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Foodborne Pesticide Analysis: Going Beyond the Dirty Dozen

Products for Pesticide Analysis

Identifying and measuring harmful pesticide residues

Pesticides are commonly used on the food we eat to control pests that may damage the crops during production, storage or transport. They also allow growers to increase the amount of usable food from each crop at the time of harvest, which may improve the quality, safety, and shelf-life of certain foods. For consumers, this means access to a wide variety of affordable foods, grown locally or imported from other states or countries.

However, some amount of those pesticides or their metabolites remain in or on the food – the pesticide residues.

To ensure the safety of consumers globally, each country has established maximum pesticide residue limits that can remain in or on a particular foodstuff. These limits commonly referred to as a pesticide tolerance or maximum residual level (MRL), are based on good agricultural practices and the lowest consumer exposures acceptably known to be nontoxic. To establish these levels national authorities like the U.S. Environmental Protection Agency (EPA) and the European Food Safety Authority (EFSA) evaluate the potential health risks of the pesticide. Before a pesticide can be used on a food crop, a risk assessment is performed by national authorities to determine whether and at what level a pesticide can be used without posing an unreasonable risk to human health.

Food monitoring in the U.S.

Under the Food Quality Protection Act (FQPA), the Environmental Protection Agency (EPA) must ensure that all pesticides used on food crops in the United States meet FQPA's stringent safety standards on both domestic and imported food commodities. Since the FQPA in 1996 the EPA has reevaluated 9,721 pesticide tolerances and revoked or modified almost 4,000 pesticide tolerances in a 10-year time frame.

Uses of a pesticide on food, whether a new application or new chemical, must be registered in order to be approved for use in the U.S United States. Prior to registration the EPA reviews each registration request for potential public health and environmental safety risks by evaluating against hundreds of scientific studies. Once a registration of a pesticide is approved for use on food the EPA reevaluates the safety of its use at a minimum of every 15 years by reviewing against any new scientific data and studies.

The Food and Drug Administration (FDA) then is one of the governing bodies who monitors and enforces pesticide tolerances legally allowed on or in food, including raw agricultural commodities, animal feed and processed foods through the Code of Federal Regulations, Title 40, Part 180. In addition, the FDA conducts the Total Diet Study (TDS) where levels of pesticide residues in foods prepared for consumption are collected and data evaluated to represent the average consumption of pesticide residue in the U.S. diet. Further, the FDA Pesticide Residue Monitoring Program tests a range of imported and domestic commodities (over 7,000 samples in 2016) for approximately 700 pesticide residues using a multi-residue method in a single analysis and also uses selective residue methods for those of interest not covered in the multi-residue method.

Tolerances for meat, poultry and some egg products are monitored and enforced by the U.S. Department of Agriculture (USDA). The Pesticide Data Program (PDP) under the USDA Agricultural Marketing Service (AMS) is another pesticide residue monitoring program in the U.S. yielding a comprehensive pesticide residue database through robust sampling, testing and reporting protocols. The AMS/USDA also enforces strict Pesticide Record Keeping outlined in the 1990 Farm Bill where “all private applicators are required by law to keep record(s) of their federally restricted use pesticide (RUP) applications for a period of 2 years.” There are 9 required elements that must be recorded within 14 days of each RUP application including brand or product name, EPA registration number, total amount applied, full date, location or coordinates of application, commodity, crop, stored product or site, size of area treated, name of certified applicator with certification number.

The EPA, FDA and USDA’s meticulous efforts to increase the safety of public and environmental health in the U.S. have resulted in some of the safest food supplies in the world.

Food monitoring in the E.U.

A large body of EU legislation regulates the marketing and use of plant protection products/pesticides and their residues in food. Plant protection products cannot be placed on the market or used without prior authorization. A dual system is in place, under which the European Food Safety Authority (EFSA) evaluates active substances used in plant protection products and Member States evaluate and authorize the products at national level. Plant protection products are principally regulated by framework Regulation (EC) No 1107/2009.

All matters related to legal limits for pesticide residues in food and feed are covered by Regulation (EC) No 396/2005. This regulation also contains provisions on official controls of pesticide residues in food of plant and animal origin that may arise from their use in plant protection.

The maximum residue levels (MRL) are derived after a comprehensive assessment of the properties of the active substance and the intended use of the pesticide. These legal limits also apply to imported food. Before an MRL is set or amended – for example, because an applicant requests the authorization of a new plant protection product – EFSA assesses the residue behavior of the pesticide and possible consumer health risks from residues in food. Provided that EFSA’s risk assessment does not identify any unacceptable risks to consumers, EU-harmonized MRLs are set and the plant protection product can be authorized.

