Mycotoxin analysis is usually carried out by high performance liquid chromatography after immunoaffinity column cleanup or in enzyme-linked immunosorbent assay tests. These methods normally involve determination of single compounds only. EU legislation already exists for the aflatoxins, ochratoxin A and patulin in food, and legislation will come into force for deoxynivalenol, zearalenone and the fumonisins in 2007. To enforce the various legal limits, it would be preferable to determine all mycotoxins by routine analysis in different types of matrices in one single extract. This would also be advantageous for HACCP control purposes. For this reason, a multi-method was developed with which 33 mycotoxins in various products could be analysed simultaneously. The mycotoxins were extracted with an acetonitrile/water mixture, diluted with water and then directly injected into a LC-MS/MS system. The mycotoxins were separated by reversed-phase HPLC and detected using an electrospray ionisation interface (ESI) and tandem MS, using MRM in the positive ion mode, to increase specificity for quality control. The following mycotoxins could be analysed in a single 30-min run: Aflatoxins B1, B2, G1 and G2, ochratoxin A, deoxynivalenol, zearalenone, T-2 toxin, HT-2 toxin, alpha-zearalenol, alpha-zearalanol, beta-zearalanol, sterigmatocystin, cyclopiazonic acid, penicillic acid, fumonisins B1, B2 and B3, diacetoxyscirpenol, 3- and 15-acetyl-deoxynivalenol, zearalanone, ergotamin, ergocornin, ergocristin, alpha-ergocryptin, citrinin, roquefortin C, fusarenone X, nivalenol, mycophenolic acid, alternariol and alternariol monomethyl ether. The limit of quantification for the aflatoxins and ochratoxin A was 1.0 microg kg(-1) and for deoxynivalenol 50 microg kg(-1). The quantification limits for the other mycotoxins were in the range 10-200 microg kg(-1). The matrix effect and validation data are presented for between 13 and 24 mycotoxins in peanuts, pistachios, wheat, maize, cornflakes, raisins and figs. The method has been compared with the official EU method for the determination of aflatoxins in food and relevant FAPAS rounds. The multi-mycotoxin method has been proven by the detection of more than one mycotoxin in maize, buckwheat, figs and nuts. The LC-MS/MS technique has also been applied to baby food, which is subject to lower limits for aflatoxin B1 and ochratoxin A, ergot alkaloids in naturally contaminated rye and freeze-dried silage samples.

A survey was conducted to determine the occurrence of mycotoxins in feedstuffs of dairy cows in the Netherlands and to estimate total dietary intakes of these compounds. Twenty-four dairy farms were visited twice and samples taken of all diet ingredients. Feed intake data were collected by means of questionnaires. A total of 169 feed samples were collected and analyzed for 20 mycotoxins using a liquid chromatography tandem mass spectrometry multimethod. Silage and compound feed were the main diet ingredients, representing on average 67 and 23% of dry matter intake, respectively. Deoxynivalenol (DON), zearalenone, roquefortine C, and mycophenolic acid were the mycotoxins with the highest incidence. The incidence of DON in silage, compound feed, and feed commodity samples was 38 to 54%. The incidence of zearalenone in silage, compound feed, and feed commodity samples was 17 to 38%. The DON and zearalenone had a low incidence in forage samples and were not detected in ensiled by-product samples. Roquefortine C and mycophenolic acid were only detected in silage and ensiled by-product samples (incidence 7 to 19%). Fumonisins B(1) and B(2) were detected in 2 compound feed samples and one feed commodity sample. Aflatoxins B(1), B(2), G(1), and G(2), ochratoxin A, T-2 and HT-2 toxin, 3-acetyl-DON, 15-acetyl-DON, diacetoxyscirpenol, sterigmatocystin, fusarenon-X, ergotamine, and penicillinic acid were not detected in any of the samples. Average concentrations of DON, zearalenone, roquefortine C, and mycophenolic acid in complete diets were 273, 28, 114, and 54 microg/kg, respectively. Maximum concentrations were 969, 203, 2,211, and 1,840 microg/kg, respectively. Calculated average daily intakes of these mycotoxins were 5.0, 0.5, 2.0, and 0.9 mg/animal, respectively, and maximum daily intakes 19.3, 3.5, 38.9, and 32.3 mg/animal, respectively. Corn silage was the major source of all 4 of these mycotoxins in the diet. Extremely high concentrations of roquefortine C and mycophenolic acid (up to 45 and 25 mg/kg, respectively) were detected in visibly molded areas in surface layers of corn silage. These areas appeared to be the main source of roquefortine C and mycophenolic acid in the diet. Because carry-over of DON, zearale-none, roquefortine C, and mycophenolic acid into milk is negligible, their occurrence in feedstuffs is not considered of significant concern with respect to the safety of dairy products for consumers. Potential implications for animal health are discussed.

