Natural occurrence of type-B trichothecene mycotoxins in Korean cereal-based products

Type-B trichothecenes (deoxynivalenol (DON), nivalenol (NIV), fusarenone-X (FUS-X), 15-acetyldeoxynivalenol (15ADON), and 3-acetyldeoxynivalenol (3ADON)) were determined in 338 cereal-based products. Detection limit, quantification limit and mean recovery for five toxins were in the ranges 0.7–2.6?µg?kg^?1, 2.1–7.8?µg?kg^?1 and 73–110%, respectively. The range of occurrence and average level in samples were, respectively, 21–88% and 5.2–121.8?µg?kg^?1 for NIV, 10–96% and 1.7–109.5?µg?kg^?1 for DON, 2–39% and 0.4–3.6?µg?kg^?1 for FUS-X, 0–80% and 0–17.3?µg?kg^?1 for 15ADON, and 0–29% and 0–1.5?µg?kg^?1 for 3ADON. Regarding co-occurrence, 64% of samples had more than two type-B trichothecenes. The estimated daily intakes of NIV, DON, FUS-X, 15ADON, and 3ADON were 0.077, 0.048, 0.004, 0.006 and 0.002?µg?kg^?1?bw?day^?1, respectively. These results suggest that current exposure levels do not indicate the possibility of adverse effects, but consideration of the combined exposure of type-B trichothecenes may be required due to the high frequency of co-occurrence.     

An immunogen synthesis strategy for the development of specific anti-deoxynivalenol monoclonal antibodies

An immunogen synthesis strategy was designed to develop anti-deoxynivalenol (DON) monoclonal antibodies with low cross-reactivity against structurally similar trichothecenes. A total of eight different DON immunogens were synthesised, differing in the type and position of the linker on the DON molecule. After immunisation, antisera from mice immunised with different DON immunogens were checked for the presence of relevant antibodies. Then, both homologous and heterologous enzyme-linked immunosorbent assays (ELISAs) were performed for hybridoma screening. Finally, three monoclonal antibodies against DON and its analogues were generated. In addition, monoclonal antibody 13H1 could recognise DON and its analogues in the order of HT-2 toxin > 15-acetyldeoxynivalenol (15-ADON) > DON, with IC₅₀ ranging from 1.14 to 2.13 µg ml^–1. Another monoclonal antibody 10H10 manifested relatively close sensitivities to DON, 3-acetyldeoxynivalenol (3-ADON) and 15-ADON, with IC₅₀ values of 22, 15 and 34 ng ml^–1, respectively. Using an indirect ELISA format decreases the 10H10 sensitivity to 15-ADON with 92%. A third monoclonal antibody 2A9 showed to be very specific and sensitive to 3-ADON, with IC₅₀ of 0.38 ng ml^–1. Using both 2A9 and 10H10 monoclonal antibodies allows determining sole DON contamination.     

Natural occurrence of Fusarium toxins in oats harvested during five years in an area of southwest Germany.

A total of 56, 56, 54, 51, and 55 oats samples used for feed production were collected randomly after the 1987, 1989, 1990, 1991 and 1992 crops, respectively, from farms located in an area of southwest Germany. Deoxynivalenol (DON), 3- and 15-acetyl-deoxynivalenol (3-, 15-ADON), nivalenol (NIV), fusarenon-X (FUS-X), T-2 toxin (T-2), HT-2 toxin (HT-2) and diacetoxyscirpenol (DAS) were determined by gas chromatography with mass selective detection (GC-MS), zearalenone (ZEA), alpha and beta-zearalenol (alpha-, beta-ZOL) by GC-MS or by HPLC. DON was the major toxin with incidences at 49-85% and mean levels in positive samples of 52-302 micrograms/kg. Incidences of ZEA, 3-ADON, NIV, HT-2, and T-2 were at 20-37, 0-30, 18-67, 0-29, and 27-61%, respectively, with mean levels in positive samples at 8-25, 5-63, 11-192, 205-296, and 20-244 micrograms/kg, respectively. alpha- and beta-ZOL and DAS were not detected in any sample. 15-ADON and FUS-X were assayed in samples from 1987, 1991 and 1992. 15-ADON was detected in 9, 4 and 0% of samples, with an average of 9 and 18 micrograms/kg, respectively; FUS-X was not detected. The incidence and levels of toxins varied from year to year. The correlation between the occurrence of toxins and precipitation is discussed.     

