CLAUDIA-VALENTINA POPA, ANDREI FLORIN DANET, SILVIU JIPA, TRAIAN ZAHARESCU DETERMINATION OF TOTAL ANTIOXIDANT ACTIVITY OF WINES USING A FLOW INJECTION METHOD WITH CHEMILUMINESCENCE DETECTION
Total antioxidant capacity (TAC) of several samples of red and white wines was investigated by means of a new analysis method of flow injection with chemiluminescence detection ((FIA-CL). The applied method is based on a chemiluminescence reaction between luminol and hydroxyl radicals generated by the hydrogen peroxide in the presence of Co(II) ions complexed with ethylene diamine tetraacetic acid (EDTA) disodium salt according to a Fenton-type reaction. The FIA-CL assembly is made of three channels through which corresponding liquids are pumped: a carrier flux of 0.05M, pH 9 sodium borate solution where the analyzed sample is injected, a H2O2 flux and a flux containing CL reagent, that is a Co(II)/EDTA/luminol solution. This method allows for TAC determination within 2.5 – 300 mmoles L-1domains of gallic and caffeic acid, and with a relative standard deviation (RSD) = 2.41% (n = 10) when gallic acid concentration is 35 mM. The TAC values determined for the analyzed wine samples ranged between 0.19 and 0.55 g of gallic acid equivalents/L wine and between 0.44 and 1.78 g caffeic acid equivalents/L wine.