The Netherlands Food and Consumer Product Safety Authority NVWA closed down an animal feed company that generated €4 million revenue selling contaminated feed with forged documents. Several thousand tons of waste, unsuitable to use in animal feed, was found at the facility, and three employees have been arrested.
Dioxins are highly toxic organic compounds that can remain in the environment for extended periods. These persistent organic pollutants (POPs), which include polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), are mainly generated by the combustion or manufacture of chlorine-containing materials such as plastics. Dioxins and other closely related POPs, such as polychlorinated biphenyls (PCBs), are classed as carcinogenic by the United States Environmental Protection Agency, and present a significant threat to human health even at low levels.
Dioxins and PCBs can enter the food chain when livestock consume contaminated animal feed, and can accumulate in the fatty tissues of animals due to their high fat-solubility. As a result, over 90% of human exposure to dioxins and PCBs is through the consumption of meat, fish, dairy and other foods of animal origin.1 Given the health risks posed by dioxins and PCBs, effective food testing workflows are essential to ensure products do not exceed regulatory-defined safe levels.
GC-MS/MS: A Robust Technique for Analyzing Dioxins and PCBs in Food and Animal Feed
To control human exposure to PCDDs, PCDFs and PCBs from the food chain, global regulatory bodies have established maximum levels (MLs) and action levels (ALs) for various POPs in food products, as well as approved analytical methods for food testing laboratories to enforce these standards. In the European Union (EU), for example, European Commission regulations 2017/644 and 2017/771 outline sampling, sample preparation and analysis protocols for the detection of dioxins and other dioxin-like compounds in food and animal feedstuffs.2,3
With food testing laboratories tasked with handling potentially hundreds of samples every day, these workflows must be supported by robust and reliable analytical technologies that can confidently identify and accurately quantify dioxins and PCBs with minimal maintenance requirements in order to minimize downtime and maximize throughput.
Thanks to ongoing improvements in the robustness and sensitivity of gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) systems, regulations were updated in 2014 to permit this technique as an alternative to gas chromatography-high resolution mass spectrometry (GC-HRMS) for confirmatory analysis and for the control of MLs and ALs. The latest GC-MS/MS systems are capable of exceptionally reliable performance for the routine analysis of dioxins and PCBs, providing accurate and sensitive quantification of these compounds even at trace levels.
Case Study: Sensitive and Reliable Determination of Dioxins Using GC-MS/MS
The performance of modern GC-MS/MS systems was evaluated in a recent study involving the confirmatory analysis and quantification of 17 PCDDs and PCDFs, and 18 dioxin-like and non-dioxin-like PCBs in solvent standards and various food and feedstuff samples. The samples were analyzed using a triple quadrupole GC-MS/MS system equipped with the advanced electron ionization source (AEI) and a TG-Dioxin capillary GC column. Two identical GC-MS/MS systems in two separate laboratories were used to assess the reproducibility of the method.
Extraction was performed by Twisselmann hot extraction or pressurized liquid extraction. The automated clean-up of the extracts was performed using a three-column setup, comprising multi-layered acidic silica, alumina and carbon columns. Two fractions were generated per sample (the first containing non-ortho PCBs, PCDDs and PCDFs, and the second containing mono-ortho and di-ortho PCBs and indicator PCBs) and these were analyzed separately. The analytical method gave excellent separation of all the PCDD, PCDF and PCB congeners in less than 45 minutes.
Given the high sensitivity of modern GC-MS/MS instruments, a calibration-based approach was used to determine limits of quantitation (LOQs) of the analytical system. Using calibration standards at the LOQ and subsequent check standards at this level enabled the performance of the method to be assessed throughout the analytical sequence. This also allowed LOQs for the individual congeners to be determined, assuming a fixed sample weight. Individual congener LOQs could be applied to upper-bound, middle-bound and lower-bound toxicity equivalence (TEQ) results by substituting the result of any congener that fell below the lowest calibration point with this value multiplied by the toxicity equivalence factor (TEF) of the congener.
