A rapid UHPLC-MS/MS screening method for the detection of the addition of porcine blood plasma to emulsion-type pork sausages.

The adulteration of meat products by the undeclared addition of commercially available blood plasma powder is quite conceivable due to low costs, high protein contents (about 70%), and advantageous functional properties. This applies particularly to pork, which has the highest meat production rate in the European Union. Evidence of this type of food fraud has been rather difficult to identify due to the lack of appropriate analytical methods, especially when adding plasma to meat of the same animal species. Consequently, a rapid UHPLC-MS/MS method for the detection of porcine blood plasma in emulsion-type pork sausages was developed. After protein extraction and tryptic digestion in a quick and simple one-pot process, species-specific marker peptides for porcine blood cell proteins (four markers) and plasma proteins (12 markers) were measured by UHPLC-MS/MS. Emulsion-type pork sausages were produced from a variety of raw materials that differed in the age or sex of the slaughtered pigs. Sausages were spiked with 0.5, 1, 1.5, 2, 3, or 5% meat substitution by one of two plasma powders, or produced as corresponding blank samples, and subjected to different thermal treatments as full or semi-preserves. Four plasma peptides were identified for the overall sample that allowed detection down to 0.7% meat substitution from the sum of their peak areas, with 5% error probability for both false positives and negatives.

Environmental PAH analysis by gas chromatography-atmospheric pressure laser ionization-time-of-flight-mass spectrometry (GC-APLI-MS).

The application of polycyclic aromatic hydrocarbon (PAH) analysis by gas chromatography coupled with atmospheric pressure laser ionization and mass spectrometry (GC-APLI-MS) to environmental samples was investigated in the study. The limit of detection for 40 PAH in a standard mixture was 5-100 fg, demonstrating GC-APLI-MS to be a highly sensitive technique and more sensitive by a factor of 100-3,500 compared to GC-MS. Acenaphthylene and cyclopenta[cd]pyrene were not detectable <2,500 fg per injection. To make use of this very high PAH sensitivity, the technique was applied to samples of environmental interest with limited available sample amounts such as particulate matter (PM), soot and a sample from a bioaccumulation test with Lumbriculus variegatus. First, special sample preparation was necessary and ultrasonic extraction proved to be suitable, if a thorough clean-up was performed and plastic materials avoided. By GC-APLI-MS and GC-MS, 224 and 28 single PAH compounds were detected in PM, about 1,000 and 15 in birch soot, and 9 and 2 in worm tissue, respectively, revealing the enormous potential of the method. The selectivity of GC-APLI-MS was shown for a crude oil where >2,200 PAH were detected without any sample preparation.