In number of foodborne outbreaks S. aureus intoxications stand highly ranked next to those caused by other pathogens like Bacillus cereus, Escherichia coli, Salmonella enterica and others. In number of outbreaks and human cases per causative agent in strong evidence food-borne outbreaks in the EU, bacterial toxins share the second place together with foodborne viruses. Among bacterial toxins, staphylococcal enterotoxins (SEs) was by far the most important etiological agent. The largest proportion of strong evidence outbreaks caused by staphylococcal toxins was attributed to mixed or buffet meals (28.9%), followed by cheese (18.4%). This indicates that milk, milk derived products and ready-to-eat (RTI) foods require attention in detecting and quantifying SEs. We developed and are validating method to specifically quantify SEs in pork meat using stable isotope dilution and UPLC–MSMS analysis. Pork meat was spiked with SEA and/or SEB. Next we extract the SEs from the meat using isoelectric point precipitation and ultrafiltration. Afterwards the sample was overnight digested with trypsin to obtain SE-derived peptides. Only the endogenous peptides that are unique to their respective SE are selected for analysis with LC–MSMS. Additionally all samples are spiked with internal standards (IS). These IS are isotopically labelled equivalents of the unique endogenous tryptic peptides and show the same chemical behavior as the endogenous peptides. Both the endogenous peptide and its respective IS should elute from the column at the same retention time, assuring high specificity of the method. The sample is then injected and analysed using online Solid Phase Extraction (SPE) –UPLC–MS/MS. Analytes of interest are trapped on the SPE-column, while e.g. interfering salts are flushed to the waste. Afterwards, the peptides are back-flushed from the SPE-column onto the analytical column where the separation occurs. The MS/MS is programmed to search for the parent-daughter mass transition for each unique endogenous peptide and IS. These parent-daughter transitions are unique for each peptide and can be used to detect the SEs very specifically. We are currently validating this method according to ISO 2002/657/EC. When comparing the MS spectra peaks found for the IS and the endogenous peptides we were able to identify and quantify the presence of SEA and/or SEB in the spiked meat. We are in the process of method validation where we will determine linearity, matrix effect, repeatability, trueness, recovery, LOD and LOQ of the method. We developed and are validating method to specifically detect SEs in pork meat. This method could be used to quantify SEs in food poisoning once the presence of S. aureus is proven or it could also be used (in parallel with current immunologic methods) to directly confirm and quantify SEs. Currently, only SEA and SEB are identified and quantified, but the method will be