Carrier-mediated hollow fiber liquid-phase microextraction for preconcentration followed by spectrophotometric determination of amoxicillin

Development of an orbital shaker-assisted fatty acid-based switchable solvent microextraction procedure for rapid and green extraction of amoxicillin from complex matrices: Central composite design

In this study, a cheap, fast and simple orbital shaker-assisted fatty acid-based switchable solvent microextraction (OS-FASS-ME) procedure was developed for the extraction of amoxicillin (AMOX) in dairy products, pharmaceutical samples and wastewater prior to its spectrophotometric analysis. Fatty acid-based switchable solvents were investigated for extracting AMOX. The key factors of the OS-FASS-ME procedure were optimized using a central composite design. The linearity of OS-FASS-ME procedure was in the range 5-600 ng mL-1 with a correlation coefficient of 0.991. In five replicate experiments for 20 ng mL-1 of AMOX solution, the recovery and relative standard deviation were 95.8% and 2.2%, respectively. Limits of detection and quantification were found 1.5 ng mL-1 and 5 ng mL-1, respectively. The accuracy, precision, robustness and selectivity of the OS-FASS-ME procedure were investigated in detail under optimum conditions. The OS-FASS-ME procedure was applied to milk, cheese, wastewater, syrups and tablets. A comparison of the results obtained from the reference method and the OS-FASS-ME method showed that the OS-FASS-ME procedure can be successfully applied to complex matrices.

Spectrophotometric determination of lamotrigine in plasma samples: Ultrasound-assisted emulsification-microextraction based on a hydrophobic deep eutectic solvent followed by back-extraction

In this study, sensitive detection of lamotrigine in human plasma samples was realized at a low cost approach through ultrasound-assisted emulsification-microextraction based on using a hydrophobic deep eutectic solvent followed by back-extraction (USAEME-DES-BE) method. After extraction, detection and quantification of lamotrigine were done by spectrophotometry in the UV region. The hydrophobicity of the deep eutectic solvent not only eliminates the need of the third solvent as an emulsifying agent but also helps to retrieve lamotrigine from the DES by back-extraction to another aqueous phase. The back extraction process allowed the drug to be measured in the UV region. Central composite design in combination with a desirability function approach was applied for the optimization of the USAEME-DES-BE procedure. Essential factors in the method efficiency were discussed, such as back-extraction solution, time of back-extraction, the ratio of DES components, pH, the volume of DES, salt concentration, and sonication time. The method exhibited a wide dynamic linear range from 0.5 to 10 µg mL^-1 and a limit of detection of 0.15 μg mL^-1. The established method was successfully applied to determine lamotrigine in human plasma samples with satisfactory relative recoveries.