Fig. 2.

Representative LC-MS/MS chromatograms (extracted ion chromatograms) of an incurred sample (tomato sauce) analysed using the S-Trap method with on-line SPE. Tomato sauce with (A) and without (B) seven raw ingredients added (wheat, buckwheat, egg, milk, crustacean [prawn], peanut, and walnut) and heated in an autoclave at 120 °C for 20 min. The concentration of protein in six of the ingredients (wheat, buckwheat, egg, milk, peanut, and walnut) in the sauce was 10 mg/kg. Crustacean (prawn) protein was added to the sauce at a concentration of 50 mg/kg.