Deoxynivalenol (DON), commonly known as vomitoxin, is one of the most frequently detected trichothecene mycotoxins in cereals and cereal-based products worldwide, making accurate determination essential for food safety, regulatory compliance, and international trade. This technical guide explains the chemistry and toxicology of vomitoxin, applicable regulatory limits, representative sample matrices, and validated analytical methods — including immunoaffinity cleanup HPLC, LC-MS/MS, ELISA, and rapid lateral flow screening — as routinely performed by accredited third-party laboratories.
Technical Overview
Deoxynivalenol (DON), widely referred to as vomitoxin, is a type B trichothecene mycotoxin (molecular formula C15H20O6, molecular weight 296.32 g/mol) produced primarily by the plant-pathogenic fungi Fusarium graminearum and Fusarium culmorum. These fungi cause Fusarium head blight in wheat and gibberella ear rot in maize, and infection occurs mainly in the field under warm, humid flowering conditions. Poor drying and storage can further increase toxin levels.
DON is a potent inhibitor of eukaryotic protein synthesis. Acute exposure in humans causes nausea, vomiting, abdominal pain, and diarrhea — the symptoms that gave the toxin its common name — while chronic exposure is associated with reduced weight gain, anorexia, immunomodulation, and impaired intestinal function. In livestock, especially swine, DON is notorious for triggering feed refusal and vomiting. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA) have each established a group tolerable daily intake of 1 µg/kg body weight per day covering DON, its acetylated derivatives, and DON-3-glucoside. The International Agency for Research on Cancer (IARC) classifies DON as Group 3 (not classifiable as to its carcinogenicity).
DON is chemically stable, highly polar, and heat resistant, so it largely survives milling, baking, extrusion, and other thermal processing. It frequently concentrates in milling fractions such as bran and germ and in fermentation co-products such as DDGS. Regulatory and advisory limits in major markets include:
- European Union (Regulation (EU) No 2023/915): 1,750 µg/kg for unprocessed durum wheat, oats, and maize; 1,250 µg/kg for unprocessed common wheat and barley; 750 µg/kg for cereal flour and pasta; 500 µg/kg for bread, biscuits, breakfast cereals, and cereal snacks; 200 µg/kg for processed cereal-based foods for infants and young children.
- United States (FDA advisory levels and compliance policy guidance): 1 ppm (1,000 µg/kg) in finished wheat products for human consumption, and 5–10 ppm for grain and grain by-products destined for animal feed, subject to species-specific limits on dietary inclusion rates.
- China (GB 2761 national food safety standard for mycotoxin limits): 1,000 µg/kg for wheat, maize, and their milled products.
- Codex Alimentarius: international reference maximum levels for DON in raw cereals and cereal products used as the benchmark in international trade.
Testing Samples
Raw Cereals and Grains
Wheat, durum wheat, barley, oats, rye, triticale, and maize represent the highest-risk matrices. Testing is typically performed at harvest intake, during silo storage, and prior to sale or export. Because Fusarium contamination is highly heterogeneous, representative sampling is decisive for a meaningful result.
Milled and Intermediate Cereal Products
Wheat flour, semolina, bran, wheat germ, maize meal, gluten, and starch are tested to verify compliance with stricter processed-product limits and to document mass-balance behavior across the milling stream, where DON typically partitions toward the outer kernel fractions.
Finished Foods
Bread, pasta, breakfast cereals, biscuits, cereal-based snacks, and processed cereal-based baby foods are tested, since these categories carry the lowest legal limits and are consumed by sensitive populations including infants and children.
Malting and Brewing Materials
Malting barley, malt, wort, and finished beer are analyzed because DON is water soluble and can transfer into brewing liquor and the final beverage, while its derivatives may be modified during fermentation.
Animal Feed and Feed Ingredients
Cereal raw materials, compound feeds, corn gluten meal, and DDGS are monitored against feed advisory or statutory limits. Fermentation co-products such as DDGS can exhibit DON concentrations approximately three times higher than the starting grain.
Forage and Silage
Maize silage, hay, and total mixed rations are screened to support livestock health management, particularly for dairy and swine operations sensitive to trichothecene contamination.
Testing Items
Typical determination items and reporting parameters include:
- Deoxynivalenol (vomitoxin) content, reported in µg/kg (ppb) on a product-weight basis.
- 3-acetyl-DON and 15-acetyl-DON, the acetylated derivatives that contribute to the group tolerable daily intake.
- DON-3-glucoside, a masked mycotoxin formed by plant metabolism and hydrolyzed back to DON in the digestive tract.
- Total DON equivalents, summing the parent toxin and relevant derivatives where required by risk assessment.
- Regulatory compliance assessment against the limit applicable to the destination market and product category.
Typical limits of quantification are approximately 20–100 µg/kg for HPLC-UV procedures and below 5–10 µg/kg for LC-MS/MS, comfortably below the strictest baby-food limits of 200 µg/kg.