Survey of Fusarium toxins in foodstuffs of plant origin marketed in Germany

A total of 219 samples of foodstuffs of plant origin, consisting of grain-based food, pseudocereals and gluten-free food as well as vegetables, fruits, oilseeds and nuts, were randomly collected during 2000 and 2001 in food and health food stores. A spectra of 13 trichothecene toxins including diacetoxyscirpenol (DAS), 15-monoacetoxyscirpenol (MAS), scirpentriol (SCIRP), T-2 and HT-2 toxins (T-2, HT-2), T-2 triol, T-2 tetraol, neosolaniol (NEO) of the A-type as well as deoxynivalenol (DON), 3- and 15-acetyl-DON (3-, 15-ADON), nivalenol (NIV), and fusarenon-X (FUS-X) of the B-type were determined by gas chromatography/mass spectrometry. Analysis of zearalenone (ZEA), alpha- and beta-zearalenol (alpha- and beta-ZOL) was made by high-performance liquid chromatography with fluorescence and UV-detection. Detection limits ranged between 1 and 19 microg/kg. Out of 84 samples of cereal-based including gluten-free foods, 60 samples were positive for at least one of the toxins DON, 15-ADON, 3-ADON, NIV, T-2, HT-2, T-2 tetraol and ZEA, with incidences at 57%, 13%, 1%, 10%, 12%, 37%, 4% and 38%, respectively, whereas SCIRP and its derivatives MAS and DAS, T-2 triol, Fus-X as well as alpha- and beta-ZOL were not detected in any sample of this subgroup. Contents of DON ranged between 8 and 389 microg/kg, for all other toxins determined concentrations were below 100 microg/kg. The pseudocereals amaranth, quinoa and buckwheat were free of the toxins investigated. Ten of 85 samples of vegetables and fruits were toxin positive. ZEA and the type A trichothecenes MAS, SCIRP, DAS, HT-2 were detected in 7, 3, 2, 1 and 1 samples, respectively. Out of 35 samples of oilseeds and nuts, 7 samples were toxin positive. HT-2, T-2 and ZEA were detected in 4, 3 and 4 samples, respectively. In vegetables and fruits as well as in oilseeds and nuts, toxin levels were below 50 microg/kg. None of the B-type trichothecenes analysed was found for both subgroups.     

Deoxynivalenol,zearalenone and T-2 in grain based swine feed in Hungary

Fusarium genera can produce trichothecenes like deoxynivalenol (DON), zearalenone (ZEN) and T-2 toxin, which can occur in feed cereal grains. Enzyme-linked immunosorbent assays (ELISA) tests of different Hungarian swine feedstuff proved that these mycotoxins were present. In this survey, 45 feed samples from 3 significant Hungarian swine feedstuff manufacturers were tested. ELISA methodology validation showed mean recovery rates in ranges from 85.3% to 98.1%, with intermediate precision of 86.9-96.9% and variation coefficients of 3.4–5.7% and 5.9–7.1%, respectively. The results showed that among Fusarium toxins, generally DON was present in the highest concentration, followed by T-2 and finally ZEN in all tested swine feeds. Each of the mycotoxins was found above the limit of detection in all swine feedstuffs. Boars feed’s DON (average ± standard deviation was 872 ± 139 µg kg^?1) and ZEN (172 ± 18 µg kg^?1) results of one of the manufacturers were above the guidance values. It indicates the necessity for efficient monitoring of DON, ZEN and T-2 mycotoxins in swine feeds.     

Co-occurrence and distribution of deoxynivalenol,nivalenol and zearalenone in wheat from Brazil

Fusarium mycotoxins deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) were investigated in wheat from the 2009 and 2010 crop years. Samples (n = 745) from commercial fields were collected in four wheat producing regions (WPR) which differed in weather conditions. Analyses were performed using HPLC-DAD. Contamination with ZEN, DON and NIV occurred in 56, 86 and 50%, respectively. Also, mean concentrations were different: DON = 1046 µg kg^?1, NIV < 100 µg kg^?1 and ZEN = 82 µg kg^?1. Co-occurrence of ZEN, DON and NIV was observed in 74% of the samples from 2009 and in 12% from 2010. Wet/cold region WPR I had the highest mycotoxin concentration. Wet/moderately hot region WPR II had the lowest mycotoxin levels. Furthermore, the mean concentration of each mycotoxin was higher in samples from 2009 as compared with those from 2010. Precipitation during flowering or harvest periods may explain these results.     

