title: Selective extraction and determination of vitamin B12 in urine by ionic liquid-based aqueous two-phase system prior to high-performance liquid chromatography.
abstract: A rapid and simple extraction technique based on aqueous two-phase system (ATPS) was developed for separation and enrichment of vitamin B(12) in urine samples. The proposed ATPS-based method involves the application of the hydrophilic ionic liquid (IL) 1-hexyl-3-methylimidazolium chloride and K(2)HPO(4). After the extraction procedure, the vitamin B(12)-enriched IL upper phase was directly injected into the high performance liquid chromatography (HPLC) system for analysis. All variables influencing the IL-based ATPS approach (e.g., the composition of ATPS, pH and temperature values) were evaluated. The average extraction efficiency was 97% under optimum conditions. Only 5.0 mL of sample and a single hydrolysis/deproteinization/extraction step were required, followed by direct injection of the IL-rich upper phase into HPLC system for vitamin B(12) determination. A detection limit of 0.09 μg mL(-1), a relative standard deviation (RSD) of 4.50% (n=10) and a linear range of 0.40-8.00 μg mL(-1) were obtained. The proposed green analytical procedure was satisfactorily applied to the analysis of samples with highly complex matrices, such as urine. Finally, the IL-ATPS technique could be considered as an efficient tool for the water-soluble vitamin B(12) extraction.
authors: Laboratory of Analytical Chemistry for Research and Development (QUIANID), Instituto de Ciencias Básicas, Universidad Nacional de Cuyo, Padre J. Contreras 1300, Parque Gral. San Martín, M5502JMA Mendoza, Argentina.
authors: Paula
authors: P
authors: Berton
authors: Romina P
authors: RP
authors: Monasterio
authors: Rodolfo G
authors: RG
authors: Wuilloud
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000191:economics / Q000379:methods*; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D052578:Ionic Liquids / Q000737:chemistry*; D013997:Time Factors; D016482:Urinalysis / Q000191:economics / Q000379:methods*; D014805:Vitamin B 12 / Q000302:isolation & purification* / Q000652:urine*; D014867:Water / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D014867:Water; D014805:Vitamin B 12