Ensuring Consumer Safety with Certified Reference Materials, Applications and PT Studies for Pesticide Testing in Cannabis

Markus Obkircher, Research & Development, Merck KGaA, Buchs, Switzerland (markus.obkircher@merckgroup.com)

Since the presence of pesticides in Cannabis and similar matrices is known and growing problem, fast and sensitive LC-MS methods were established for Cannabis testing to ensure consumer safety. Therefore, the access to well characterized reference materials for a precise and accurate quantitation of these compounds has become an increasing need in the market. These reference materials should be characterized and prepared according to ISO/IEC 17025 and ISO 17034. In order to achieve certification according to this double accreditation at the highest metrological level, different methods need to be successfully established at the reference material provider.

The customer has the choice of two different formats – neat materials or ready-to-use solutions, which both have their advantages. For the development of neat compounds that can be supplied in larger amounts, quantitative NMR (qNMR) is the application of choice since it offers direct traceability to SI. On the other hand, pesticide mixtures offer an easier application in the laboratories of the user. For this purpose, a completely new approach was introduced that combines qNMR together with Isotope Dilution MS (IDMS) to offer these materials in solution and still assuring homogeneity and stability of the materials throughout the entire shelf life of the product.

For best analytical results, CRMs are utilized according to developed application procedures and accuracy can be controlled through participation in specifically designed proficiency testing studies.

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Short Biography of Presenting Author

Markus Obkircher is Director R&D heading Merck’s Reference Materials and Proficiency Testing division with teams in the US and Switzerland. He is responsible for the in-house development of new analytical standards and certified reference materials under ISO/IEC 17025 and ISO 17034 double accreditation. Prior to this position he was R&D Manager in Buchs, Switzerland, with a strong focus on synthesis, characterization and certification of reference materials. He joined Merck / Sigma-Aldrich nine years ago after heading the development unit for a custom API manufacturer. He completed his post-doctoral studies at Harvard in Boston and his PhD thesis in Basel, and further holds an executive MBA degree from the University of Zurich.