Co-occurrence of Fusarium mycotoxins in mouldy and healthy corn from Korea

A total of 71 samples consisting of 36 mouldy and 35 visibly healthy corn were collected from Kangwon province of Korea and analysed for 8-ketotrichothecenes, zearalenone (ZEA), and fumonisins, including fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3). Five 8-ketotrichothecenes, namely deoxynivalenol (DON), 15-acetyldeoxynivalenol (15-ADON), 3-acetyldeoxynivalenol (3-ADON), nivalenol (NIV), and 4-acetylnivalenol (4-ANIV), ZEA, FB1, FB2, and FB3 were detected in corn samples. DON, 15-ADON, 3-ADON, NIV, 4-ANIV, ZEA, FB1, FB2, and FB3 were detected in mouldy corn with mean values of 4.0, 0.9, 0.2, 1.7, 0.4, 0.6, 23.2, 7.5, and 6.3mug/g, respectively. Visibly healthy corn samples were contaminated with lower levels of 8-ketotrichothecenes, ZEA, and fumonisins than mouldy corn samples. However, 5 of 35 healthy corn samples analysed were contaminated with fumonisins at high levels up to 12.5mug/g for FB1, 5.4mug/g for FB2, and 0.5mug/g for FB3. This is the first report on the simultaneous occurrence of trichothecenes, ZEA, and fumonisins in corn from Korea.     

Survey of 11 mycotoxins in wheat flour in Hebei province,China

A survey of 11 mycotoxins in 348 wheat flour samples marketed in Hebei province of China were analysed by liquid chromatography-tandem mass spectrometry, was carried out. The selected mycotoxins consisted of four aflatoxins (AFs: AFB₁, AFB₂, AFG₁ and AFG₂) and seven Fusarium toxins, i.e. deoxynivalenol (DON), nivalenol, 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol, zearalenone, Fusarenon-X and deoxynivalenol-3-glucoside. Results indicated that most of the wheat samples analysed were contaminated with mycotoxins. Wheat was most susceptible to DON (91.4% contamination), with a mean level of 240 μg kg^?1. On average the probable daily intake (PDI, expressed as µg kg^?1 body weight day^?1) of mycotoxins was within the provisional maximum tolerable daily intake (PMTDI, 2.0 µg kg^?1 of body weight day^?1) as set by the Joint FAO/WHO Expert Committee on Food Additives. Nevertheless, exposure assessment revealed that the maximum PDI of mycotoxins was 4.06 µg kg^?1 body weight day^?1, which was twice the PMTDI value. Thus, consistent monitoring is recommended, as to keep the contamination level under control.     

The prevalence of deoxynivalenol and its derivatives in the spring wheat grain from different agricultural production systems in Lithuania

Deoxynivalenol (DON) together with two acetylated derivatives, 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) occurs in cereal grains and their products. Co-occurrence of DON and acetylated derivatives in cereal grain is detected worldwide. Until now, DON and its derivatives have been considered equally toxic by health authorities. In this study, we analysed 103 samples of spring wheat grain, originating from the fields of different production systems in Lithuania, for the co-occurrence of type-B trichothecenes (DON, 3-ADON, 15-ADON). The samples were classified according to the production system—organic, sustainable and intensive. Mycotoxin levels in the spring wheat grain samples were determined by the HPLC method with UV detection. The type-B trichothecenes were found to be present at higher concentrations in the grain from the intensive production system. Eighty-one percent of the spring wheat grain samples from the intensive production system were co-contaminated with a combination of DON+3-ADON+15-ADON, 1% with DON+3-ADON. Additionally, DON+15-ADON and DON were found in 5% and 10% of the tested samples, respectively. Two percent of the samples were free from mycotoxins. In the grain samples from the sustainable production system, DON and a combination of DON+3-ADON showed a higher incidence – 47% and 23%, respectively. The samples with a combination of DON+3-ADON+15-ADON accounted for 18%. Completely different results were obtained from the analyses of organic grain samples. A large number of the organic spring wheat grain samples were contaminated with DON+3-ADON (55%) or DON (36%). The combination of DON+3-ADON+15-ADON was not present, while DON+15-ADON was present in 9% of the samples tested. The production systems did not lead to significant differences in mycotoxin levels, although a trend toward higher incidence and higher contamination was observed for the samples from the intensive and sustainable production systems.     

