title: Automated electrochemical free radical scavenger screening in dietary samples.
abstract: An automated electrochemical microtiter plate assay for the quantification of free radical scavengers (antioxidants) in food samples is described. Dietary antioxidant capacity measurements were achieved using the radical compound 2,2-diphenyl-1-picrylhydrazyl (DPPH·) as an amperometric redox indicator, with a pencil lead working electrode, in conjunction with a Pt counter-electrode and Ag/AgCl reference electrode, moving sequentially through the 24 vials of a standard 6 × 4 microtiter plate. Programmed analyses were performed successfully with synthetic antioxidants of known concentrations and with tea infusions, fruit juices, and vegetable extracts. The novel methodology is simple and convenient as, unlike common DPPH· antioxidant electroanalysis, it avoids the time-consuming cleaning of electrochemical cells between measurements. Microtiter plate-based robotic electrochemical antioxidant assaying is thus a good option for handling large sample collections and may be applicable in the production of food and herbal remedies.
authors.affiliation: Biochemistry-Electrochemistry Research Unit, School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
authors.forename: Sireerat
authors.initials: S
authors.lastname: Intarakamhang
authors.forename: Albert
authors.initials: A
authors.lastname: Schulte
mesh_terms: D001331:Automation; D001628:Beverages / Q000032:analysis; D001713:Biphenyl Compounds / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D016166:Free Radical Scavengers / Q000032:analysis*; D005638:Fruit / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D013662:Tea / Q000737:chemistry
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D013662:Tea; C004931:1,1-diphenyl-2-picrylhydrazyl