Effects of various factors of ultrasonic treatment on the extraction recovery of drugs from fish tissues.

In the present research, a combined extraction method of ultrasound-assisted extraction (UAE) in conjunction with solid phase extraction (SPE) was applied to isolation and enrichment of selected drugs (metoprolol, ticlopidine, propranolol, carbamazepine, naproxen, acenocumarol, diclofenac, ibuprofen) from fish tissues. The extracted analytes were separated and determined by ultra-high performance liquid chromatography with UV detection (UHPLC-UV) technique. The selectivity of the developed UHPLC-UV method was confirmed by comparison with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The important parameters, such as composition of type and pH of extraction solvent, solid/liquid rate volume of extraction solvent and number of extraction cycles were studied. The ultrasonic parameters, such as time, power and temperature of the process were optimized by using a half-fraction factorial central composite design (CCD). The mixture of 10 mL of methanol and 7 mL of water (pH 2.2) (three times) was chosen for the extraction of selected drug from fish tissues. The results showed that the highest recoveries of analytes were obtained with an extraction temperature of 40°C, ultrasonic power of 300 W, extraction time of 30 min. Under the optimal conditions, the linearity of method was 0.12-5.00 μg/g. The determination coefficients (R(2)) were from 0.979 to 0.998. The limits of detection (LODs) and limits of quantification (LOQs) for the extracted compounds were 0.04-0.17 μg/g and 0.12-0.50 μg/g, respectively. The recoveries were between 85.5% and 115.8%.