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Fusarium mycotoxins are common contaminants in cereals and often co-occur with plant-derived mycotoxin sugar conjugates. Several of these modified mycotoxins are not degraded in the small intestine and hence carried through to the large intestine where microbial transformation may occur. This study aims to assess the gastrointestinal stability of the trichothecenes HT-2 toxin (HT-2), HT-2-β-glucoside (HT-2-Glc), diacetoxyscirpenol (DAS), DAS-α-glucoside (DAS-Glc) and fumonisin B1 (FB1), N-(1-deoxy-d-fructos-1-yl) fumonisin-B1 (NDF-FB1). All tested modified mycotoxins were stable under upper gastrointestinal (GI) conditions. In faecal batch culture experiments, HT-2-Glc was hydrolysed efficiently and no further microbial biotransformation of HT-2 was observed. DAS-Glc hydrolysis was slow and DAS was de-acetylated to 15-monoacetoxyscripenol. NDF-FB1 was hydrolysed at the slowest rate and FB1 accumulation varied between donor samples. Our results demonstrate that all tested modified mycotoxins are stable in the upper GI tract and efficiently hydrolysed by human gut microbiota, thus potentially contributing to colonic toxicity. Hence the microbial biotransformation of any novel modified mycotoxins needs to be carefully evaluated.

To assess the in vitro activity of three phenolic acids (ferulic acid, p-hydroxybenzoic acid, vanillic acid) and two flavonols (quercetin, rutin) on mycelial growth and mycotoxin accumulation of Fusarium graminearum (FG), F. langsethiae (FL) and F. poae (FP), two different approaches were chosen. First, grains from oat varieties were inoculated with a suspension of three FL isolates to determine the influence of phenolic compounds on the accumulation of mycotoxins. The oat variety Zorro showed a tendency for lower accumulation of T-2/HT-2, diacetoxyscirpenol and neosolaniol. Second, a mycelium growth assay was conducted to follow FG, FL and FP growth on cereal based media supplemented with phenolic compounds. Increasing concentrations of ferulic acid substantially inhibited growth of FG and FL, while FP growth was reduced to 57%. In contrast, p-hydroxybenzoic acid, vanillic acid, quercetin, and rutin slightly stimulated mycelium growth. Results about mycotoxin production in cereal based media were less conclusive.

A method for the determination of seven trichothecenes, neosolaniol (NEO), diacetoxyscirpenol (DAS), deoxynivalenol (DON), nivalenol (NIV), fusarenon-X (FUS-X), 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON), in laboratory rat feed by GC-MS/MS was developed. Sample extraction and purification was performed by an acidified mixture of acetonitrile/water (80-20% v/v). Limits of quantitation (LOQs) were between 1 and 10 μg kg(-1) for all studied trichothecenes. Eight concentration levels between the LOQ and 100 × LOQ were used for the calibration curves. Matrix-matched calibration was used for quantitation purposes to compensate the detector signal enhancement obtained for all the analytes. The method accuracy was evaluated by recovery assays at three concentration levels, 25, 50 and 100 μg kg(-1) (n = 9). Recoveries ranged from 62% to 97% and precision, expressed as intra- and inter-day relative standard deviations, was evaluated for all compounds. The validated method was successfully applied to the analysis of 35 laboratory rat feed samples showing mycotoxin contamination in 66% of the samples. DON was the most prevalent trichothecene followed by 15-ADON, NIV and 3-ADON. The maximum DON concentration reached in real samples was 2156 ± 4.3 μg kg(-1), while NEO, DAS and FUS-X were not detected in any sample. Multi-contamination by at least two mycotoxins was observed in 17% of the analysed feed samples.

