Absolute quantification of gelatin peptides using LC-MS/MS based on simulated gelatinous matrix screening and application

Accurate absolute quantification of peptides in complex matrices using LC-MS/MS is often hindered by significant matrix effects, especially in the quantitative determination of gelatin peptides in food. This study developed a strategy to reduce matrix interference in LC-MS/MS quantification of gelatin peptides by screening a simulated matrix based on physicochemical similarity. Deer antler gelatin was hydrolyzed with eight proteases and comprehensively characterized. Multivariate analyses (PCA and HCA) identified the Compound proteinase hydrolysate as most closely resembling the Trypsin-digested matrix with minimal interference, and was selected for method development. The validated method for five characteristic peptides showed excellent linearity (12.5–500 ng/mL, r 2  > 0.998), with LOQs of 0.12–5.20 ng/mL, precision RSDs of 4.45–12.44%, and accuracy of 79.5–116.9%. It was successfully applied to quantify peptides in Cervidae antler gelatin, thereby providing a practical approach to improving reliability in food quality control.