Simultaneous determination of paracetamol and caffeine in aqueous samples by ultrasound-assisted emulsification microextraction coupled with high-performance liquid chromatography

Today, due to the growth of the pharmaceutical industry and the high consumption of drugs, monitoring of drug residues in environmental samples because of their destructive effects on the environment and humans is essential. In the present work, ultrasound-assisted emulsification-microextraction coupled with high-performance liquid chromatography as a simple and fast method was applied for simultaneous determination of paracetamol and caffeine in the aqueous samples. Effective parameters on the extraction efficiencies of these analytes such as type and volume of extraction solvent, pH of sample solution, salt concentration, sonication, and centrifuging times were studied and optimized. Under the optimum conditions, the calibration graphs were linear in the range of 30.0-1100.0 ng/mL for paracetamol and 50.0-400.0 ng/mL for caffeine. The limits of detection were 9.7 and 15.2 ng/mL for paracetamol and caffeine, respectively. The proposed method was successfully applied for the determination of these drugs in different aqueous samples.