This paper reports a new method for the determination of T-2 and HT-2 toxins and their glucosylated derivatives in cereals, and some survey data aimed at obtaining more comprehensive information on the co-occurrence of T-2 and HT-2 toxins and their glucosylated derivatives in naturally contaminated cereal samples. For these purposes, barley samples originating from a Northern Italian area were analysed by LC-HRMS for the presence of T-2, HT-2 and relevant glucosyl derivatives. Quantitative analysis of T-2 and HT-2 glucosides was performed for the first time using a recently made available standard of T-2 glucoside. The glucosyl derivative of HT-2 was detected at levels up to 163 mu gkg(-1) in 17 of the 18 analysed unprocessed barley grains, whereas the monoglucosyl derivative of T-2 toxin was detected in only a few samples and at low mu gkg(-1) levels. The ratio between glucosylated toxins (sum of T-2 and HT-2 glucosides) and native toxins (sum of T-2 and HT-2) ranged from 2% to 283%. Moreover, taking advantage of the possibility of retrospective analysis of full-scan HRMS chromatograms, samples were also screened for the presence of other type-A trichothecenes, namely neosolaniol, diacetoxyscirpenol and their monoglucosyl derivatives, which were detected at trace levels. A subset of nine different samples was subjected to micro-maltation in order to carry out a preliminary investigation on the fate of T-2, HT-2 and relevant glucosides along the malting process. Mycotoxin reduction from cleaned barley to malt was observed at rates ranging from 4% to 87%.

A total of 120 pelleted poultry feed samples from Entre Ríos Province, Argentina, were evaluated. The aims were to investigate (1) the presence of relevant toxigenic fungi, as well as to determine the ability to produce aflatoxins (AFs) by Aspergillus section Flavi isolated strains; and (2) the natural co-occurrence of AFs, fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 and T-2 toxin by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS). Total fungal counts were below the established value (1 × 104 CFU g−1). Aspergillus flavus and A. parasiticus were the only aflatoxigenic species isolated. Co-occurrence of fumonisin B1 (FB1), HT-2 and T-2 toxin was detected in 100% of the feeds, with mean levels from 4502 to 5813; 6.7 to 21.6 and 19.6 to 30.3 µg kg−1, respectively. A large number of starter samples were co-contaminated with aflatoxin B1 (AFB1), FB1, HT-2 and T-2 toxins. Gliotoxin and DAS were not found in this survey. Fil: Monge, Maria del Pilar. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Dalcero, Ana Maria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Magnoli, Carina Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fusarium equiseti and Fusarium semitectum represent the most abundant species in the Fusarium complex isolated from flowers, soybean pods and seeds in Argentina. The aim of the present study was to assess the production of major type A and type B trichothecenes (diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin, nivalenol, deoxynivalenol) and zearalenone by 40 F. equiseti and 22 F. semitectum isolates on rice culture. Mycotoxins were determined by HPLC with fluorescence detection after derivatisation with 1-anthronylnitrile for type A trichothecenes (i.e. diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin), by HPLC with UV detection for type B trichothecenes (i.e. nivalenol and deoxynivalenol), and by TLC for zearalenone. A total of 22 of 40 F. equiseti isolates produced diacetoxyscirpenol, nivalenol and ZEA alone or in combination, whereas only two of 20 F. semitectum isolates were nivalenol and ZEA producers. Both Fusarium species did not produce any deoxynivalenol, neosolaniol, T-2 toxin and HT-2 toxin. The variable retention in toxigenicity displayed by both fungal species suggests that these species have a saprophytic lifestyle in the soybean agroecosystem in Argentina.

The capabilities of seven Finnish Fusarium species to produce mycotoxins under controlled laboratory (in vitro) conditions as well as on barley and wheat in the field (in vivo) were studied using mass spectrometric methods. In addition, the contaminating Fusarium species of the in vivo samples were identified and quantified with morphological and real-time polymerase chain reaction techniques. All investigated isolates (representing the species F. avenaceum, F. arthrosporioides, F. tricinctum, F. poae, F. culmorum, F. graminearum and F. sporotrichioides) produced mycotoxins on rice cultures and their production capabilities were generally in accordance with the available literature. The main mycotoxins produced were deoxynivalenol, 3-acetyldeoxynivalenol and zearalenone by F. culmorum and F. graminearum, beauvericin, diacetoxyscirpenol and HT-2/T-2 – toxins by F. sporotrichioides, beauvericin, enniatins, fusarenon-X, diacetoxyscirpenol and nivalenol by F. poae and enniatins and moniliformin by F....