Determination of trichothecenes in cereals and cereal-based products by liquid chromatography–tandem mass spectrometry

A sensitive, accurate and precise method for the simultaneous determination of nivalenol (NIV), deoxynivalenol (DON), T-2 toxin (T-2) and HT-2 toxin (HT-2) in different food matrices, including wheat, maize, barley, cereal-based infant foods, snacks, biscuits and wafers, has been developed. The method, using liquid chromatography coupled with atmospheric pressure chemical ionization triple quadrupole mass spectrometry (LC–APCI–MS/MS), allowed unambiguous identification of the selected trichothecenes at low µg per kg levels in such complex food matrices. A clean-up procedure, based on reversed phase SPE Oasis® HLB columns, was used, allowing good recoveries for all studied trichothecenes. In particular, NIV recoveries significantly improved compared to those obtained by using Mycosep® #227 columns for clean-up of the extracts. Limits of detection in the various investigated matrices ranged 2.5–4.0 µg kg^?1 for NIV, 2.8–5.3 µg kg^?1 for DON, 0.4–1.7 µg kg^?1 for HT-2 and 0.4–1.0 µg kg^?1 for T-2. Mean recovery values, obtained from cereals and cereal products spiked with NIV, DON, HT-2 and T-2 toxins at levels from 10 to 1000 µg kg^?1, ranged from 72 to 110% with mean relative standard deviation lower than 10%. A systematic investigation of matrix effects in different cereals and cereal products was also carried out by statistically comparing the slopes of standard calibration curve with matrix-matched calibration curve for each of the four toxins and the eight matrices tested. For seven of the eight matrices tested, statistically significant matrix effects were observed, indicating that, for accurate quantitative analysis, matrix-matched calibration was necessary. The method was applied to the analysis of 57 samples of ground wheat originated from South Italy and nine cereal food samples collected from retail markets.     

Determination of glyphosate,AMPA, and glufosinate in honey by online solid-phase extraction-liquid chromatography-tandem mass spectrometry

A simple method was developed for the simultaneous determination of glyphosate, its main degradation product (aminomethylphosphonic acid), and glufosinate in honey. Aqueous honey solutions were derivatised offline prior to direct analysis of the target analytes using online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry. Using the developed procedure, accuracies ranging from 95.2% to 105.3% were observed for all analytes at fortification levels of 5, 50, and 150 μg kg^?1 with intra-day precisions ranging from 1.6% to 7.2%. The limit of quantitation (LOQ) was 1 μg kg^?1 for each analyte. Two hundred honey samples were analysed for the three analytes with AMPA and glyphosate being most frequently detected (99.0% and 98.5% of samples tested, respectively). The concentrations of glyphosate were found to range from <1 to 49.8 μg kg^?1 while those of its degradation product ranged from <1 to 50.1 μg kg^?1. The ratio of glyphosate to AMPA was found to vary significantly amongst the samples where both analytes were present above the LOQ. Glufosinate was detected in 125 of 200 samples up to a maximum concentration of 33.0 μg kg^?1.     

