetables (and likely other matrices).
• 1 out of 8 tomato samples from the local farmer's market screened positive with the OP/C test; this sample was "certified naturally grown". Neither of the 2 private garden tomato samples tested positive.
• 1 out of 4 organic tomato samples from local supermarket chains screened positive with the OP/C test.
• The test has a high sensitivity, and those samples testing positive for residues were likely well below levels of health concern. Sources of residues on these organic vegetables are not known.

Future Work:

• Future screening with clarify whether there is a difference in OP/C presence in organic vegetables from farmer's markets vs large supermarkets.
• We hope to test this technique as an appropriate test alternative in situations where capacity and resources are limited (such as in Cambodia).

Student researcher (2011-13): Nels Akerson