Optimization of a high-resolution radical scavenging assay coupled on-line to reversed-phase liquid chromatography for antioxidant detection in complex natural extracts

This paper reports the optimization of the online coupling of 2,2’-azino-bis(3-ethylbenzothiazoline)-6 sulfonic acid based radical scavenging assays with reversed phase HPLC. The residence times in the reactor was reduced down to 6.4 seconds to ensure minimal peak broadening and loss of separation. Peak capacity losses between compound detection and measurement of the radical scavenging potential were reduced to 10% and lower on coupled column systems. The methodology was successfully applied for the detection of the scavenging activity of molecules encompassing a broad hydrophobicity range. The method shows promise for the assessment of low molecular weight polyphenols in red wine via coupled column high resolution HPLC-MS analysis