title: Application of micro-TLC to the total antioxidant potential (TAP) measurement.
abstract: DPPH is commonly applied for estimation of antioxidant capacity of single and complex biological samples, and changes colour from purple to yellow during reduction to DPPH-H. Importantly, for some samples, for example coloured foods, such reaction cannot be used because of interference from pigments. Therefore, the number of reported quantitative protocols involving off- or on-line sample reaction with DPPH are based on chromatographic separation of target components. In typical planar chromatographic assay, developed plates are sprayed with DPPH solution for antioxidant screening. Such approach enables simple visualisation of separated spots exhibiting antioxidant activities, but unfortunately, such procedure may also give the misleading signal for coloured spots. In the present communication we examined a new approach for measuring antioxidant capacity using quantitative analysis of DPPH and DPPH-H molecules after reaction with the sample, and then separated from the interfering compounds by micro-thin-layer chromatography. Particularly, the antioxidant capacities of coloured food samples (such as herbs and meads) were determined and the results compared with those obtained using the classical photometric assay. The main advantages of the new micro-TLC assay are (i) low cost, (ii) multiple measurements, (iii) short analysis time, (iv) simplification of sample preparation and (v) effective separation of DPPH signal from interfering compounds.
authors.affiliation: Department of Analytical Chemistry, Institute of Chemistry, Faculty of Science, Siedlce University of Natural Sciences and Humanities, 3 Maja 54, 08-110 Siedlce, Poland. Electronic address: bkg@onet.eu.
authors.forename: Bronisław K
authors.initials: BK
authors.lastname: Głód
authors.affiliation: Department of Analytical Chemistry, Institute of Chemistry, Faculty of Science, Siedlce University of Natural Sciences and Humanities, 3 Maja 54, 08-110 Siedlce, Poland.
authors.forename: Paweł M
authors.initials: PM
authors.lastname: Wantusiak
authors.affiliation: Department of Analytical Chemistry, Institute of Chemistry, Faculty of Science, Siedlce University of Natural Sciences and Humanities, 3 Maja 54, 08-110 Siedlce, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Piszcz
authors.affiliation: Department of Analytical Chemistry, Institute of Chemistry, Faculty of Science, Siedlce University of Natural Sciences and Humanities, 3 Maja 54, 08-110 Siedlce, Poland.
authors.forename: Elwira
authors.initials: E
authors.lastname: Lewczuk
authors.affiliation: Section of Toxicology and Bioanalytics, Faculty of Civil Engineering, Environmental and Geodetic Sciences, Koszalin University of Technology, Śniadeckich 2, 75-453 Koszalin, Poland.
authors.forename: Paweł K
authors.initials: PK
authors.lastname: Zarzycki
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002855:Chromatography, Thin Layer / Q000379:methods*; D005504:Food Analysis; D006722:Honey / Q000032:analysis; D010084:Oxidation-Reduction; D010783:Photometry / Q000379:methods; D010946:Plants, Medicinal / Q000737:chemistry
chemical_list: D000975:Antioxidants
keywords: DPPH(); Herbs; Mead; Micro-TLC; Total antioxidant potential