Optimization of ultrasound-assisted dispersive liquid–liquid microextraction of niacinamide in pharmaceutical and cosmetic samples using experimental design

Abstract

In this paper, an efficient and inexpensive analytical procedure using sugar alcohol-based deep eutectic solvent ultrasound-assisted dispersive liquid–liquid microextraction (DES-UA-DLLME) was optimized for the extraction of niacinamide from vitamin supplements, syrups and cosmetic samples. After the DES-UA-DLLME procedure, the niacinamide content in the samples was determined by UV–VIS spectrophotometer at 265 nm. Box-Behnken design was applied for the optimization of important variables that have a positive effect on extraction recovery of niacinamide. The optimum conditions included: DES-4 solution (mixture of sorbitol and glycerol with a molar ratio of 2:1) volume, 335 µL; pH, 6.1; sonication time 1.5 min; and extraction temperature, 30 °C. Using the optimum values, the DES-UA-DLLME procedure provides good linear range (1–400 ng mL−1), low detection limit (0.33 ng mL−1), high enrichment factor (2 2 7), quantitative recovery (97.3–98.9%) and good precision (1.4–2.8%). To investigate the validity of the optimized methodology, two standard reference material were analyzed with the DES-UA-DLLME-UV–VIS method. No significant difference was observed between the measured values and the reference values. The DES-UA-DLLME procedure can be successfully applied in routine analysis for extraction and determination of niacinamide in vitamin supplements, syrups and cosmetic samples.