One hundred and twenty-seven isolates of Fusarium pseudograminearum were obtained from seeds and vegetative parts of cereals and other gramineae grown in western Canada. Culture of the isolates on agar selective for Fusarium graminearum allowed a successful differentiation from F. graminearum. Sterilized rice (40% moisture content) was inoculated with a single germinated spore of isolates identified as F. pseudograminearum and was incubated at 23 °C. After 14 days of incubation, mycelium was taken from each culture, and the DNA was extracted to detect the tri5 gene by polymerase chain reaction analysis and confirm the species identity. After 21 days of incubation, mycotoxins were quantified in dried rice. All isolates contained the tri5 gene. Deoxynivalenol (DON) was produced in 125 of the 127 isolates, 3-acetyldeoxynivalenol (3-ADON) in 122 isolates, 15-acetyldeoxynivalenol (15-ADON) in 2 isolates, diacetoxyscirpenol (DAS) in 17 isolates, and zearalenone in 100 isolates; both nivalenol (NIV) and fusareno...

The major products of the trichothecene mycotoxin biosynthetic pathway produced in a species- and sometimes isolate-specific manner by cereal-pathogenic Fusarium fungi include T-2 toxin, diacetoxyscirpenol, deoxynivalenol and nivalenol. This paper briefly reviews the major effects of such trichothecenes on the gross morphology, cytology and molecular signalling within eukaryotic cells. The gross toxic effects of select trichothecenes on animals include growth retardation, reduced ovarian function and reproductive disorders, immuno-compromization, feed refusal and vomiting. The phytotoxic effects of deoxynivalenol on plants can be summarized as growth retardation, inhibition of seedling and green plant regeneration. Trichothecenes are now recognized as having multiple inhibitory effects on eukaryote cells, including inhibition of protein, DNA and RNA synthesis, inhibition of mitochondrial function, effects on cell division and membrane effects. In animal cells, they induce apoptosis, a programmed cell death response. Current knowledge about the eukaryotic signal transduction cascades and downstream gene products activated by trichothecenes is limited, especially in plants. In mammalian cells, certain trichothecenes trigger a ribotoxic stress response and activate mitogen-activated protein kinases. DON mediates the inflammatory response by modulating the binding activities of specific transcription factors and subsequently inducing cytokine gene expression. Several genes are up-regulated in wheat in response to trichothecene mycotoxins; the significance, if any, of these genes in the host response to trichothecenes has yet to be elucidated.

1. The effects of feeding T-2 toxin or diacetoxyscirpenol (DAS) at levels up to 1 ppm for 32 d on performance, health, small intestinal physiology and immune response to enteral and parenteral immunisation were examined in young poults. 2. Slight improvement in growth was observed in some groups of poults fed T-2 or DAS mycotoxins for 32 d, with no change in feed efficiency. Feeding both T-2 and DAS resulted in oral lesions which had maximal severity after 7-15 d. 3. Mild intestinal changes were observed at 32 d but no pathological or histopathological lesions were found. Both mycotoxins altered small intestinal morphology, especially in the jejunum where villi were shorter and thinner. In addition, both DAS and T-2 mycotoxins enhanced the proportion of proliferating cells both in the crypts and along the villi. Migration rates were reduced in the jejunum of poults fed T-2 toxin but did not change in the duodenum or in poults fed DAS. 4. No significant effects of T-2 or DAS were observed on antibody production to antigens administered by enteral or parenteral routes. 5. This study indicates that tricothecene toxins at concentrations of up to 1 ppm for more than 30 d influenced small intestinal morphology but did not affect growth or antibody production.

