Simultaneous Determination of Animal Products from Ruminant, Pig, Poultry, and Fish in Feedingstuff by Targeted High-Resolution LC–MS/MS

The prohibition of processed animal proteins (PAPs) has
been relaxed
gradually since 2007. The official control method for PAPs in feedingstuff,
a combination of light microscopy (LM) followed by PCR, is no longer
sufficient. Thus, a targeted LC–MS/MS method was developed,
which enables a tissue-specific distinction between egg and dairy
products, gelatine, and PAPs derived from blood or muscle tissue of
the species ruminants, pigs, poultry, and fish. Tissue-specific proteins
were analyzed after tryptic digestion to peptides with high-resolution
ESI-QTOF-MS. A targeted method was developed based on untargeted proteomics
approaches and the selection of specific peptides (45 unique peptides
in total). Proficiency testing of blank and spiked samples revealed
excellent results for trueness and selectivity. Furthermore, sensitivity
was achieved at a level of 0.1% (w/w) for assessed peptides. Summing
up, the developed method seems to be suitable for routine analysis
after verification by ring trials.