Ochratoxin analysis

Bilchmann N B and Hald B (1985), Analysis, occurrence and control of ochratoxin A residues in Danish pig kidneys , Food Addit. Contam., 2, 193-199. 

Farber, P., and Geisen, R. (2004). Analysis of differentially-expressed ochratoxin A biosynthesis genes in Penicillium nordicum. Eur. J. Plant Pathol. 110, 661-669. 

During the analysis, a flask containing a 5% aqueous solution of sodium hypochlorite should be kept near the bench, in case of emergency. The issue of safety precautions has been studied rather extensively for aflatoxins (21), ochratoxin A, citrinin, sterigmatocystin, and pat-ulin (22). 

Confirmation by LC-MS This method is not used much, since it involves expensive apparatus, and rather good experience in the technique is needed. Abramson (66) illustrated the advantages resulting from the combination of liquid chromatography and mass spectrometry for ochratoxin A in barley. Among the types of interfaces most used for ochratoxin A analysis were thermospray, direct liquid induction (DLI), and... 

Analysis is usually based on foods and feeds (cereals, etc.). In swine, for instance, an epidemiological study conducted on feed samples detected ochratoxin (mean 58.3 (xg/kg) and zearalenon (mean 30.3 xg/kg) in corn. These concentrations were associated with respiratory disorders and also infertility... 

Castellari, M., Fabbri, S., Fabiani, A., Amati, A. and Galassi, S. (2000) Comparison of different immunoaffinity clean-up procedures for high-performance liquid chromatographic analysis of ochratoxin A in wines,/. Chromatogr. A, 888(1-2), 129-136. 

Flamini, R., Dalla Vedova, A., De Rosso, M. and Panighel, A. (2007) A New Sensitive and Selective Method for Analysis of Ochratoxin A in Grape and Wine by direct liquid chromatography/surface activated chemical ionization-tandem mass spectrometry, Rapid Commun. Mass Spectrom. 21(22), 3737-3742. 

International Organization of Vine and Wine, Measuring ochratoxin A in wine after going through an immunoaffinity column and HPLC with fluorescence detection, Compendium of International Methods of Wine and Must Analysis Vol. 2 (2006). 

Saez, J.M., Medina, A., Gimeno-Adelantado, J.V., Mateo, R. and Jimenez, M. (2004) Comparison of different sample treatments for the analysis of ochratoxin A in must, wine and beer by liquid chromatography,/. Chromatogr. A, 1029 (1-2), 125-133. 

Belli, N., Marin, S., Sanchis, V., and Ramos, AJ. 2002. Ochratoxin A (OTA) in wines, musts and grape juices Occurrence, regulations and methods of analysis. Food Sci. Technol. Int. 8, 325-335. 

Cholmakov-Bodechtel, C., Wolff, J., Gareis, M., Bresch, H., Engel, G., Majerus, P., Rosner, H., and Schneider, R. 2000. Ochratoxin A Representative food consumption survey and epidemiological analysis. Arch. Lebensmittelhyg. 51, 111-115. 

Northern blot analysis indicates a strong expression of another member ofthe OAT family, rOat3 [75]. It transports substrates such as paru-aminohippuric acid, estrone-3-sulfate, or ochratoxin, not taurocholate or digoxin [75], and it also recognizes cationic cimetidine. Human hOAT3 seems to be expressed rather in the kidney than in the liver [76]. 

Figure 8.4. The SACI/MS3 spectra of the OTA daughter ion at m/z 358 (above) and of the ZAN daughter ion at m/z 303 (below). The OTA m/z 239+341 and ZAN m/z 163+189+207 signals are used for quantitative analysis. (Spectra acquired in positive-ion mode collision energy applied to the parent ion 80% of maximum value MS3 of daughter ions at 100% of maximum collision energy). (Reprinted from Rapid Communications in Mass Spectrometry 21,Flamini et al., A new sensitive and selective method for analysis of ochratoxin A in grape and wine by direct liquid chromato-graphy/surface activated chemical ionization-tandem mass spectrometry, p. 3740, Copyright 2007, with permission from John Wiley Sons, Ltd.)...

The quantification of ochratoxin A, at levels within the range 0.25-10 ng/ml from wine by HPLC-fluorescence detection, was described [193]. RP-HPLC - fluorescence method for the detection of ochratoxin A in wine with a detection limit of 0.05 ng/ml was also published [194]. A stable isotope dilution assay by LC-MS/MS was developed for quantification of the ochratoxin A by using [D5]-ochratoxin A as internal standard with a low detection and quantification limits of 0.5 and 1.4 pg/kg, respectively [195]. The LC-MS/MS method (ESI and APCI) was also applied to the analysis of contaminated coffee samples by ochratoxins A and B with absolute minimum detection limit around 10-20 pg per injection. Fragment ions from the [M+H]+ and [M+Na]+ ions of... 

K. Hult, R. Fuchs, M. Peraica, R. Plestina, and S. Ceovic, Screening for Ochratoxin A in Blood by Flow Injection Analysis. J. Appl. Toxicol., 4 (1984) 326. 

The major analyte in human blood serum was the parent compound, and only small concentrations of ochratoxin A metabolites and/or conjugates could be measured. In contrast, analysis of urine samples indicated that only about 50% of the radioactivity in the urine was parent ochratoxin A, suggesting the presence of ochratoxin A metabolites (particularly ochratoxin alpha) and/or ochratoxin A-glucuronic acid conjugates (Studer-Rohr et al., 2000). 

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