Development, Optimization, and Validation of a Sensitive UHPLC-MS/MS Method for the Determination of Hainanmycin in Chicken Meat and Eggs

This work presented an analytical method to determine hainanmycin in chicken meat and eggs using ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The extraction was carried out using a modified QuEChERS procedure followed by a cleanup combination of OASIS HLB SPE and freezing lipid filtration. The analyte was determined by UHPLC-MS/MS in positive ESI mode using ammonia adduct [M + NH₄]⁺ as the precursor ion. The method was comprehensively validated according to CIR (EU) 2021/808 and EURL Guidance Document on Confirmation Method Validation. The performance characteristics were linearity, decision limit (CCα), recovery, repeatability, within-laboratory reproducibility, matrix effect, selectivity, ruggedness, and stability. Good linearity was obtained in the 0.05–10 μg/L concentration range with coefficient of determination (R²) higher than 0.99. The CCα values ranged from 0.21 to 0.24 μg/kg; the average recoveries were 80.9–85.5%; and the repeatability and within-laboratory reproducibility were less than 10%. The validation results fulfilled the requirements of EU guidelines. Briefly, the proposed method achieved high sensitivity and accuracy, suitable for determining hainanmycin residue in chicken meat and eggs.