Occurrence of Fusarium species and trichothecenes in Nigerian maize

A total of 180 maize samples meant for human consumption from four maize-producing states of southwestern Nigeria were screened for twelve major Fusarium mycotoxins (trichothecenes). Mycological examination of the samples showed that Fusarium verticillioides was the most commonly isolated fungi (71%), followed by F. sporotrichioides (64%), F. graminearum (32%), F. pallidoroseum (15%), F. compactum (12%), F. equiseti (9%), F. acuminatum (8%), F. subglutinans (4%) and F. oxysporum (1%). The trichothecenes include deoxynivalenol (DON), 3, mono-acetyldeoxynivalenol (3-AcDON), 15, mono-acetyldeoxynivalenol (15-AcDON), nivalenol (NIV), HT-2 toxin (HT-2), neosolaniol (NEO), T-2 toxin (T-2), T-2 tetraol and T-2 triol, diacetoxyscirpenol (DAS), MAS-monoacetoxyscirpenol (MAS) and fusarenone-X. Quantification was by high performance liquid chromatography coupled with mass spectroscopy (HPLC/MS); the detection limits for each of the mycotoxins varied between 20 and 200 microg kg(-1). Sixty six samples (36.3%) were contaminated with trichothecenes, DON (mean: 226.2 microg kg(-1); range: 9.6-745.1 microg kg(-1)), 3-AcDON (mean: 17.3 microg kg(-1); range: 0.7-72.4 microg kg(-1)) and DAS (mean: 16.0 microg kg(-1); range: 1.0-51.0 microg kg(-1)) were detected in 22%, 17% and 9% of total samples respectively. There were no 15-AcDON, NIV, HT-2, NEO, T-2, T-2 tetraol, T-2 triol, MAS and fusarenone-X detected. This is the first comprehensive report about the natural occurrence of DON, AcDON and DAS in maize for direct human consumption in Nigeria.     

Changes in ochratoxin A and type B trichothecenes contained in wheat flour during dough fermentation and bread-baking

Ochratoxin A (OTA) and type B trichothecenes are mycotoxins that occur frequently in cereals and thus can be found in cereal by-products such as bread. The aim of this work was to study the variation of the levels of OTA, deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON) and nivalenol (NIV) during the bread-making process. This was done by using wheat flour spiked with different levels of toxins. Mycotoxin levels were controlled after fermentation of the dough with yeasts (Saccharomyces cerevisiae) and after further baking at different temperature–time combinations. Analysis of variance (ANOVA) of the results showed a significant reduction in OTA level (p < 0.05) during fermentation of the dough. The reduction ranged between 29.8% and 33.5%, depending on the initial concentration of toxin in the flour. During this period, the level of the other mycotoxins studied was not modified. By contrast, in the baking phase there were significant changes in the levels of the four mycotoxins, although the reduction was similar under all the baking conditions. Considering all the temperature–time conditions tested, it can be concluded that during the baking period the average reduction of OTA, NIV, 3-ADON, and DON was 32.9%, 76.9%, 65.6%, and 47.9%, respectively.     

Occurrence of deoxynivalenol in wheat flour,instant noodle and biscuits commercialised in Brazil

A total of 134 samples, consisting of 58 wheat flour, 40 instant noodle and 36 biscuits, were analysed for the presence of deoxynivalenol (DON). The samples were obtained from retail markets of the city of São Paulo during the period 2010–2014. DON was determined by high performance liquid chromatography with ultraviolet detection and immunoaffinity sample clean-up. Method validation followed international guidelines. The LOD and LOQ were 60 and 200 µg kg^?1, respectively, considering the three different types of samples analysed. The lowest recovery found in this study was 91.8% with RSD 4.5% for instant noodles. DON was detected in 91.4%, 97.5% and 97.2% of samples wheat flour, instant noodles and biscuits, respectively, resulting in a total of 94.8% with levels ranging from LOD to 1720.0 µg kg^?1.     

Simultaneous Determination of Deoxynivalenol,Deoxynivalenol-3-Glucoside and Nivalenol in Wheat Grains by HPLC-PDA with Immunoaffinity Column Cleanup

Deoxynivalenol-3-glucoside (D3G) is a modified mycotoxin formed by the metabolism of plants through the conjugation of deoxynivalenol (DON) with glucose. Toxicology studies of D3G for human and animal health are still under investigation, and the development of practical and reliable methods for its direct determination, especially in cereal matrices, is of great importance. In the present study, a methodology for simultaneous determination of D3G, DON, and nivalenol (NIV) in wheat grains, using immunoaffinity column (IAC) cleanup, separation by C18 column and detection by ultraviolet (UV) absorption, was optimized and in-house validated. The results demonstrated adequate values of D3G recovery from IAC and spiked samples. Intraday precision, linearity, limit of detection and limit of quantification (LOQ) were also adequate for the determination of these mycotoxins. Range of applicability varied from 47.1 to 1000 μg/kg for D3G and from 31.3 to 1000 μg/kg for DON and NIV, with recovery ranging from 84.7?±?7.2 % to 112.3?±?8.1 %. A high incidence of D3G (41.2 %, all samples <LOQ) was verified in commercial samples of wheat grains and whole wheat-flour (n?=?17). Also, the presence of D3G occurred simultaneously with DON in 100 % of the D3G-positive samples. DON levels varied from <LOQ to 325.8 μg/kg, and NIV was detected in only 29.5 % (from <LOQ to 140.6 μg/kg). To the best of our knowledge, this is the first method of simultaneous determination of NIV, D3G, and DON by high-performance liquid chromatography with photodiode array detector (HPLC-PDA) reported until now.     