The occurrence of mycotoxins in 140 maize silages, 120 grass silages and 30 wheat silages produced in the Netherlands between 2002 and 2004 was determined using a liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) multi-method. Deoxynivalenol (DON) was detected above the limit of quantification (LOQ) of 250 μg kg⁻¹ in 72% of maize and 10% of wheat silages. Average DON concentrations were 854 and 621 μg kg⁻¹, respectively, and maximum concentrations 3142 and 1165 μg kg⁻¹, respectively. Zearalenone was detected above the LOQ of 25 μg kg⁻¹ in 49% of maize and 6% of grass silages. Average zearalenone concentrations were 174 and 93 μg kg⁻¹, respectively, and maximum concentrations 943 and 308 μg kg⁻¹, respectively. The incidences and average concentrations of DON and zearalenone in maize silage were highest in 2004. The incidence of other mycotoxins was low: fumonisin B1 and 15-acetyl-DON were detected in 1.4 and 5% of maize silages, respectively, and roquefortin C in 0.8% of grass silages. None of the silages contained aflatoxins, ochratoxin A, T2-toxin, HT2-toxin, sterigmatocystin, diacetoxyscirpenol, fusarenon-X, ergotamine, penicillinic acid, or mycophenolic acid. This study demonstrates that maize silage is an important source of DON and zearalenone in the diet of dairy cattle. Since the carryover of these mycotoxins into milk is negligible, their occurrence in feed is not considered to be of significant concern with respect to the safety of dairy products for consumers. Potential implications for animal health are discussed.

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A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for the determination of aflatoxin B1 and total aflatoxins at European regulatory limits. The test portion is extracted with methanol–water (8 + 2) for dried figs and paprika, and with methanol–water (8 + 2) plus hexane (or cyclohexane) for peanut butter and pistachios. The sample extract is filtered, diluted with phosphate buffer saline, and applied to an immunoaffinity column. The column is washed with water and the aflatoxins are eluted with methanol. Aflatoxins are quantitated by reversed-phase LC with post-column derivatization (PCD) involving bromination. PCD is achieved with either an electrochemical cell (Kobra cell) and addition of bromide to the mobile phase or pyridinium hydrobromide perbromide. Determination is by fluorescence. Peanut butter, pistachio paste, dried fig paste, and paprika powder samples, both naturally contaminated with aflatoxins and containing added aflatoxins, were sent to 16 collaborators in 16 European countries. Test portions of samples were spiked at levels of 2.4 and 9.6 ng/g for total aflatoxins which included 1.0 and 4.0 ng/g aflatoxin B1, respectively. Recoveries for total aflatoxins ranged from 71 to 92% with corresponding recoveries for aflatoxin B1 of 82 to 109%. Based on results for spiked samples (blind duplicates at 2 levels) as well as naturally contaminated samples (blind duplicates at 4 levels, including blank), the relative standard deviation for repeatability ranged from 4.6 to 23.3% for total aflatoxins and from 3.1 to 20.0% for aflatoxin B1. The relative standard deviation for reproducibility ranged from 14.1 to 34.2% for total aflatoxins, and from 9.1 to 32.2% for aflatoxin B1. The method showed acceptable within-laboratory and between-laboratory precision for all 4 matrixes, as evidenced by HORRAT values <1, at the low levels of determination for both total aflatoxins and aflatoxin B1.