title: Automatic determination of phylloquinone in vegetables and fruits using on-line photochemical reduction and fluorescence detection via solid phase extraction and flow injection.
abstract: A very simple, rapid and highly sensitive flow injection fluorimetric method was developed for the determination of phylloquinone. The assay was based on the on-line reduction of phylloquinone in dodecylsulfate micelles after irradiation with UV light. The micellar medium enhanced the fluorescence and stability of the reduced phylloquinone. Under optimum experimental conditions, the range of application of the technique was between 0.09 and 45.0 microg mL(-1) and the detection limit was 0.05 microg mL(-1). The sample throughput was 90 injections per hour. The reliability of the method for the routine analysis of phylloquinone in vegetables and fruits is demonstrated. Extractions were made with hexane, and an automated solid phase extraction system was used to purify the sample extracts prior to injection into the flow injection manifold.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071, Murcia, Spain. tpr@um.es
authors.forename: Tomás
authors.initials: T
authors.lastname: Pérez-Ruiz
authors.forename: Carmen
authors.initials: C
authors.lastname: Martínez-Lozano
authors.forename: Jesús
authors.initials: J
authors.lastname: Martín
authors.forename: Maria Dolores
authors.initials: MD
authors.lastname: García
mesh_terms: D002138:Calibration; D017022:Flow Injection Analysis / Q000379:methods*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000032:analysis; D005504:Food Analysis / Q000295:instrumentation* / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D008823:Micelles; D009862:Online Systems; D010084:Oxidation-Reduction; D010777:Photochemistry; D012967:Sodium Dodecyl Sulfate; D052616:Solid Phase Extraction / Q000379:methods*; D012996:Solutions; D014675:Vegetables / Q000737:chemistry*; D010837:Vitamin K 1 / Q000032:analysis* / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D008823:Micelles; D012996:Solutions; D012967:Sodium Dodecyl Sulfate; D010837:Vitamin K 1