To evaluate the response factor deviation over the course of the analytical sequences, standards at the specified LOQ were analyzed at the start, during and end of each run. Using a nominal weight of 2 g, and assuming 100% 13C-labeled standard recovery and all natives were less than the LOQ in the sample, a minimum upper-bound value of 0.152 pg/g WHO-PCDD/F-TEQ was determined. This met regulatory requirements for reporting at 1/5th of the ML upper-bound sum TEQ for all food and feedstuffs with a nominal intake of 2 g, with the exception of guidance associated with liver of terrestrial animals and food for infants or young children, which both have legal limits defined on a fresh weight basis. In these cases, either a larger sample intake or a magnetic sector instrument would be required. All of the calibration sequences demonstrated response factor %RSDs within EU regulations, highlighting the suitability of the method.
To demonstrate the performance of the GC-MS/MS system, six replicate extractions of a mixed fat quality control sample (QK1) were prepared, split between the two sites and analyzed at regular intervals throughout the analytical sequences (14 injections in total). The measured WHO-PCDD/F-TEQ values for congener were in excellent agreement with the reference value provided by the EU Reference Laboratory for Halogenated POPs in Feed and Food, and the upper bound WHO-PCDD/F-TEQ value did not deviate by more than 6% from the reference value for all 14 measurements (Figure 1). The deviation between the upper-bound and lower-bound WHO-PCDD/F-TEQ for each measurement was consistently less than 1.2%, well below the maximum limit of 20% necessary to support compliance with EU regulations.
Robust Routine Analysis of Dioxin and Dioxin-like Compounds
To assess the robustness of the GC-MS/MS system, the PCDD, PCDF and non-ortho PCB extracts were pooled into a mixed matrix sample and analyzed more than 161 injection sequences across a period of approximately two weeks. Each sequence consisted of 40 matrix injections and 40 LOQ standards, interspersed with nonane blanks. No system maintenance, tuning or user intervention was undertaken throughout the two-week study. Figure 2 highlights the exceptional peak area stability achieved for selected PCDD and PCDF congeners.
These results highlight the exceptional levels of day-to-day measurement repeatability offered by the latest GC-MS/MS systems. By delivering consistently high performance without the need for extensive maintenance steps, modern GC-MS/MS systems are maximizing instrument uptime and increasing sample throughput for routine POP analysis workflows.
Developments in GC-MS/MS technology, namely the advanced electron ionization source, are pushing the limits of measurement sensitivity, repeatability and robustness to support the needs of routine dioxin and PCBs analysis in food and feed samples. By minimizing instrument downtime while maintaining exceptional levels of analytical performance, these advanced systems are helping high-throughput food testing laboratories to analyze more samples and ultimately better protect consumers from these harmful pollutants.
Malisch, R. and Kotz, A. (2014) Dioxins and PCBs in feed and food – Review from European perspective. Sci Total Environ, 491, 2-10.
European Commission. Commission Regulation (EU) 2017/644, Off J Eur Union, 2017, L92 9-34.
European Commission. Commission Regulation (EU) 2017/771, Off J Eur Union, 2017, L115 22-42.
This article is based on research by Richard Law and Cristian Cojocariu (Thermo Fisher Scientific, Runcorn, UK), Alexander Schaechtele (EU Reference Laboratory for Halogenated POPs in Feed and Food, Freiburg, Germany), Amit Gujar (Thermo Fisher Scientific, Austin, US), and Jiangtao Xing (Thermo Fisher Scientific, Beijing, China).
Covered facilities must establish and implement a food safety system with a written food safety plan that includes hazard analysis, preventive controls, and the oversight and management of preventive controls (this encompasses monitoring, corrective actions and verification).
The “farm” definition has been clarified to include two types of farm operations, primary production farm and secondary activities farm. Such farms that conduct produce activities will also have to comply with the Produce Safety Rule (to be finalized at the end of October).
A more flexible supply chain program, with separate compliance dates.
Update and clarification to CGMPs.
