Hybrid QuEChERS–micro-scale solid-phase extraction for LC-MS/MS determination of chloramphenicol in milk and muscle

Introduction The determination of chloramphenicol (CAP) in milk and food-animal muscle is analytically challenging because of matrix complexity and matrix effects in LC-MS/MS analysis. Material and Methods A hybrid sample-preparation method combining QuEChERS extraction with micro-scale solid-phase extraction (MSPE) using C18P-PVDF microspin filters was developed for the determination of CAP in these matrices. The method was validated in accordance with European Commission Implementing Regulation (EU) 2021/808. Matrix effects and the influence of membrane type (PVDF, nylon or PTFE) were evaluated. Results The method demonstrated satisfactory analytical performance, with apparent recoveries ranging from 97.5% to 101.8%, repeatability below 10% and detection capability (CCβ) established at 0.12 µg kg −1 for both matrices. Matrix-effect values ranged from 91.8% to 111.2% for milk and from 89.1% to 112.3% for muscle. The best clean-up performance was given by PVDF membranes, which contributed to a stable analytical response during MSPE clean-up. Conclusion The proposed hybrid method provides effective clean-up and satisfactory control of analytical interferences without extensive additional clean-up procedures, making it suitable for routine determination of CAP in milk and muscle matrices.