Development and validation of a liquid chromatography/tandem mass spectrometric method for the determination of 39 mycotoxins in wheat and maize. Rapid Commun Mass Spectrom 20: 2649
ABSTRACT This paper describes the first validated method for the determination of 39 mycotoxins in wheat and maize using a single extraction step followed by liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (LC/ESI-MS/MS) without the need for any clean-up. The 39 analytes included A- and B-trichothecenes (including deoxynivalenol-3-glucoside), zearalenone and related derivatives, fumonisins, enniatins, ergot alkaloids, ochratoxins, aflatoxins and moniliformin. The large number and the chemical diversity of the analytes required the application of the positive as well as the negative ion ESI mode in two consecutive chromatographic runs of 21 min each. The solvent mixture acetonitrile/water/acetic acid 79 + 20 + 1 (v/v/v) has been determined as the best compromise for the extraction of the analytes from wheat and maize. Raw extracts were diluted 1 + 1 and were injected without any clean-up. Ion-suppression effects due to co-eluting matrix components were negligible in the case of wheat, whereas significant signal suppression for 12 analytes was observed in maize, causing purely proportional systematic errors. Method performance characteristics were determined after spiking blank samples on multiple levels in triplicate. Coefficients of variation of the overall process of <5.1% and <3.0% were obtained for wheat and maize, respectively, from linear calibration data. Limits of detection ranged from 0.03 to 220 microg/kg. Apparent recoveries (including both the recoveries of the extraction step and matrix effects) were within the range of 100 +/- 10% for approximately half of the analytes. In extreme cases the apparent recoveries dropped to about 20%, but this could be compensated for to a large extent by the application of matrix-matched standards to correct for matrix-induced signal suppression, as only a few analytes such as nivalenol and the fumonisins exhibited incomplete extraction. For deoxynivalenol and zearalenone, the trueness of the method was confirmed through the analysis of certified reference materials.
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- "All mycotoxins were best detected in positive mode. Although the addition of 5 mM ammonium acetate to the eluents should suppress the formation of stable sodium adducts (Sulyok et al., 2006), stable alkali ions could be formed due to the presence of traces of alkali ions coming from the sample preparation. In this study, the ions with the highest intensities detected were [MþNa] þ ions for DON, AFB 1 , AFB 2 , AFG 1 and AFG 2 ; [MþH] þ for FB 1 , OTA, ZEN and FB 2 , and [MþNH 4 ] þ for HT-2 and T-2 toxins. "
ABSTRACT: In this study, the co-occurrence of multiple mycotoxins in maize kernels collected from 300 households' stores in three agro-ecological zones in Tanzania was evaluated by using ultra high performance liquid chromatography/time-of-flight mass spectrometry (TOFMS) with a QuEChERS-based procedure as sample treatment. This method was validated for the analysis of the main eleven mycotoxins of health concern that can occur in maize: aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), ochratoxin A (OTA), deoxynivalenol (DON), fumonisin B1 (FB1), fumonisin B2 (FB2), HT-2 toxin, T-2 toxin and zearalenone (ZEN). From each zone one major maize producing district for home consumption was chosen and 20 villages for each district were randomly selected for sampling. All mycotoxins of health concern, except for T-2 toxin, were detected in the maize samples. Particularly high levels of AFB1 (50%; 3–1,081 μg kg−1), FB1 (73%; 16–18,184 μg kg−1), FB2 (48%; 178–38,217 μg kg−1) and DON (63%; 68–2,196 μg kg−1) were observed. Some samples exceeded the maximum limits set in Tanzania for aflatoxins or in European regulations for other mycotoxins in unprocessed maize. Eighty seven percent of samples were contaminated with more than one mycotoxin, with 45% of samples co-contaminated by carcinogenic mycotoxins, aflatoxins and fumonisins. Significant differences in contamination pattern were observed among the three agro-ecological zones. The high incidence and at high levels (for some) of these mycotoxins in maize may have serious implications on the health of the consumers since maize constitute the staple food of most Tanzanian population. Effective strategies targeting more than one mycotoxin are encouraged to reduce contamination of maize with mycotoxins.Food Control 08/2015; 54. DOI:10.1016/j.foodcont.2015.02.002 · 2.81 Impact Factor
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- "Because of that, various solvents have been used to extract fumonisins from maize products and matrices other than maize, and these were MeOH–water and ACN–water mixtures , phosphate buffer (PB, Trucksess et al. 2000; Kulisek and Hazebroek 2000), borate buffer (Scott and Lawrence 1994), 0.1 M HCl (Meister 1999), ethanol (Lawrence et al. 2000), and additives such as ethylenediaminetetraacetic acid disodium salt and enzymes (Kim et al. 2002), etc. Besides the composition of the extraction solvent, the temperature and dynamics of homogenization have a considerable influence on the efficiency of the extraction of fumonisins from various matrices (Rice et al. 1995; Meister 1999; Scott et al. 1999; Lawrence et al. 2000; Kulisek and Hazebroek 2000; Kim et al. 2002; Sulyok et al. 2006; Pietri and Bertuzzi 2012). A number of comparative studies aiming at the improvement of the extraction of fumonisins demonstrated that there is no universal procedure applicable to all types of samples. "
