Development of high performance liquid chromatography-ultraviolet detection method for screening mebendazole, clorsulon, diaveridine, and tolfenamic acid in animal-based food samples

This study focused on the detection and validation of the residues of the four veterinary drugs, mebendazole, clorsulon, diaveridine, and tolfenamic acid, using high performance liquid chromatography (HPLC) and an ultraviolet (UV) detector. Utilizing C18 column as a stationary phase and applying appropriate mobile phases to each analysis according to the properties of the analytes, target compounds in food samples were successfully detected and separated within 15-50 min. Additionally, in order to optimize detection, liquid-liquid extraction (LLE) and purification steps were established to minimize the endogenous peaks and their interferences. The method was validated through testing of linearity, accuracy, precision, the limit of detection (LOD) and the limit of quantification (LOQ). The LOQ levels of the four drugs were lower than the maximum residual limit, and the coefficient of determination (R²) was over 0.99. The recovery results ranged from 82.3-105.2%, 79.3-83.3%, 79.4-86.0%, and 81.7-88.5% with relative standard deviations lower than 20% for mebendazole, clorsulon, diaveridine, and tolfenamic acid, respectively, corresponding to the CODEX guideline. This proposed method reduces costs and enables easier application in rural or remote areas where testing facilities or instruments often are unavailable.