Dr. Emanuela Gionfriddo, an assistant professor of analytical chemistry at The University of Toledo, created a more reliable, robust and efficient way to monitor pesticide exposure and help protect the health and safety of agricultural workers, especially for emerging sectors like the cannabis industry. Credit: Daniel Miller, The University of Toledo
Pesticide exposure is a major health concern for farmers, including in emerging areas of agriculture such as cannabis farming. Fully understanding the exposure risks for these newcomers to the industry, as well as secondhand exposure risk for their household members, requires fast and sensitive clinical testing methods that can detect trace amounts of multiple chemicals. Researchers from the University of Toledo have developed a new, robust, automated method to quantify exposure to 79 different pesticides in human blood plasma with higher sensitivity and throughput than traditional methods.
The method involves the use of an automated, biocompatible solid-phase microextraction (SPME) technique as an alternative to manual QuEChERS extraction for sample preparation prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS). Specifically, the researchers used a hydrophilic-lipophilic balance/polyacrylonitrile (HLB/PAN) phase to extract the pesticides from human blood plasma with minimal matrix effects. The team tested common pesticides used in cannabis cultivation for the study, and compared the SPME preparation method with a QuEChERS method for extraction of pesticides from complex matrices.
Both sample preparation methods enabled the extraction and simultaneous analysis of 79 pesticides by LC-MS/MS. SPME performed similarly to QuEChERS regarding accuracy and precision, but achieved higher sensitivity, with the ability to detect trace pesticide levels down to parts per trillion. The SPME-LC-MS/MS method also resulted in much fewer matrix effects than the QuEChERS-LC-MS/MS method. Additionally, the ability to couple the automated SPME system to the LC-MS/MS improved speed and throughput, reducing preparation time per sample to just 1.7 minutes, according to corresponding author Emanuela Gionfriddo. This research was published in the journal Analytical and Bioanalytical Chemistry.
“Assessing pesticide exposure quickly and thoroughly is crucial for the health and safety of workers and their families, to correct malpractices in pesticide storage and application, and to prevent further exposure,” said first author Nipunika H. Godage. “Our new method can extract and analyze simultaneously a wide variety of pesticides from human plasma.”
Farm workers can be exposed to pesticides during processes such as mixing or application, through the skin or respiratory tract, especially when proper personal protective equipment and safety procedures are not used. Secondhand exposure can also occur when pesticides residues on workers’ skin, clothing or other items make it into their home, which can impact other household members, including children. High-throughput, sensitive methods such as SPME-LC-MS/MS may aid in larger studies of pesticide exposure risk in newer sectors, such as cannabis.