This study was conducted to examine the ability of selected strains of Lactobacillus and Propionibacterium to remove common Fusarium toxins, trichothecenes, from liquid media. The trichothecenes studied were deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), nivalenol (NIV), fusarenon (FX), diacetoxyscirpenol (DAS), T-2 toxin (T-2) and HT-2 toxin (HT-2). The Lactobacillus rhamnosus strain GG (LGG), Lactobacillus rhamnosus strain LC-705 (LC-705) and Propionibacterium freudenreichii ssp. shermanii JS (PJS) were incubated in PBS buffer containing 20 microg toxin ml(-1) for 1h at 37 degrees C, and after centrifugation the concentration of the toxins was measured in the supernatant fraction. Both viable and heat-killed forms of LGG and PJS were more efficient than LC-705 in removing the toxins from the liquid media. LGG and PJS removed four of the seven tested toxins (the removal varying from 18 to 93%) and LC-705 two toxins (10-64%). Of the toxins, 3-AcDON was not removed by any of the bacteria; HT-2 was removed by the non-viable LGG and also slightly by non-viable LC-705; DAS was removed by all three bacteria tested. Binding is postulated as the possible mechanism of the removal, since no difference was observed between the ability of viable and heat-killed bacteria in removing the trichothecenes, and no degradation products of the toxins were detected by gas chromatography (GC)-mass spectrometry (MS) analysis. It is concluded that significant differences exist in the ability of the bacteria to bind trichothecenes in vitro.

A total of 53, 54, 57, 52 and 60 wheat samples for feed use were collected randomly after the 1989, 1990, 1991, 1992 and 1993 crops, respectively, from farms in an area of southwest Germany. Deoxynivalenol (DON), 3- and 15-acetyldeoxynivalenol (3-, 15-ADON), nivalenol (NIV), HT-2 toxin (HT-2), T-2 toxin (T-2), diacetoxyscirpenol (DAS), and fusarenon-X (FUS-X) were determined by gas chromatography, combined with mass selective detection (GC-MS), zearalenone (ZEA), alpha- and beta-zearalenol (alpha-beta-ZOL) were determined by HPLC. DON was the major toxin, with incidences at 77 to 93% and mean contents at 167 to 735 micrograms/kg. In contrast, incidences of ZEA, 3-ADON, NIV, HT-2, and T-2 were at 13 to 37%, 10 to 44%, 15 to 67%, 0 to 11%, and 0 to 12%, respectively, with mean contents in positive samples between 2 and 73 micrograms/kg, except for 948 micrograms/kg 3-ADON in samples from 1993. 15-ADON and FUS-X were assayed in samples from 1991, 1992 and 1993. 15-ADON was found in 0 to 11% of samples at mean levelsor = 17 mu/kg, DAS, alpha- and beta-ZOL, and FUS-X were not detected in any sample. Over the years, incidences and levels of toxins remained constant, decreased or increased, with most differences between years being slight and insignificant. The risk for livestock due to DON, HT-2 and ZEA was estimated based on maximum tolerated levels recommended for these toxins in some countries.

The study of eight mycotoxins from Fusarium spp. at concentrations ranging from 0 to 4.3 mg/L for deoxynivalenol, 3-acetyldeoxynivalenol, nivalnol, and a culture filtrate, and from 0 to 14.3 mg/L for T2 toxin, HT2 toxin, diacetoxyscirpenol, and zearalenone, demonstrate that trichothecenes are phytotoxic. The inhibition of coleoptile elongation by each trichothecene is well described by a linear equation and these compounds show differences in phytotoxicity. Deoxynivalenol and 3-acetyldeoxynivalenol are 2.5 times more toxic than T2 toxin, 8 times more toxic than HT2 toxin, and 13 times more toxic than diacetoxyscirpenol. The culture filtrate, which contains deoxynivalenol and 3-acetyldeoxynivalenol, is the most toxic to the coleoptile. A mixture of four purified trichothecenes, deoxynivalenol, 3-acetyldeoxynivalenol, T2 toxin, and nivalenol, revealed differences in trichothecene susceptibility among 11 wheat cultivars. Moreover, reduction of coleoptile elongation of these cultivars was correlated with scab...

