Mycotoxins technique

Volume 54 Chromatography of Mycotoxins. Techniques and Applications edited by V. Betina... 

Betina V (1993) In Betina V (ed.) Chromatography of Mycotoxins Techniques and Application, pp. 141-233. Amsterdam Elsevier. 

Scott PM (1993) Gas chromatography of mycotoxins. In Betina V (ed) Chromatography of mycotoxins, techniques and applications. Elsevier, Amstiadam... 

Mycotoxins, toxic metaboUtes of some fungi, can be assayed by immunochemical techniques to determine concentration in animal feed and foodstuffs. Some of the analytes assayed in kits and the detection limits are Hsted in Table 4 (45). These assays are especially advantageous for routine analysis of large samples of foodstuffs (45,46). 

Krska R (1998) Performance of modern sample preparation technique in the analysis of Fusarium mycotoxins in cereals. J Chromatogr A 815 49-57 Krska R, Josephs R (2001) The state-of-the-art in the analysis of estrogenic mycotoxins in cereals. J Anal Chem 369 469-476... 

Enzyme-linked immunosorbent assay (ELISA) is a very useful technique for the specific and sensitive assay of certain compounds, in which suitable antibodies, monoclonal or polyclonal, to the compounds are available. The technique has found particular application m the monitoring of environmental contaminants and toxins, either studying the primarily contaminated materials, e.g., foodstuffs, or body fluids of potentially exposed humans. The technique has been increasingly applied to monitoring the carcinogenic mycotoxins, the aflatoxins. 

As far as the mycotoxin analysis based on HPLC techniques is concerned, most methods include the following steps. 

DR Lauren, MA Ringrose. Determination of the fate of three Fusarium mycotoxins through wetmilling of maize using an improved HPLC analytical technique. Food Add Contam 14(5) 435-443, 1997. 

This paper shows a nice example for solving an important analytical problem using MISPE. Mycotoxins and particularly zearalenone (ZON) and /nmv-a-zearalenol (a-ZOL) present an everyday problem in food analysis. Existing sample clean-up techniques have different drawbacks. Liquid-liquid extraction is characterized by... 

Various techniques used for the determination of mycotoxins are reviewed below. 

Kalinoski et al. [32] has applied this method to the determination of tri-chothecene mycotoxins in wheat. The methods were based on chemical ionisation MS and collision-induced dissociation tandem MS and enabled the rapid identification of ppm levels of several trichothecene mycotoxins. Supercritical carbon dioxide is shown to allow identification of mycotoxins with minimum sample handling in complex natural matrices such as wheat. Tandem MS techniques are employed for unambiguous identification of compounds of varying polarity, and false positives from isobaric compounds are avoided. Capillary column SCFC-MS of a SCF extract of the same sample was also performed, and detection limits in the ppb range appear feasible. 

Immunoassay methodologies are now a major method for rapid analysis of many mycotoxins, especially aflatoxins. These immunochemical techniques are based upon quite different principles to chromatographic procedures. In essence, immunochemical procedures involve reversible binding between antigens (the... 

Since most mycotoxins in agricultural materials are usually contained in a very small proportion of individual seeds or kernels the most practical and effective method of reducing the mycotoxin content of the whole commodity is to remove the contaminated seeds or kernels mechanically (West and Bullerman, 1991). Various techniques have been devised, based on colour and visual appearance of decay or damage to separate out contaminated seed etc. This may be manual or by more advanced electronic instrumental selection. 

Fluorescence may by induced using labeled mono- or polyclonal antibodies raised against the compound of interest. This technique has been used successfully to detect the presence of okadaic acid in cultures of Prorocentrum lima, and, further, to estimate quantities of the compound in individual cells.110 Immunofluoresence in combination with thin layer chromatography and ELISA techniques have also been used to detect multiple haptens in mycotoxin families.111112... 

Coker RD Design of sampling plans for determination of mycotoxin in food and feed in Sinha KK, Bhatnagar D (eds) Mycotoxin in Agriculture and Food Safety. New York, Dekker, 1998, pp 109-134. Wilson DM, Sydenham EW, Lombaert GA, Trucksess MW, Abramson D, Bennett GA Mycotoxin analytical techniques in Sinha KK, Bhatnagar D (eds) Mycotoxin in Agriculture and Food Safety. New York, Dekker, 1998, pp 135-182. 

AC1470) with linked-scan techniques to demonstrate the stereochemical effects regulating the fragmentation pattern in trichothecene mycotoxins (84TH2 87UP4). These data were correlated to those obtained by X-ray diffraction (84MI3). 

Thin-layer chromatography (TLC) is a widely used analytical technique for many investigative purposes. Detection of mycotoxins by means of TLC has been in use for many years. Official methods of analysis often rely on these techniques for both identification and quantification of several mycotoxins [1]. 

Detection may be based on several techniques older systems used postelution derivatization [8] and observation of colored spots. It is more common now to use either ultraviolet (UV) [5] or even fluorescence [3,4] because these techniques allow quantification of mycotoxin residues. More complex systems have been tested (computer imaging [7]) for particular applications, but these techniques are not applied to routine analysis of plants. 

More and more, however, quantitative analysis can be performed by means of scanners (UV, fluorescence), and HPTLC does not need to be completed by another analytical technique for the precise determination of residues. Today, most official methods of analysis for the detection of mycotoxins in foods are based on TLC technology. 

An improved procedure for the production of the tremorgenic mycotoxins trypto-quivaline and tryptoquivalone by Aspergillus clavatus, has been reported this makes use of pearled barley in a procedure based on Hesseltine s solid substrate fermentation technique. 

Ozay, G., Aran, N., and Pala, M. 1995. Influence of harvesting and drying techniques on microflora and mycotoxin contamination of figs. Nahrung 39, 156-165. 

---