Simultaneous determination of 34 water-soluble flavor precursors in sheep meat using dispersed solid-phase extraction combined with liquid chromatography-tandem mass spectrometry.

Water-soluble flavor precursors (WSFPs) in sheep meat are key foundational substances that confer its unique and intense flavor. This study established an efficient analytical method for the simultaneous quantification of 34 WSFPs in sheep meat by combining streamlined sample preparation with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sheep meat samples were homogenized in water, followed by cleanup using dispersive solid-phase extraction (d-SPE), and subsequently analyzed by LC-MS/MS. Separation was achieved on a BEH Amide column (2.1 mm × 100 mm, 1.7 μm) with a gradient elution of ammonium formate aqueous solution and acetonitrile solution as the mobile phase. Detection was performed in electrospray ionization (ESI) mode with positive/negative ion switching and multiple reaction monitoring (MRM). Isotope-labeled internal standards were employed for quantification. The 34 analytes, spanning five chemical classes - 24 amino acids, 2 nucleotides, 3 reducing sugars, 4 small peptides, and 1 vitamin B1 (thiamine) - were successfully quantified. The method exhibited excellent linearity (R² ≥ 0.9909), with quantification limits ranging from 0.01 to 5 mg/kg, average spike recovery rates of 80.1%-109%, and relative standard deviations (RSD) below 9.9%. The developed method was validated using real sheep meat samples and demonstrated to be simple, accurate, reliable, and suitable for the simultaneous quantification of these 34 WSFPs. Furthermore, it proved applicable for monitoring changes in WSFP content during sheep meat storage.