Micro-cloud point extraction for preconcentration of Aspirin in commercial tablets prior to spectrophotometric determination

A fast, simple, inexpensive and effective method is developed for spectrophotometric determination of Aspirin in commercial tablets based on micro-cloud point extraction ( MCPE ). The proposed MCPE is essentially a miniaturized form of traditional cloud point extraction ( CPE ) in which only a few microliters of micellar extracting phase is sufficient for spectrophotometric determination. For comparison with MCPE, cloud point extraction was examined for Aspirin extraction. Triton X-114 was employed as a non-ionic surfactant for extraction/preconcentration of aspirin. Factors influencing the extraction efficiency, such as concentration of Triton, effect of pH, type of dilution solvent, etc. were investigated and optimized. Under the optimized condition, linear calibration curve for MCPE was in the range of 0.05–2 mg/L and limit of detection of 0.05 mg/L was obtained, whereas linear part for CPE calibration curve was 0.9 to 11 mg/L with a limit of detection of 0.5 mg/L.