Simultaneous Determination of Free Amino Acids, L-Carnosine, Purine, Pyrimidine, and Nucleosides in Meat by Liquid Chromatography/Single Quadrupole Mass Spectrometry

A novel approach to single-run determination of 25 free amino acids, L-carnosine, 4 nitrogen bases (purine and pyrimidine), and 5 nucleosides in unpurified biological samples is reported. The analytes were extracted from the sample, derivatized with dansyl chloride, and analyzed using RP-HPLC-DAD-ESI-MS. The reported method features high sensitivity (LOQs in 5–10 ng mL−1 range), wide linearity range with r > 0.94, and high precision (intra-day RSD within the 0.1–4.2% range). Analyte average recovery coefficient was in the 70.1–111.3% range. The method was used to determine levels of free amino acids, L-carnosine, nitrogen bases, and nucleosides in beef (strip loin). Evolution of concentrations of the studied compounds during meat storage processes (vacuum packing, cold storage) was also investigated.