All EU Member States are obliged to carry out controls to ensure that food placed on the market is compliant with legal limits. The European monitoring programs comprise one of the most comprehensive food survey programs in the world, analyzing more than 75,000 food samples for over 600 different pesticides every year.

Food monitoring

Persistent organic pollutants (POPs) and international environmental conventions

Persistent organic pollutants (POPs) are very stable hydrophobic molecules which are a threat to human health and to the environment. They can bioaccumulate through the food chain and pose significant health risks such as cancer, birth defects, reproductive disorders, and dysfunctional nervous and immune systems in humans and wildlife.

Stockholm Convention

In 2001, the Stockholm Convention was organized under the guidance of the United Nations Environment Programme (UNEP) to eradicate the most dangerous of these chemicals. It entered into force in May 2004 and listed 12 of the most dangerous POPs (the so called “dirty dozen”) with follow-up lists in May 2009, April 2011, May 2013 and May 2015. Since 2004 the list of POPs has been continuously extended.

Rotterdam Convention

In 1989, a Prior Informed Consent (PIC) procedure from the UNEP and the Food and Agriculture Organization of the United Nations was introduced resulting in a joint convention text in March 1998 known as the Rotterdam convention for certain hazardous chemicals in international trade. This entered into force in February 2004; since then, several amendments have been made, the latest in May 2015 resulted in a list of 16 additional POPs hazardous chemicals (including pesticides, PCBs, PCTs, and other organic pollutants). Three more substances are currently being evaluated and are proposed for listing under the convention: Dicofol; Pentadecafluorooctanoic acid its salts and PFOA-related compounds; and Perfluorohexanoic acid its salts and PFHxS related compounds

Pesticide regulations

More than 1000 active ingredients are currently registered as pesticides worldwide. They are heavily regulated by both international (e.g., European regulation (EC) No. 1107/2009), and national regulatory bodies (e.g., the Environmental Protection Agency (EPA) in the USA, the Brazil Pesticide Law 9974, or the Pesticides Management Bill, 2008 in India).

Out of these regulations, quality test methods have been developed to control levels of pesticide residues in food and feed, drinking and wastewater, and soil. We offer a variety of multi-component solutions as certified reference materials (CRMs) for various EPA and EN (European Norm) methods.

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Monitoring banned pesticide residues in food, feed, or animals

Periodic reevaluations of pesticide usage and risk by regional organizations sometimes leads to phase out recommendations or immediate bans to limit human health exposure. Testing for such compounds is typically reactionary based on local detection as was the case with Fipronil in chicken eggs in 2017 and the ban on three neonicotinoids (clothianidin, imidacloprid, thiamethoxam) on all field crops deemed to be dangerous for the bee population in 2018. New emerging industries such as medicinal and recreational Cannabis are requiring more oversight on quality and pesticide testing.

For more information on these pesticide residue topics visit our website:

Testing for pesticides in food and the environment

Pesticide monitoring compliance requires complete dedication not only from the food producers but also the developers of the testing equipment and supplies. Utilize our reliable pesticide testing tools, standards, and long-standing regulatory expertise to accurately monitor soil, water and food quality in compliance with national and international regulations.

Pesticide sample preparation

Traditional sample preparation techniques for pesticide analysis for food had a number of limitations including the need for a large quantity of solvents that are costly and can contaminate the sample as well as being time consuming. Dispersive SPE, QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) was developed to be a simple, effective and affordable way to extract pesticide residues from a wide range of fruit and vegetable matrices and is a popular laboratory technique. The right SPE products and accessories are essential for precise extraction and cleanup to ensure reliable analyte recovery, and removal of matrix interferences.

Solid-phase microextraction (SPME) is a solvent-free extraction technique suitable for many environmental methods. As the market leader and key driver of this technique, we offer the most complete line of SPME fibers and accessories, to match your application, including new overcoated (OC) fibers for extraction from complex food samples, spaghetti sauce for example.

For the complete listing, please visit: SigmaAldrich.com/spme

 

Internal standards: Isotope labeled pesticides

Spike your sample with our isotopically-labeled (13C-, 15N- or D-labeled) pesticides for determination of material loss during workup. We are continuously adding new isotopically-labeled standards for pesticide and pesticide metabolite analysis to our already extensive portfolio of over 150 products.

Find your labelled pesticide standard

Separation techniques

Find the GC and LC columns you need from the accurate, precise, and consistent tools and solutions from Supelco® Analytical Products.

GC and HPLC pesticide and herbicide analysis application notes

Find your protocol, guidelines, technique tips, and reagents for lab / field sampling and GC and HPLC separation and analysis of many key pesticides and herbicides.

Need more guidance for the application, protocol, or specific reagents you need?