The fusarial toxicosis induced by trichothecenes is characterized by common syndromes such as vomiting, inflammation, haemorrhages, diarrhoea and haematological changes. Subchronic ingestion of trichothecenes causes a decrease in circulating white cells. This leukopenic change of animals is reported as a characteristic feature in the best known human disorder: Alimentary Toxic Aleukia (ATA). The aim of the present study was to evaluate whether the haematologic disorders imputed to trichothecenes were a result of myelotoxicity by investigating in an in vitro model. Rat haematopoietic progenitors, Colony Forming Units-Granulocytes and Macrophages (CFU-GM), were cultured in the presence of several concentrations of four trichothecenes; T-2 toxin, HT-2 toxin, diacetoxyscirpenol (DAS) and deoxynivalenol (DON). All these trichothecenes were cytotoxic to rat haematopoietic progenitor cells. It is concluded that haematological disorders observed during trichothecene intoxication of animals are caused by the destruction of haematopoietic progenitors such as CFU-GM cells.

The culture of human haematopoietic progenitors, Colony-Forming-Unit Granulocyte and Macrophage (CFU-GM), has been performed in the presence of four trichothecenes, T-2 toxin, HT-2 toxin, diacetoxyscirpenol (DAS), and deoxynivalenol (DON). Our results showed that trichothecenes were cytotoxic for human haematopoietic progenitors. This work and the analysis of results described in the literature allowed us to propose that the haematologic lesions observed during human intoxication could be due to a destruction of haematopoietic progenitors such as granulocytic and macrophage colony-forming cells.

Australian isolates of Fusarium species were grown on potato dextrose agar. Trichothecenes produced by these species were extracted by ethyl acetate followed by methanol and a silica gel column was used to clean-up the extract. The extracted samples were derivatized by acetylation with trifluoroacetic anhydride and the derivatives analysed by gas chromatography/mass spectrometry (GC/MS). Multiple ion detection was used to trace ions characteristic of the trichothecenes expected to be present. Quantitation of those found was based on a known mass of pentabromophenol that was added as an internal standard. Eight species of Fusarium (nineteen strains) were surveyed, of which three species, F. acuminatum, F. equiseti and F. sporotrichioides, produced the trichothecenes scirpentriol, diacetoxyscirpenol, neosolaniol, HT-2 toxin, T-2 toxin, T-2 tetraol and deoxynivalenol. Wheat samples were inoculated with four different species of Fusarium, F. acuminatum, F. equiseti, F. graminearum and F. sporotrichioides, and in these samples diacetoxyscirpenol, neosolaniol, HT-2 toxin and T-2 toxin were found.

2-(Diphenylacetyl)-1,3-indanedione-1-hydrazone and its derivatives where the NH2 has been replaced by a substituted NH or an imino group give fluoresence enhancement with trichothecene mycotoxins. Absolute amounts of T-2 toxin as low as 50 ng are detectable. Detection limits for HT-2, Diacetoxyscirpenol, Neosolaniol, and Fusarenon-X range from 0.1 to 4μg. The advantage in using 2-(diphenylacetyl)-1,3-indanedione-1-hydrazone (DIPAIN) derivatives for the detection of trichothecene mycotoxins is that response time is based on the rate of formation of a molecular association complex between the toxin and the detector reagent rather than on the chemical reactivity of the toxin. Hence, sensitive detection or mycotoxins can be achieved simply and rapidly at 25°C. Since DlPAlN derivatives have been found to be direct-acting reagents capable of detecting droplets of dissolved trichothecenes, it is speculated that they may be useful as coatings in optical waveguide devices or in other devices that are deve...

The development of test strip enzyme immunoassays (EIA) for the rapid detection of a number of mycotoxins is described. Monoclonal or polyclonal antibodies against aflatoxin B1 (AFB1), aflatoxin M1 (AFM1), ochratoxin A (OA), T‐2 toxin, diacetoxyscirpenol (DAS), 3‐acetyldeoxynivalenol (3‐AcDON), roridin A (RA) and zearalenone (ZEA) were immobilized on a nylon membrane. Using the corresponding toxin‐horseradish peroxidase conjugate in a direct competitive assay, dot colour development of toxinpositive test strips was visually discernible from that of the negative control. The results of the visual evaluation were compared with that of instrumental reflectance measurements of the test strips. The visual detection limits of the test strip assays for mycotoxins were at 0.6 ng ml−1 (AFB1) 0.2 ng ml−1 (AFM1), 2.0 ng ml−1 (OA), 1.0 ng ml−1(T‐2 toxin), 0.2 ng ml−1 (DAS), 10.0 ng ml−1 (3‐AcDON), 15.0 ng ml−1 (RA), and 5.0 ppb (ZEA) respectively. Utilizing a simple extraction procedure, AFB1, OA, T‐2 toxin, and ZEA ...