Determination of trichothecenes in wheat by capillary gas chromatography with flame ionisation detection

Trichothecenes are mycotoxins produced by several fungal genera. The Fusarium species, mainly, can contaminate a wide range of cereals used for human and animal consumption. Trichothecenes are associated with various adverse health effects in animals and humans. Deoxynivalenol (DON) and nivalenol (NIV) are the trichothecenes most commonly found worldwide, although 3-acetyldeoxynivalenol, fusarenon X, T-2 toxin, HT-2 toxin, diacetoxyscirpenol (DAS) and neosolaniol are also found. They are included in the present study. For the determination of these trichothecenes in wheat, a method based on capillary gas chromatography (GC) with flame ionisation detection (FID) has been developed and validated. The trichothecenes are extracted from the sample matrix by acetonitrile/water (84/16, v/v). Two different Mycosep® clean-up columns are used to purify the extract. The extract is evaporated to dryness and the trichothecenes are derivatised to trimethylsilyl ethers at room temperature. The residue is dissolved in iso-octane and washed with water. The final extract is analysed for trichothecenes by GC with FID. Quantification is based on the internal standard α-chloralose. The average recoveries for the trichothecenes range from 79% for NIV to 116% for DAS. The limit of quantification is 75 μg/kg for each of the individual trichothecenes. The GC-FID method produced good results in an intercomparison study of trichothecene analysis within the European Union Standards, Measurements and Testing Programme. A survey was carried out in the Netherlands in 1999 to detect the presence of trichothecenes in imported wheat. A temporary tolerance limit of 500 μg/kg is in effect in the Netherlands for DON in cleaned wheat. Seven of the 22 wheat samples exceeded this limit; one exceeded the limit by more than 100%. Thirteen of the 22 wheat samples exceeded a proposed DON tolerance limit of 120 μg/kg for cleaned wheat. Indeed, 12 samples exceeded the limit by more than 100%. Besides DON, no trichothecenes were found in the wheat samples at levels above the limit of quantification.     

Determination and surveillance of hydrocortisone and progesterone in livestock products by liquid chromatography-tandem mass spectrometry

A simple analytical method for the determination of hydrocortisone and progesterone in bovine, swine, and chicken muscle and eggs was developed. Hydrocortisone and progesterone were extracted with acetonitrile and subsequently cleaned-up using an Oasis^® HLB mini-cartridge. The method was validated in accordance with Japanese guidelines and exhibited trueness from 86.6% to 104.3% and precision (relative standard deviations (RSDs) of repeatability and within reproducibility were under 8.7% and 11.7%, respectively). The method was applied to 103 bovine muscle, 137 swine muscle, 69 chicken muscle and 52 egg samples that were commercially available in Tokyo, Japan. The hydrocortisone concentration was 0.9–41.2 µg kg^?1 in all bovine muscle samples, with an average of 7.7 µg kg^?1 and a median of 6.2 µg kg^?1. The progesterone concentration in 50 samples exceeded the limit of quantification (LOQ) and reached a maximum of 95.4 µg kg^?1. Hydrocortisone was also detected in all swine muscle samples at concentrations of 2.0–56.0 µg kg^?1. Its average and median concentrations amounted to 13.1 and 11.3 µg kg^?1, respectively. Twenty-three samples contained progesterone levels surpassing the LOQ, with a maximum concentration of 107.0 µg kg^?1. No chicken muscle samples contained any of the analytes. The progesterone concentration was 15.5–200.0 µg kg^?1 in all egg samples, with an average of 95.4 µg kg^?1 and a median of 90.5 µg kg^?1.     

