Levels of ochratoxin A in wheat and maize bread from the central zone of Portugal.
Ochratoxigenic fungi are natural contaminants of cereal and the produced toxins are harmful to humans and animals. Ochratoxin A (OTA) is among the most important mycotoxins, and the International Agency for Research on Cancer (IARC) classifies it as possibly carcinogenic to humans (group 2B). A total of 61 samples of bread from the central zone of Portugal were analysed for OTA by liquid chromatography (LC) with fluorescence detection (FD). For confirmation two procedures were applied, methyl ester derivatization with boron trifluoride-methanol and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS). As far as we know, this is the first report where on-line…
Determination of macrolide and lincosamide antibiotics by pressurised liquid extraction and liquid chromatography-tandem mass spectrometry in meat and milk
Abstract A total of 155 samples, including meat and milk, were analyzed using a method developed for determining five macrolide antibiotics: tilmicosin (TILM), tylosin (TS), spiramycin (SPM), erythromycin (ERY), and tulathromycin (TULA) and two lincosamide antibiotics: pirlimycin (PIRL) and lincomycin (LM). The method was performed by pressurised liquid extraction (PLE) coupled to LC–MS/MS using electrospray ionization in positive ion mode. 2.5 mL of milk or 2.5 g of meat were dispersed in ethylenediaminetetraacetic acid sodium salt 2-hydrate (EDTA) and sea sand. The PLE conditions as: solvent, temperature, pressure, static time, and cell size were optimized. The following analytical parame…
Determination of ochratoxin A in organic and non-organic cereals and cereal products from Spain and Portugal
The objective of this work was to know the occurrence of OTA in organic and non-organic cereals and cereal products from Spain and Portugal. A method based on extraction with matrix solid phase dispersion (MSPD) using octylsilica (C8) followed by liquid chromatography coupled with fluorescence detection (LC-FD) was used to determine OTA from the selected samples. Recoveries of OTA from the studied samples spiked at 10 ng/g level ranged from 78% to 89% with a standard deviation of 3.66. The limits of detection and quantification of this method were 0.05 and 0.19 ng/g, respectively. Furthermore, LC-FD after OTA methylation was used to confirm the identity of OTA in all positive samples. This …