Methods for Analysis of the California List of Pesticides in Cannabis

This article from Issue 10 of the Analytix Reporter, produced by Merck, describes methods using both GC-MS/MS and LC-MS/MS to determine pesticides in cannabis with a special focus on matrix effects and the use of internal standards.

Abstract
Methods to quantify the California list of pesticides from dried cannabis (hemp), using both GC-MS/MS and LC-MS/MS are described with a special focus on evaluation of matrix effects and use of internal standards.

Introduction
Growers and processors of cannabis must show their products to be safe as per individual state requirements. Generally, requirements include testing to ensure that the cannabis flower is free of pesticides. In this application note we demonstrate how Supelco analytical standards, instrument consumables, and reagents can be used to analyze low levels of pesticides in cannabis and, in particular, the 66 pesticides required by the State of California.

Methods
For full details, please download the article.

Conclusion
A method has been developed to quantify the California list of pesticides from dried cannabis (hemp), in accordance with the state requirements, utilizing a combination of both LC-MS/MS and GC-MS/MS. A single step, flow-through (interference removal) solid phase extraction cleanup is used to prepare sample extracts for both instrumental techniques. The linearity, recovery, and precision were satisfactorily achieved (not shown) and schemes for performing calibration, extraction recovery, and suppression/enhancement studies are provided.

A total of 57 pesticides were reported by LC-MS/MS and 40 using GC-MS/MS. Due to high levels of interfering CBDA, one analyte, acequinocyl, was not detectable at minimum levels with the existing instrumentation. All other pesticides were reported with one or the other analytical technique to meet or exceed current California regulatory limits for each category. It is shown that a combination of GC-MS/MS and LC-MS/MS instrumentation provides an efficient way to analyze cannabis for pesticides.

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