title: Determination of water-soluble vitamins in infant milk and dietary supplement using a liquid chromatography on-line coupled to a corona-charged aerosol detector.
abstract: A simple and rapid method for the simultaneous determination of seven water-soluble vitamins (thiamine, folic acid, nicotinic acid, ascorbic acid, pantothenic acid, pyridoxine and biotin) was developed by high performance liquid chromatographic separation and corona-charged aerosol detection. The water-soluble vitamins were separated on a Lichrosorb RP-C18 column under isocratic conditions with a mobile phase consisting of 0.05 M ammonium acetate:methanol 90:10 (v/v) at the flow rate 0.5 mL min(-1). The vitamins were extracted from the infant milk (liquid and powder format) using a precipitation step with 2.5 M acetic acid remaining the analyte in the supernatant. As far as dietary supplements are concerned, only a dilution with distilled water was required. The detection limits ranged from 0.17 to 0.62 mg L(-1) for dietary supplements and 1.7 to 6.5 mg L(-1) for milk samples. The precision of the method was evaluated in terms of relative standard deviation (%, RSD) under repeatability and reproducibility conditions, being the average values for each parameter 2.6 and 2.7 for dietary supplements and 4.3 and 4.6 for milk samples. The optimized method was applied to different infant milk samples and dietary supplements. The results of the analysis were in good agreement with the declared values.
authors.affiliation: Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building (Annex), Campus de Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Márquez-Sillero
authors.forename: Soledad
authors.initials: S
authors.lastname: Cárdenas
authors.forename: Miguel
authors.initials: M
authors.lastname: Valcárcel
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis; D001710:Biotin / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D019587:Dietary Supplements / Q000032:analysis*; D005492:Folic Acid / Q000032:analysis; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D057230:Limit of Detection; D016014:Linear Models; D009525:Niacin / Q000032:analysis; D010205:Pantothenic Acid / Q000032:analysis; D011736:Pyridoxine / Q000032:analysis; D015203:Reproducibility of Results; D013831:Thiamine / Q000032:analysis; D014815:Vitamins / Q000032:analysis*
chemical_list: D014815:Vitamins; D010205:Pantothenic Acid; D009525:Niacin; D001710:Biotin; D005492:Folic Acid; D011736:Pyridoxine; D001205:Ascorbic Acid; D013831:Thiamine
keywords: Charged aerosol detector; Dietary supplement; Infant milk; Liquid chromatography; Water-soluble vitamins