Multiple Response Optimization of an Ionic Liquid-DLLME and UHPLC-DAD Analysis of Five Coccidiostats in the Chicken Liver with LC–MS/MS Confirmation

Pharmaceutical residues in animal food products from various sources are a crucial concern regarding food safety measures for human welfare. Coccidiostats are predominantly used in the poultry industry to prevent protozoal infection. Excessive use and slaughter before completion of withdrawal periods of drugs are likely to present residues in poultry products. As a result, humans may be exposed to these drugs through the consumption of poultry products. Therefore, we developed an ionic liquid-dispersive liquid‒liquid microextraction (IL-DLLME)-based method to evaluate the drug residues of five coccidiostats in chicken liver using UHPLC-PDA. The IL-DLLME extraction procedure was optimized using an experimental approach that included screening design, response surface methodology (RSM), and desirability function. After optimizing the necessary conditions, good linearity was achieved between 39 and 1250 ngmL⁻¹ with a coefficient of determination (R²) ≥ 0.999. The upgraded method showed excellent precision with a relative standard deviation (%RSD) ≥ 0.30–6.53% and significant recovery in the range of 61.57–107.49%. The limits of detection (LODs) and limits of quantitation (LOQs) for the five coccidiostats (UHPLC-PDA) ranged from 3.1 to 8.7 ngmL⁻¹ and 10 to 29 ngmL⁻¹, respectively. The developed method was applied to examine coccidiostats in chicken liver samples purchased from a local market. In addition, LC‒MS/MS analysis confirmed the presence of traces in liver samples. Thus, the developed method of extraction is precise and reproducible.