We studied the secondary metabolites of a number of strains of E venenatum, some of which had the gene for trichodiene synthetase deleted. Un- der optimum fermentation conditions, wild type iso- lates produced the trichothecenes diacetoxyscirpenol and related metabolites, isotrichodermin and isotri- codermol, the modified trichothecenes sambucinol and apotrichothecene, the sesquiterpenes culmorin and culmorone and derivatives and trace amounts of the cyclic peptide enniatin B. These results are com- pared to metabolite production by other members of the section Discolor. Strains without trichodiene syn- thetase produced no trichothecenes or modified trichothecenes. In these strains, production of cul- morin family compounds was greatly attenuated de- spite the elimination of an acetate-derived biosyn- thetic pathway. This was contrary to expectations. No other metabolites were produced by these strains ev- idenced by chemical or cytotoxicity analyses of frac- tionated extracts.

Metabolites of Fusarium (R.F. Vesonder, P. Golinski). Fusarin C (J.M. Farber, P.M. Scott). Mycotoxins associated with corn cob fusariosis (J. Chelkowski). Formation of mycotoxins produced by Fusaria in heads of wheat, triticale and rye (J. Chelkowski). Fusarium species and their mycotoxins in infected cereals in the field and in stored grains (A. Bottalico et al.). Application of Artemia salina L. bioassay for screening of Fusaria toxins (R. Schmidt). Trichothecene poisonings on fish (E.-L. Hintikka). Metabolism of the trichothecenes T-2 toxin, diacetoxyscirpenol and deoxynivalenol by farm animals (J. Bauer et al.). Metabolism of zearalenone in farm animals (M. Olsen). Identification of Fusaria occurring in Europe on cereals and potatoes (H.I. Nirenberg). Taxonomy and nomenclature of Microdochium nivale (Fusarium nivale) (W. Gams). Fusarium species and their specific profiles of secondary metabolites (U. Thrane). Growth regulators formed by Fusaria: their significance for fungus growth, sporulation and pathogenicity towards the host plant (M. Michniewicz). The role of cutinase and cell wall degrading enzymes produced by Fusaria in pathogenesis (H. Urbanek). Phytotoxicity of Fusarium metabolites in relation to pathogenicity (W. Wakulinski). Epidemiology of wheat (Triticum aestivum L.) scab caused by Fusarium spp. (A.H. Teich). Fusarium diseases of wheat and triticale in some regions of Eastern Europe (B. Lacicowa). Maize diseases caused by Fusaria: involved species and mycotoxins (W. Kruger). Epidemiology of corn (Zea mays L.) ear rot caused by Fusarium spp. (A.H. Teich). Fusaria as pathogens of cereal seedlings (M. Manka). Progress in breeding of wheat and corn genotypes not susceptible to infection by Fusaria (A. Mesterhazy). Fusaria as hyperparasites of Claviceps species (B.M. Cunfer). Fate of Fusarium mycotoxins in cereals during food processing and methods for their detoxification (A.L. Patey, J. Gilbert). Fusaria as pathogens of potato tubers and their pathogenicity (E. Seppanen). Toxinogenicity of Fusarium species causing dry rot of potato tubers (J. Chelkowski). Contamination of cereals and feed with Fusarium mycotoxins in European countries (M. Gareis et al.). Glossary. Subject Index.

A method for the quantitative determination of the toxic fungal products diacetoxyscirpenol and T-2 toxin is described. Initially intended for the screening of fungal cultures grown on maize, it has subsequently been used successfully for the analysis of maize and oat grain samples. The method involves extraction with aqueous methanol followed by a two-stage clean-up procedure utilizing a commercial kieselguhr column and a silica gel cartridge. The heptafluorobutyryl derivatives of the trichothecenes, including neosolaniol monoacetate used as an internal standard, are separated on a 25 m X 0.32 mm SE-30 fused silica capillary column and measured with a 63Ni electron capture detector. The quantitative detection limit was found to be of the order of 200 ng/g (ppb) with an average recovery from maize of 88% for both toxins. The method was found to be rapid and practical with the advantage that the kieselguhr packing material could be easily regenerated and re-used. The method was compared with those reported in the literature which are currently in use.

