Methodological developments in the sampling of foods and feeds for mycotoxin analysis (original) (raw)
Related papers
Sampling feed for mycotoxins: acquiring knowledge from food
Italian Journal of Animal Science, 2009
The occurrence and control of mycotoxins in feed and food are items of great interest to researchers, producers, manufacturers and regulatory agencies. In order to implement knowledge of control measures for mycotoxins in the entire food production chain, coordinated inspection programmes aimed to check the presence and concentration of mycotoxins in feedingstuffs are recommended by the Commission of the European Communities. Reliability of measured levels of mycotoxins in feed and food is greatly affected by the collection of representative samples. Because of the heterogeneous distribution of mycotoxins, the variability associated with a mycotoxin test procedure usually depends heavily on the sampling plan. European legislation dealing with sampling plans for mycotoxins in foodstuffs has been recently revised. The aim of the following overview is to discuss the role of sampling in mycotoxin-contaminated feed by considering the evolution of legislation dealing with sampling plans for food. A sampling procedure is a multistage process and consists of three distinct phases: sampling, sample preparation and analysis. The variability associated with each step of a sampling procedure and the aspects related to feedstuffs, matrix/mycotoxin combination and level of contamination are discussed.
The role of sampling in mycotoxin contamination: An holistic view
Food Additives & Contaminants, 2005
The need of obtaining a representative sample deserves particular consideration since a wrong sampling plan can greatly affect the reliability of the measured levels of mycotoxins. This can even result in legal disputes and barriers to trade. Reported here is a holistic view for an ideal sampling plan, which is based on two consecutive steps: 1) to establish "why, where and when" sampling has to be performed by assessing the purpose, the appropriate time and the site for collecting the samples; 2) to establish "how" to draw samples by assessing practical ad hoc guidelines, considering that, for bulk goods in particular, mycotoxins are not at all homogeneously distributed in a lot. So far, step 1 is not yet covered by specific guidelines while for step 2, European regulations establish the procedures for the sampling of bulk and retail products potentially contaminated by mycotoxins.
Validation of analytical methods for determining mycotoxins in foodstuffs
TrAC Trends in Analytical Chemistry, 2002
The European Union (EU) has established demanding regulatory limits for controlling aflatoxins B 1 , B 2 , G 1 and G 2 , in cereals, nuts, nut products and dried fruit, aflatoxin M 1 in milk, and ochratoxin A in cereals. These limits are likely to be extended in the future to additional commodities and other mycotoxins. For enforcement purposes and in particular for resolving any disputes between parties, it is essential that validated methods are available, with performance characteristics that meet certain minimum criteria. As such methods were not available and had not previously been validated either for matrices of interest in Europe or at the low European limits compared to the USA, the EU funded a method-validation project to fulfil this requirement. Immunoaffinity column clean-up methods with HPLC determination were established for aflatoxins B 1 , B 2 , G 1 and G 2 in peanut butter, pistachios, fig paste and paprika, aflatoxin B 1 in baby food, aflatoxin M 1 in liquid milk, and ochratoxin A in roasted coffee and baby food. For patulin in apple juice and apple puree, solvent extraction and solid-phase clean-up HPLC methods were developed. To undertake collaborative studies, particular care was taken in preparation of naturally-contaminated test materials containing the toxins at levels close to regulatory limits and in demonstrating the homogeneity of batches of material. To ensure that participants in the validation exercise could follow the procedures to be tested, videos of the methods were prepared showing, in particular, any critical steps. Prior to undertaking the method validation, participants were invited to collaborative study workshops to ensure that they fully understood the methods and their role in the study. This care in planning and executing the collaborative studies led to impressive performance characteristics and adoption of six procedures by AOAC International as First Action Methods and seven methods by CEN as European standards. The valuable lessons learned in undertaking these validation exercises are now being put to further use in studies aimed at validating methods for mycotoxins in foodstuffs, which are appropriate for developing countries based on TLC as the end determination but use more modern sample cleanup techniques. #
2009
Abstract: Mycotoxins are a group of compounds produced by various fungi and excreted into the matrices on which they grow, often food intended for human consumption or animal feed. The high toxicity and carcinogenicity of these compounds and their ability to cause various pathological conditions has led to widespread screening of foods and feeds potentially polluted with them. Maximum permissible levels in different matrices have also been established for some toxins. As these are quite low, analytical methods for determination of mycotoxins have to be both sensitive and specific. In addition, an appropriate sample preparation and pre-concentration method is needed to isolate analytes from rather complicated samples. In this article, an overview of methods for analysis and sample preparation published in the last ten years is given for the most often encountered mycotoxins in different samples, mainly in food. Special emphasis is on liquid chromatography with fluorescence and mass s...
