Food safety: Overcoming the challenges of pesticide analysis

In this SelectScience^® interview, we speak with Dr. Ingrid Hayenga, global product manager for environmental standards at Merck, about the importance of effective pesticide analysis to ensure food and environmental safety. Hayenga reveals how she introduces new analytical standards and certified reference materials (CRMs) to the market and outlines the portfolio of pesticide reference materials offered by Merck, designed to help customers remain compliant with the strict regulations that continue to surround the food industry. Hayenga also highlights how Merck helps customers overcome common challenges, explains the need for CRMs, and shares her thoughts on the future of pesticide analysis.

Tell us a bit about yourself and your role at Merck

IH: I got my university degrees at the WWU-Münster in Germany, worked as a postdoc at the University of Alberta, Edmonton in Canada and then moved back to Europe. Now I am based in Buchs, Switzerland, where I work as a global product manager for the environmental reference material portfolio at Merck, which includes the reference materials for pesticides, organic pollutants, and the metal solutions for atomic spectroscopy (ICP and AAS).

As the product manager, I am responsible for product planning and its placement in the market throughout the whole lifecycle of a product. Supporting our customers in their daily work and being able to supply them with the reference standards they need and can trust, e.g., pesticides for food analysis, is the central pillar of my work. In order to achieve this, I work closely with our research and development, procurement, sales and other departments worldwide. Besides observing regulatory and market trends, customer feedback and interaction is a very important aspect of this undertaking, whether through customer visits, webinars, seminars or at conferences. These are all facets I consider in order to keep my product portfolio active and current.

What challenges are your customers currently facing?

IH: Our customers face a range of different challenges: a growing target list of analytes due to increasing and tightening of regulations, e.g. in Europe the need for lower limits of detection originating from different national regulations, and also the increasing global food trade. Because of the latter, global food trade companies would like to measure “everything in everything”. In addition, there are pesticides, to name an example, that are not approved in all regions of the world. Hence regulatory and contract labs are facing more unusual and complex matrices, e.g., botanicals, tea, cocoa, spices and a wider range of target analytes to look out for. As the majority of these labs are accredited according to ISO/IEC 17025, they have to use certified reference materials (CRM) for the quantification of the analytes or the method or instrument validation, whenever a CRM is available. This poses another problem, as reliable CRMs are not available for every pesticide and its metabolite(s).

How does Merck help overcome these challenges?

IH: In regard to the large variety of pesticides that food testing labs need to analyze, Merck supports this work by offering a portfolio of reference materials for different pesticides, metabolites and isotopically labeled compounds. We also provide these products in different formats such as neat materials, single solutions, solution mixes or matrix materials. These reference materials are classified into five major categories based on their quality grades, from the highest grade, the national metrology and other primary standards via CRMs, reference materials, analytical standards, to research-grade or research chemicals. The certification and traceability requirements increase from the research grade to the top level, the primary reference materials issued by national metrological institutes.

Talking about matrix materials, we have recently expanded this portfolio by introducing Fapas^® Reference Materials to make it easier for customers to do an in-house performance check of their methods, not only for pesticides. As it happens, we were the first commercial company to use quantitative NMR (qNMR) for the certification of neat reference materials. In order to guarantee the highest reliability of our TraceCERT^® CRMs, we apply a multi-component approach, which involves determining the certified value with quantitative NMR (qNMR) and confirming it by extended analytical data including impurity determination. Extensive stability and homogeneity tests are also performed for every certification. All uncertainty contributions are illustrated in a cause-effect diagram and included in the reference material certificate as well as the whole certification process.

What are the key standout features of your pesticide reference materials?

IH: In a nutshell, we offer

• A broad and continuously expanding portfolio of pesticides and metabolites, also isotopically labeled
• Different formats: neat, solution, mixes, in matrix, proficiency testing (PT) schemes
• Different quality grades fitting the customer’s application need (from analytical standards, via CRM, to primary reference material from national metrological institutes like NIST or JRC)
• Food matrix material from Fapas^®

What are the benefits of these products compared to other conventional approaches?

IH: The portfolio and the various formats Merck offers: our customers have a broad selection to choose from. Regarding the various quality grades we offer, our customers can rely on our thoroughly tested, characterized and clearly documented substances, as well as on a comprehensive certificate of analysis (CoA) with all the required and relevant information. For example, for our PESTANAL^® product line, which we issue as analytical standard grade, we state the purity and identity on our CoA. This grade is well suited for a pesticide identity check in food, but with some in-house certification can also be used by testing laboratories for assay determinations. The TraceCERT^® line of pesticides, the CRMs Merck offers, should be used when traceability to an SI unit and highly accurate reference materials with tightly controlled uncertainty budgets are needed, like for qualification and calibration of instruments, or for method validation. And these are complemented by the aforementioned primary reference materials from national metrological institutes and the portfolio on matrix materials.

What do you see as the future developments in this area?

IH: Pesticide residue testing in food will become more and more important globally, partly because of the rising concerns about foodborne illnesses. This will lead to more stringent regulations in geographic areas other than the United States, Europe, Japan and China, where widely regulating legislations are already in place. As food manufacturers exporting food globally and to countries with different maximum residue limits (MRLs), they also have the individual MRLs in each target region to comply with the local regulations. Long term, this might lead to harmonization strategies between geographies regarding unified MRL values, as well as a harmonization regarding the approval of pesticides that are allowed to be used. We will continue to support analytical users in this context with the accurate and reliable reference materials they require.

Find out more about Merck's pesticide analysis solutions >>

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