title: Application of Optimized Vortex-Assisted Surfactant-Enhanced DLLME for Preconcentration of Thymol and Carvacrol, and Their Determination by HPLC-UV: Response Surface Methodology.
abstract: A novel vortex-assisted surfactant-enhanced dispersive liquid-liquid microextraction combined with high-performance liquid chromatography (VASEDLLME-HPLC) was developed for the determination of thymol and carvacrol (phenolic compound). In this method, the extraction solvent (CHCl3) was dispersed into the aqueous samples via a vortex agitator and addition of the surfactant (Triton X-100). The preliminary experiments were undertaken to select the best extraction solvent and surfactant. The influences of effective variables were investigated using a Plackett-Burman 2(7-4) screening design and then, the significant variables were optimized by using a central composite design combined with desirability function. Working under optimum conditions specified as: 140 µL CHCl3, 0.08% (w/v, Triton X-100), 3 min extraction time, 6 min centrifugation at 4,500 rpm, pH 7, 0.0% (w/v) NaCl permit achievement of high and reasonable linear range over 0.005-4.0 mg L(-1) with R(2) = 0.9998 (n = 10). The separation of thymol and carvacrol was achieved in <14 min using a C18 column and an isocratic binary mobile phase acetonitrile-water (55:45, v/v) with a flow rate of 1.0 mL min(-1). The VASEDLLME is applied for successful determination of carvacrol and thymol in different thyme and pharmaceutical samples with relative standard deviation <4.7% (n = 5).
authors: Chemistry Department, Yasouj University, Yasouj 75918-74831, Iran.
authors: Mehrorang
authors: M
authors: Ghaedi
authors: Young Researchers and Elite Club, Sepidan Branch, Islamic Azad University, Sepidan, Iran mostafaroosta.mr@gmail.com.
authors: Mostafa
authors: M
authors: Roosta
authors: Behbahan Khatam Alanbia University of Technology, Behbahan, Iran.
authors: Saeid
authors: S
authors: Khodadoust
authors: Department of Chemistry, University of Ilam, Ilam 65315-516, Iran.
authors: Ali
authors: A
authors: Daneshfar
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D000081007:Cymenes; D004867:Equipment Design; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D039821:Monoterpenes / Q000032:analysis*; D017830:Octoxynol / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D013943:Thymol / Q000032:analysis*
chemical_list: D000890:Anti-Infective Agents; D000081007:Cymenes; D039821:Monoterpenes; D013501:Surface-Active Agents; D013943:Thymol; D017830:Octoxynol; C073316:carvacrol