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Pesticide method calibration, ISO 17025 and ISO Guide 34

For ISO/IEC 17025 accredited labs, it is mandatory to show traceability of all results, therefore certified reference materials (CRMs) must be used for calibration.

Our ISO/IEC 17025 and ISO Guide 34 double accreditation - the highest achievable quality level for reference material producers - ensures the quality of your reference materials. Our neat CRMs are certified by quantitative NMR (qNMR) and are traceable to NIST SRM. The CRM solutions are produced gravimetrically using NIST traceable weights for balance calibration.

  • Supplied with a comprehensive certificate according to ISO Guide 35 with properly calculated uncertainties, taking into account homogeneity and stability data
  • Expiry date stated on the certificate of analysis (CoA)
  • Convenient packages, either vials or amber-glass ampules, for better stability
  • Use as calibration standards, internal standards, surrogate standards, spiking solutions or laboratory control samples
  • Available as neat material, single-component solutions, or multi-component mixtures

Pesticide analytical standards: neat and solutions

For your routine analytics, choose your pesticide analytical standard from our broad portfolio:

Pesticide metabolites

Pesticides, by their very design, are active compounds that may be subsequently metabolized by target insects or plants or may be degraded in the environment. Monitoring of key pesticide metabolites and other transformation and degradation products is important to ensure more accurate measurements.

Choose from our broad continuously expanding metabolite portfolio.

Matrix reference materials for pesticide quality assurance

Organic or inorganic compound matrix Certified Reference Materials (CRMs) are invaluable for the validation of your analytical methods. Their primary role is to calibrate the mass-transfer process, but also as:

  • Quality control tools to assure ongoing performance of test methods and the validity of associated test results
  • A benchmark for comparing measurements between different laboratories
  • We are offering a variety of soil matrices, spiked with various pesticides:
  • “Real world” matrices (non-fortified)
  • Natural matrices, in which selected analytes have been fortified to give analytical profiles that meet the needs of analysts.
  • Most Certified Reference Materials (CRMs) are method specific and all are supplied with certificates that show:
  • Measured value plus uncertainty
  • Expanded uncertainty confidence interval
  • A prediction value, in addition to the mean value and standard deviation from the mean

Matrix material standards

GC and HPLC pesticide and herbicide analysis application notes

Find your protocol, guidelines, technique tips, and reagents for GC and HPLC separation and analysis of many key pesticides and herbicides.

Proficiency Testing (PT) Programs

ISO 17025 accredited laboratories are required to take part in proficiency testing (PT) programs to demonstrate performance of individual laboratories for specific tests.

The RTC brand represents over 20 years of experience and expertise in providing environmental PT studies worldwide. We produce and distribute over 20000 high-quality samples per annum for more than 2500 participants in our schemes. Our quality and services allow you to work smarter, enabling us to live in a safer and healthier world.

Our environmental Proficiency Testing (PT) programs cover:

  • Water Pollution / Wastewater
  • Water Supply / Drinking Water
  • Solids / Soils Hazardous Waste
  • Air /Emissions
  • Microbiology
  • Country specific

Laboratories can choose to participate in our quarterly or semi-annual Proficiency Testing (PT) programs, or simply purchase PT samples (Proficiency Testing Schedule)

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Water Purification Systems

Milli-Q® Lab Water Solutions – Delivering quality to meet all your water purity needs

Purified water is a ubiquitous reagent in most chemical analyses performed in the lab. Purity-and consistency of purity-is of paramount importance when striving to deliver accurate and reliable results.

Because you need to focus on releasing accurate and reproducible results, we ensure you have the water at the quality you need. Our Milli-Q® portfolio offers a broad range of pure and ultrapure water systems for your pesticide analyses.

The extreme sensitivity of analytical techniques, such as UHPLC, LC-MS, LC-MS/MS and GC-MS, requires scientists to use specifically adapted and highly pure reagents. When trying to detect and measure pesticides, special care must be taken to use ultrapure water that is free of any contaminant that could interfere with the analyses.
Discover the Milli-Q® IQ 7003/05/10/15 integrated ultrapure and pure water system, designed to provide consistently high-quality purified water for your sensitive applications while improving your lab’s productivity and reducing its environmental impact:

  • A full range of Application-Pak polishers lets you tailor both pure and ultrapure water to your specific application needs.
  • The LC-Pak® polisher, containing reversed-phase C18 silica, purifies ultrapure water for your critical LC-MS analyses
  • The system delivers low TOC (Total Oxidizable Carbon) ultrapure water, accurately measured by our best-in-class online A10® monitor
  • A completely mercury-free system that can provide water and energy savings, reduced plastic waste and paperless data management
Read more about water purification solutions

Milli-Q® IQ 7003/05/10/15

Materials