title: Three phases hollow fiber LPME combined with HPLC-UV for extraction, preconcentration and determination of valerenic acid in Valeriana officinalis.
abstract: In the present work, the applicability of hollow fiber-based liquid phase microextraction (HF-LPME) was evaluated for the extraction and preconcentration of valerenic acid prior to its determination by reversed-phase HPLC/UV. The target drug was extracted from 5.0 mL of aqueous solution with pH 3.5 into an organic extracting solvent (dihexyl ether) impregnated in the pores of a hollow fiber and finally back extracted into 10 μ L of aqueous solution with pH 9.5 located inside the lumen of the hollow fiber. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME, including pH of the donor and acceptor phases, type of organic phase, ionic strength, the volume ratio of donor to acceptor phase, stirring rate and extraction time were studied and optimized. Under the optimized conditions, enrichment factor up to 446 was achieved and the relative standard deviation (RSD) of the method was 4.36% (n = 9). The linear range was 7.5-850 μg L⁻¹ with correlation coefficient (r²=0.999), detection limits was 2.5 μg L⁻¹ and the LOQ was 7.5 μg L⁻¹. The proposed method was evaluated by extraction and determination of valerenic acid in some Iranian wild species of Valerianaceae.
authors.affiliation: Department of Chemistry, Shahid Bahonar University of Kerman, 76175-133 Kerman, Iran.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Mirzaei
authors.forename: Hossein
authors.initials: H
authors.lastname: Dinpanah
mesh_terms: D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004987:Ethers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007192:Indenes / Q000032:analysis* / Q000302:isolation & purification; D009994:Osmolar Concentration; D010936:Plant Extracts / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012717:Sesquiterpenes / Q000032:analysis* / Q000302:isolation & purification; D012965:Sodium Chloride / Q000737:chemistry; D013997:Time Factors; D014632:Valerian / Q000737:chemistry*
chemical_list: D004987:Ethers; D007192:Indenes; D010936:Plant Extracts; D012717:Sesquiterpenes; C037133:valerenic acid; D012965:Sodium Chloride