Overcoming Challenges associated with analysis of all of pesticides regulated by California

Posted by

Analytical Cannabis

With the passing of the 2018 Farm Bill legalizing hemp and different US states legalizing Cannabis products, farmers are allowed to grow cannabis and hemp. Like any other agricultural crop, pesticides are applied to cannabis and hemp plants to protect it from pests and improve growth yield. Chronic exposure to pesticides can lead to serious health risks and therefore pesticide analysis in Cannabis and hemp is important for consumer safety and quality control. Among all of states in USA, California has issued most stringent action limits for 66 pesticides residues in cannabis flower, cannabis infused edibles, concentrates and hemp. Normally pesticide analysis in cannabis and other food matrices is done by both GCMSMS and LCMSMS since some nonpolar and chlorinated pesticides such as pentachloronitrobenzene, chlordane and others are difficult to ionize with electrospray source used in LCMSMS systems. We would demonstrate how we measured these compounds at low levels using LCMSMS with APCI source. The ionization mechanism of chlorinated pesticides such as pentachloronitrobenzene and others using LCMSMS system with APCI source would be presented. We analyzed all of 66 pesticides (including very hydrophobic and chlorinated pesticides typically analyzed by GCMSMS) spiked in hemp and cannabis samples well below the action limits specified by California State. Hemp and cannabis matrix is challenging and therefore it causes ion suppression and matrix inference for response of some of pesticides. We would demonstrate approaches to mitigate these matrix effects from cannabis and hemp. Sample preparation is the main bottleneck for achieving the high throughput analysis of pesticides in cannabis/hemp testing labs. For sample preparation, we used solvent extraction since it is a quick, cheap and easy way to achieve high extraction recovery in comparison to other time-consuming sample preparation techniques like solid phase extraction (SPE) and QuEChERS. Also, the performance of LC-MS/MS method was checked by conducting blind emerald scientific’s proficiency test for 66 pesticides in hemp. The proficiency test report generated with LCMSMS method showed acceptable results for all of 66 pesticides in hemp with no false positives and negatives.