Qualitative and Quantitative Analysis of Mycotoxins
Comprehensive Reviews in Food Science and Food Safety, 2009
Mycotoxin toxicity occurs at very low concentrations, therefore sensitive and reliable methods for their detection are required. Consequently, sampling and analysis of mycotoxins is of critical importance because failure to achieve a suitable verified analysis can lead to unacceptable consignments being accepted or satisfactory shipments unnecessarily rejected. The general mycotoxin analyses carried out in laboratories are still based on physicochemical methods, which are continually improved. Further research in mycotoxin analysis has been established in such techniques as screening methods with TLC, GC, HPLC, and LC-MS. In some areas of mycotoxin method development, immunoaffinity columns and multifunctional columns are good choices as cleanup methods. They are appropriate to displace conventional liquid-liquid partitioning or column chromatography cleanup. On the other hand, the need for rapid yes/no decisions for exported or imported products has led to a number of new screening methods, mainly, rapid and easy-to-use test kits based on immuno-analytical principles. In view of the fact that analytical methods for detecting mycotoxins have become more prevalent, sensitive, and specific, surveillance of foods for mycotoxin contamination has become more commonplace. Reliability of methods and well-defined performance characteristics are essential for method validation. This article covers some of the latest activities and progress in qualitative and quantitative mycotoxin analysis.
Towards harmonized approaches for mycotoxin analyses: an assessment
Quality Assurance and Safety of Crops & Foods, 2009
Mycotoxins (the poisonous metabolites of certain filamentous fungi) are potential contaminants of staple food commodities and, if uncontrolled, may present a significant public health hazard. In many jurisdictions, questions relating to mycotoxin contamination are addressed at both generic and specific levels by food-safety legislation. Key to the successful management of the mycotoxin question, both in terms of verifying food-safety measures by the agri-food businesses and ensuring compliance with statutory limits by enforcement agencies, is the use of reliable sampling and analytical methodology. Evidence from European Union Rapid Alert System for Food and Feed data suggest that harmonization of methodologies used to determine the mycotoxin content of foods would contribute to improved compliance at both regulatory and commercial levels.
An Overview of Conventional and Emerging Analytical Methods for the Determination of Mycotoxins
International Journal of Molecular Sciences, 2009
Mycotoxins are a group of compounds produced by various fungi and excreted into the matrices on which they grow, often food intended for human consumption or animal feed. The high toxicity and carcinogenicity of these compounds and their ability to cause various pathological conditions has led to widespread screening of foods and feeds potentially polluted with them. Maximum permissible levels in different matrices have also been established for some toxins. As these are quite low, analytical methods for determination of mycotoxins have to be both sensitive and specific. In addition, an appropriate sample preparation and pre-concentration method is needed to isolate analytes from rather complicated samples. In this article, an overview of methods for analysis and sample preparation published in the last ten years is given for the most often encountered mycotoxins in different samples, mainly in food. Special emphasis is on liquid chromatography with fluorescence and mass spectrometric detection, while in the field of sample preparation various solid-phase extraction approaches are discussed. However, an overview of other analytical and sample preparation methods less often used is also given. Finally, different matrices where mycotoxins have to be determined are discussed with the emphasis on their specific characteristics important for the analysis (human food and beverages, animal feed, biological samples, environmental samples). Various issues important for accurate qualitative and quantitative analyses are critically discussed: sampling and choice of representative sample, sample preparation and possible bias associated with it, specificity of the analytical method and critical evaluation of results.
Rapid Communications in Mass Spectrometry, 2012
RATIONALE: Mycotoxins are typically present in grain and are also concentrated in distillers dried grains with solubles (DDGS), common feed ingredients for food animals. The diversity of mycotoxins and feed matrices has made the routine detection and quantification of mycotoxins in feed both complex and prohibitively expensive. METHODS: Ultra-performance liquid chromatography/electrospray ionization triple quadrupole detection (UPLC/ESI-TQD) (tandem mass spectrometry, MS/MS) with 13 C-labeled isotopic dilution was used to analyze internal standard isotopologues of three mycotoxin molecules, as well as 29 other structurally differing mycotoxin molecules from four common feed matrices: corn, wheat, barley, or DDGS. Mycotoxins were extracted via a single-step procedure using a mixture of acetonitrile/water/formic acid. Labeled isotopologues were used as a surrogate to account for extraction quality and as internal standards for the evaluation of the feed matrix signal suppression/enhancement (SSE) contributed by each mycotoxin and by each matrix. The SSE was corrected by matrix-matched calibration with blank certified reference feed material. RESULTS: The limits of detection for individual mycotoxins in buffer ranged from 0.01 to 206.7 mg/mL but could increase by up to four times depending on the matrix effect. The accuracy and precision were enhanced by the use of isotopically labeled standards. The recoveries were somewhat negatively affected by the SSE contributed by each matrix. Each mycotoxin was successfully detected and assigned to one of four SSE categories: high (-66%), intermediate (-48%), low (-19%) signal suppression and signal enhancement (> +300%). CONCLUSIONS: An improved LC/MS method was validated, which offers a practical and economical means for large-scale detection and quantification of multiple mycotoxins in common animal-feed matrices, including DDGS.