Mass spectra of the trifluoroacetyl esters of the trichothecenes deoxynivalenol, diacetoxyscirpenol and T-2 toxin, as well as zearalenone, were obtained by gas chromatography-electron ionization mass spectrometry. Quantitation of deoxynivalenol as its trifluoroacetyl ester by selected ion monitoring was then possible down to 10 pg in the mass spectrometer (equivalent to 1 ng/g in a sample). The method was tested by extracting and analysing mouldy wheat which had previously given a positive result for deoxynivalenol when analysed by thin layer chromatography. The method was also suitable for the analysis of diacetoxyscirpenol and T-2 toxin; however, quantitation of zearalenone was unsuccessful because of the instability of the derivative.

Airborne occurrence of mycotoxins in agricultural and residential environments has generated concern that these toxins may be absorbed via the skin and respiratory tract. This paper summarizes information available on the in vivo and in vitro cutaneous permeability of several mycotoxins (aflatoxin, T-2 toxin [T-2], diacetoxyscirpenol, and verrucarin A).Published data is used to calculate the dose absorbed during cutaneous exposure to fungal toxins in hypothetical agricultural and research laboratory environments. These estimated doses of T-2 (0.004 and 0.041 μg/kg, respectively) were 25,000 and 2,439 times less than a reported oral dose (100 μg T-2/kg/day) which caused immunosuppression in monkeys.In general, exposure of human skin to aflatoxin and trichothecenes results in slow absorption. The risk of systemic toxicity resulting from dermal exposure increases in the presence of high toxin concentrations, occlusion, and vehicles which enhance penetration.

Twenty samples of maize collected from healthy growing crops and at harvest time and during storage were screened for four Fusarium toxins (deoxynivalenol, diacetoxyscirpenol, T-2 toxin and zearalenone) by gas chromatography-mass spectrometry and thin-layer chromatography. Seventeen samples (85%) contained one or more of these toxins. Zearalenone was present in 15 samples at levels ranging between 0.1 and 16 ppm. Deoxynivalenol, diacetoxyscirpenol and T-2 toxin were found in 11, 6 and 13 samples respectively, all at levels below 1 ppm. This work documents the first reported natural occurrence of Fusarium toxins in New Zealand maize, and it is concluded that all four of the mycotoxins studied are prevalent in apparently healthy standing crops as well as in stored maize.

A previously published method for the determination of deoxynivalenol (DON) and nivalenol (NIV) in grains by capillary gas chromatography (GC) with electron-capture detection (ECD) has been modified to include HT-2 toxin (HT-2), T-2 toxin (T-2) and diacetoxyscirpenol (DAS). Recoveries of the five trichothecenes from wheat averaged 71-92% in the range 0.8-4 micrograms/g. Detection or quantitation limits found in two laboratories were from 0.02 to 0.4 micrograms/g, with those for T-2 and DAS at the high end of this range. The method proved of practical use in survey work for the screening and determination of these trichothecenes in wheat from the 1987 western Canadian crop. There were no false positives for HT-2, T-2 and DON in durum and HY-320 wheat. However, interferences precluded the determination of 4- and 15-monoacetoxyscirpenol (MAS) by GC-ECD. The natural occurrence of HT-2 toxin (0.06-0.59 micrograms/g) was demonstrated by GC-ECD and confirmed by GC-mass spectrometry (MS) in 23 samples of durum and HY-320 wheats (1986 and 1987 crops); it was almost always accompanied by DON and in one sample a low concentration of NIV (0-05 micrograms/g). False positives for HT-2 and DAS in red spring wheat detected in 1987 by GC-ECD were 6% (nearly all identified as variety Katepwa) and 8%, respectively. Hence confirmation of suspected HT-2 and DAS by GC-MS is necessary, particularly with red spring wheat.