Testing Methods
Sampling and Sample Preparation
Correct sampling is the largest source of analytical uncertainty. In line with European sampling rules for mycotoxins (Commission Regulation (EC) No 401/2006), at least 10 incremental portions are drawn from a lot and combined into an aggregate sample, which is ground and homogenized before a laboratory test portion (commonly 25 g) is extracted. Because DON is highly polar, extraction is performed with water or acetonitrile–water mixtures (typically 84:16, v/v). Extracts are filtered and, for chromatographic methods, cleaned up through DON-specific immunoaffinity columns that retain the toxin while removing matrix interferences.
Immunoaffinity Cleanup with HPLC-UV/DAD
This is the established reference procedure described in EN 15891 and in the Chinese national food safety standard GB 5009.111. Following immunoaffinity purification and methanol elution, DON is separated on a reversed-phase C18 column with a water–methanol or water–acetonitrile mobile phase and quantified by UV or diode-array detection at approximately 218–220 nm. The method offers robust quantification from roughly 50–100 µg/kg upward, fully validated through collaborative trials.
Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS)
LC-MS/MS with electrospray ionization in negative mode and multiple-reaction-monitoring transitions is the most sensitive and versatile approach. It permits simultaneous determination of DON, 3-acetyl-DON, 15-acetyl-DON, DON-3-glucoside, and other trichothecenes in a single run, and it accommodates dilute-and-shoot or cleaned-up workflows. Quantification with isotopically labelled internal standards, such as carbon-13 labelled DON, compensates for matrix effects and delivers the lowest achievable measurement uncertainty.
ELISA Screening
Competitive enzyme-linked immunosorbent assays in 96-well format enable high-throughput screening of large sample numbers with detection thresholds typically in the range of 50–150 µg/kg. ELISA is cost-effective for surveillance and intake control, but positive or legally significant results should be confirmed by a validated chromatographic method.
Lateral Flow Immunochromatography
Rapid test strips provide on-site, semi-quantitative results within 5–10 minutes using portable readers. They are widely used at grain intake, in truckside testing, and within HACCP programs as an early-warning tool, again followed by confirmatory laboratory analysis where required.
Gas Chromatographic Methods (Historical)
Earlier procedures based on trimethylsilyl derivatization followed by GC-ECD or GC-MS detection were formally validated but have largely been superseded by liquid-chromatographic techniques offering simpler sample handling and better selectivity.
Quality Control and Method Validation
Accredited third-party laboratories operating under ISO/IEC 17025 validate DON methods with matrix-matched or isotope-dilution calibration, certified reference materials, spike recovery studies (typically 70–110%), repeatability relative standard deviations below 20%, and regular participation in interlaboratory proficiency testing schemes. Performance criteria for accepted analytical methods, including recovery and precision requirements as a function of concentration, are specified in European mycotoxin legislation and mirrored in national standards such as GB 5009.111 and the Chinese feed standard GB/T 23503.
Applications
- Grain trade and procurement: lot acceptance testing, contract specification verification, and export certification for wheat, barley, maize, and other cereals.
- Flour milling and food manufacturing: process control across milling streams, ingredient release, and finished-product compliance for bread, pasta, cereals, and snacks.
- Brewing and malting: barley and malt intake screening plus wort and beer verification to protect beverage quality.
- Animal nutrition: feed ingredient evaluation, diet formulation for swine and poultry, and monitoring of high-risk co-products such as DDGS.
- Regulatory surveillance: official control programs, import inspection, and border rejection assessments.
- Research and breeding: screening germplasm for Fusarium head blight resistance, studying toxin fate during processing, and evaluating storage mitigation strategies.
- HACCP and mycotoxin management: monitoring critical control points from field to fork and providing documentary evidence for audits and customer due diligence.
FAQ
Why is deoxynivalenol called vomitoxin?
The name arose from the characteristic acute symptoms it causes — vomiting, nausea, and diarrhea — in humans and animals, notably swine, after consumption of contaminated grain.
Which products are most often affected?
Wheat and maize are the leading contributors to dietary exposure, followed by barley, oats, and rye. Wheat bran, germ, and maize DDGS frequently show the highest concentrations within a processing chain.
How much sample is required for a valid test?
A representative aggregate sample of approximately 0.5–1 kg, assembled from at least 10 incremental portions taken across the lot, is ground and homogenized; analytical test portions are typically 25 g. Submitting only a small handful of grain is the most common cause of misleading results.
Does cooking destroy DON?
No. DON is thermally stable, and while baking or extrusion can cause minor reductions or redistribution, significant toxin typically persists into the finished food, which is why finished-product testing remains necessary.
What is the difference between screening and confirmatory testing?
Lateral flow and ELISA tests are rapid screening tools that indicate whether contamination is present near a threshold. HPLC and LC-MS/MS methods are confirmatory techniques that deliver legally defensible quantitative results.
How long does determination take?
Rapid strip tests provide results in under 15 minutes. Confirmatory HPLC or LC-MS/MS analysis at an accredited laboratory is typically completed within 3–7 working days after sample receipt, including extraction, cleanup, instrumental analysis, and reporting.
Which standard applies to my product?
The applicable limit depends on the product category and destination market — for example, EN 15891 and GB 5009.111 govern chromatographic determination, while maximum levels are set by EU Regulation 2023/915, GB 2761, FDA advisory levels, or Codex reference levels. Selecting the correct combination of method and limit is a key part of the testing plan.