[Using mass spectrometry as a tool for testing for toxic substances in foods: toward food safety]

A large number of toxic substances, such as pesticides, antibiotics and toxins from different sources (natural or man-made) and different degrees of toxicity for human health can be found in foods. This type of compounds are generally found at very low concentrations in highly complex matrices, it therefore being necessary for the most highly reliable methodologies possible to be sued. In this regard, the use of gas and liquid chromatography techniques coupled to mass spectrometry detectors has made it possible to properly detect this type of substances in foods at extremely low concentrations. Therefore, depending upon the characteristics of the contaminant, one must select the chromatography technique which affords the possibility of best separating the contaminant from the interfering substances present in the matrix, as well as from the contaminants amongst one another. This methodology provides highly valuable data enhancing our knowledge of public health through food safety.