Trichothecene genotypes and chemotypes in Fusarium graminearum strains isolated from wheat in Argentina

Argentina is the fourth largest exporter of wheat in the world. The main pathogen associated with Fusarium Head Blight (FHB) of wheat in Argentina is Fusarium graminearum lineage 7 also termed F. graminearum sensu stricto in the F. graminearum species complex, which can produce the Type B trichothecenes, usually deoxynivalenol (DON) and its acetylated forms (3-ADON and 15-ADON) or nivalenol (NIV). We used a multiplex PCR assay of Tri3, Tri7, and Tri13 to determine the trichothecene genotype of 116 strains F. graminearum collected from three locations in Argentina and then verified the chemotype by chemical analysis. PCR assays and chemical analyses gave the same results for all strains that produced trichothecenes. Most strains (> 92%) had the 15-ADON genotype, with the remaining strains having the DON/NIV genotype. We observed neither the NIV nor the 3-ADON genotypes amongst the strains evaluated. The nine strains with the DON/NIV genotype produced DON when analyzed chemically. Thus, the Argentinean populations of F. graminearum are similar to those from wheat elsewhere in the world, in that all the strains produced DON/15-ADON and belong to lineage 7. However approximately 8% of the strains tested were incorrectly diagnosed as DON/NIV producers with the current multiplex PCR and were only DON producers by chemical analysis.     

Determination of Deoxynivalenol and Nivalenol in Wheat by Ultra-Performance Liquid Chromatography/Photodiode-Array Detector and Immunoaffinity Column Cleanup

An ultra-performance liquid chromatography (UPLC®) method has been developed for the simultaneous determination of deoxynivalenol (DON) and nivalenol (NIV) in wheat. Ground sample was extracted with water and the filtered extract was cleaned up through an immunoaffinity column containing a monoclonal antibody specific for DON and NIV. Toxins were separated and quantified by UPLC® with photodiode-array detector (λ?=?220 nm) in less than 3 min. Mean recoveries from blank wheat samples spiked with DON and NIV at levels of 100–2,000 μg/kg (each toxin) ranged from 85 to 95 % for DON and from 81 to 88 % for NIV, with relative standard deviations less than 7 %. Similar recoveries were observed from spiked samples when methanol/water (80:20, v/v) was used as extraction solvent. However, by using a wheat sample naturally contaminated with DON and NIV, the one-way analysis of variance (Student–Newman–Keuls test) between different extraction solvents and modes showed that water extraction provided a significant increase (P?<?0.001) in toxin concentrations (mean values of six replicate analyses) with respect to methanol/water (80:20, v/v). No significant difference was observed between shaking (60 min) and blending (3 min). The limit of detection (LOD) of the method was 30 μg/kg for DON and 20 μg/kg for NIV (signal-to-noise ratio 3:1). The immunoaffinity columns showed saturation of DON/NIV binding sites at levels higher than 2,000 ng in blank wheat extracts spiked with the corresponding amount of mycotoxin, as single mycotoxin or sum of DON and NIV. The range of applicability of the method was from LOD to 4,000 μg/kg, as single mycotoxin or sum of DON and NIV in wheat. The analyses of 20 naturally contaminated wheat samples showed DON contamination in all analyzed samples at level ranging from 30 to 2,700 μg/kg. NIV was detected in two samples at negligible toxin levels (up to 46 μg/kg). This is the first UPLC® method using immunoaffinity column cleanup for the simultaneous and sensitive determination of DON and NIV in wheat.     

Simple validated method for simultaneous determination of deoxynivalenol,nivalenol, and their 3-β-D-glucosides in baby formula and Korean rice wine via HPLC-UV with immunoaffinity cleanup

A simple and reliable method for the simultaneous determination of major type B trichothecene mycotoxins, deoxynivalenol (DON) and nivalenol (NIV), along with their 3-β-d-glucosides (DON-3-glucoside (DON3G) and NIV-3-glucoside (NIV3G)) in baby formula and Korean rice wine was validated in the present study. The method was based on immunoaffinity cleanup followed by analysis using an HPLC-UV technique. The method was validated in-house for two matrices as follows: linearity (R² > 0.99) was established in the range of 20–1000 μg kg^–1; accuracy (expressed as recovery) ranged from 78.7 to 106.5% for all the analytes; good intermediate precision (relative standard deviation < 12%), and adequate detection and quantitation limits (< 4.4 and < 13.3 μg kg^–1, respectively) were achieved. Furthermore, the estimated measurement expanded uncertainty was determined to be 4–24%. The validated method was successfully applied to the analysis of 31 baby formulas and Korean rice wines marketed in Korea.