ABSTRACT: The methods for the determination of fumonisins encompass several essential steps that are of great importance for obtaining accurate and reliable results. Extraction, as the first step in the sample preparation, is crucial for a satisfactory recovery. In this study, extraction methods without organic solvents were applied for the quantification of fumonisins B1 (FB1), B2 (FB2), and B3 (FB3) by high-performance liquid chromatography (HPLC) with fluorescence detector (FLD) and of total fumonisins by enzyme-linked immunosorbent assay (ELISA). The recoveries of the HPLC–FLD determination of two reference materials after extraction with distilled water were 99 ± 5.6 and 86 ± 3.9 % for FB1, and 111 ± 5 and 81 ± 1 % for FB2, while the extraction with phosphate buffer (PB) resulted in the recoveries of 104 ± 20.2 and 92 ± 8.6 %; for FB1 and 149 ± 13 and 100 ± 5.8 % for FB2. For FB3, the recovery with distilled water was 118 ± 0.5 % and with PB 131 ± 8.8 %. Two ELISA methods gave the following recoveries for total fumonisins: 100 ± 0.6 and 133 ± 0.7 % after the extraction with distilled water and 92 ± 2.2 and 123 ± 5.4 % with PB. The limits of detection and quantification using inorganic solvents and the HPLC–FLD method were at the level of micrograms per kilogram for all fumonisins, and somewhat higher than those obtained using organic extraction methods. The determination of individual and total fumonisins in the reference material by applying extraction with inorganic solvents revealed no significant difference (p > 0.05) as compared to the AOAC method and methods recommended by ELISA manufacturers. Generally, the extraction using inorganic solvents proved to be very effective for all the types of real, naturally contaminated samples.Food Analytical Methods 06/2015; 8(6):1446-1455. DOI:10.1007/s12161-014-0030-5 · 1.96 Impact Factor
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- "Mycotoxins are chemically diverse substances, ranging from very polar (e.g., moniliformin, nivalenol) to nonpolar (e.g., beauvericin, enniatins), while their solubility in liquid solvents also varies extensively. Typically acidified mixture of water with organic solvents such as methanol, acetone, or acetonitrile are used to extract a large amount of different toxins within a single procedure (Sulyok et al., 2006). It should be noted that the extraction of a multitude of different compounds with a single solvent mixture has to be a compromise as better suited solvents are available for the determination of single analytes. "
ABSTRACT: Extensive research over the last couple of decades has made it obvious that mycotoxins are commonly prevalent in majority of feed ingredients. A worldwide mycotoxin survey in 2013 revealed 81% of around 3,000 grain and feed samples analyzed had at least 1 mycotoxin, which was higher than the 10-year average (from 2004 to 2013) of 76% in a total of 25,944 samples. The considerable increase in the number of positive samples in 2013 may be due to the improvements in detection methods and their sensitivity. The recently developed liquid chromatography coupled to (tandem) mass spectrometry allows the inclusion of a high number of analytes and is the most selective, sensitive, and accurate of all the mycotoxin analytical methods. Mycotoxins can affect the animals either individually or additively in the presence of more than 1 mycotoxin, and may affect various organs such as gastrointestinal tract, liver, and immune system, essentially resulting in reduced productivity of the birds and mortality in extreme cases. While the use of mycotoxin binding agents has been a commonly used counteracting strategy, considering the great diversity in the chemical structures of mycotoxins, it is very obvious that there is no single method that can be used to deactivate mycotoxins in feed. Therefore, different strategies have to be combined in order to specifically target individual mycotoxins without impacting the quality of feed. Enzymatic or microbial detoxification, referred to as "biotransformation" or "biodetoxification," utilizes microorganisms or purified enzymes thereof to catabolize the entire mycotoxin or transform or cleave it to less or non-toxic compounds. However, the awareness on the prevalence of mycotoxins, available modern techniques to analyze them, the effects of mycotoxicoses, and the recent developments in the ways to safely eliminate the mycotoxins from the feed are very minimal among the producers. This symposium review paper comprehensively discusses the above mentioned aspects. © The Author 2015. Published by Oxford University Press on behalf of Poultry Science Association.Poultry Science 04/2015; 94(6). DOI:10.3382/ps/pev075 · 1.67 Impact Factor