This year’s Food Safety Consortium conference will feature first-hand perspectives from FDA and USDA on FSMA implementation and enforcement. REGISTER NOWCompliance dates range between one and three years depending on the size and type of business. Several guidance documents will be created by FDA in an effort to further help companies with compliance, including on hazard analysis and preventive controls, environmental monitoring, food allergen controls, and the validation of process controls.
The Federal Register will publish the 930-page document on September 17. In the meantime, the pre-publication version can be viewed here.
CGMPs established for the production of animal food, taking into account the diverse types of animal food facilities.
Covered facilities must establish and implement a food safety system with a written food safety plan that includes hazard analysis, preventive controls, the oversight and management of preventive controls (this encompasses monitoring, corrective actions and verification), and a recall plan.
A more flexible supply chain program, with separate compliance dates.
The “farm” definition has been clarified to include two types of farm operations, primary production farm and secondary activities farm.
Feed mills associated with farms (vertically integrated operations) are not covered.
As with the preventive controls for human food, FDA will be creating guidance documents that address CGMP requirements, hazard analysis and preventive controls, human food by-products for use as animal food, and a small-entity compliance guide.
The Federal Register will also publish this 666-page document on September 17. The pre-publication version can be viewed here.
At this year’s Food Safety Consortium Conference, the industry will have the opportunity to hear directly from FDA and USDA on what companies need to know to be FSMA compliant and how the agency will be enforcing the regulation. Michael Taylor, JD, deputy commissioner for foods and veterinary medicine at FDA, will delivery the opening plenary presentation, which will be followed by an “Ask the FDA” Q&A town hall meeting.
According to an FDA alert, the agency has submitted the final preventive controls rules for human and animal food to the Federal Register. FDA notes it can take several days from the date of submission to final publication.
“The FDA is committed to sharing information about the final rules and how food facilities can comply as soon as we are able to do so.” The agency will be providing more information on the FSMA section of its website.
Strictly Necessary Cookies
Strictly Necessary Cookies should be enabled at all times so that we can save your preferences for these cookie settings.
We use tracking pixels that set your arrival time at our website, this is used as part of our anti-spam and security measures. Disabling this tracking pixel would disable some of our security measures, and is therefore considered necessary for the safe operation of the website. This tracking pixel is cleared from your system when you delete files in your history.
If you visit and/or use the FST Training Calendar, cookies are used to store your search terms, and keep track of which records you have seen already. Without these cookies, the Training Calendar would not work.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.
A browser cookie is a small piece of data that is stored on your device to help websites and mobile apps remember things about you. Other technologies, including Web storage and identifiers associated with your device, may be used for similar purposes. In this policy, we say “cookies” to discuss all of these technologies.
Data generated from cookies and other behavioral tracking technology is not made available to any outside parties, and is only used in the aggregate to make editorial decisions for the websites. Most browsers are initially set up to accept cookies, but you can reset your browser to refuse all cookies or to indicate when a cookie is being sent by visiting this Cookies Policy page. If your cookies are disabled in the browser, neither the tracking cookie nor the preference cookie is set, and you are in effect opted-out.
In other cases, our advertisers request to use third-party tracking to verify our ad delivery, or to remarket their products and/or services to you on other websites. You may opt-out of these tracking pixels by adjusting the Do Not Track settings in your browser, or by visiting the Network Advertising Initiative Opt Out page.
You have control over whether, how, and when cookies and other tracking technologies are installed on your devices. Although each browser is different, most browsers enable their users to access and edit their cookie preferences in their browser settings. The rejection or disabling of some cookies may impact certain features of the site or to cause some of the website’s services not to function properly.
The use of online tracking mechanisms by third parties is subject to those third parties’ own privacy policies, and not this Policy. If you prefer to prevent third parties from setting and accessing cookies on your computer, you may set your browser to block all cookies. Additionally, you may remove yourself from the targeted advertising of companies within the Network Advertising Initiative by opting out here, or of companies participating in the Digital Advertising Alliance program by opting out here.