title: Evaluation of the total antioxidant capacity by using a multipumping flow system with chemiluminescent detection.
abstract: An automated flow-based procedure for assessment of total antioxidant capacity was developed. It involved a multipumping flow system, a recent approach to flow analysis, and exploited the ability of selected compounds to inhibit the chemiluminescence reactions of luminol or lucigenin with hydrogen peroxide. The system included several discretely actuated solenoid micropumps as the only active components of the flow manifold. This enabled the reproducible insertion and efficient mixing of very low volumes of sample and reagents as well as the transportation of the sample zone toward a flow-through luminometer, where the chemiluminometric response was monitored. With luminol as the chemiluminogenic reagent, linearity of the analytical curves was noted up to 3.2x10(-4), 1.1x10(-3), and 8.8x10(-8) molL-1 for Trolox, ascorbic acid, and resveratrol, respectively. With lucigenin, linear calibration plots up to 2x10(-5) molL-1 of Trolox and 5.7x10(-5)molL-1 of ascorbic acid were obtained. As favorable analytical figures of merit, the measurement precision (RSD typically between 0.2 and 2.0%, n=10), low operational costs, low reagent consumption, sampling rate (160 and 70 h-1), and versatility should be highlighted. The proposed system can be used in distinct analytical circumstances without requiring physical reconfiguration.
authors.affiliation: Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, P.O. Box 96, Piracicaba 13400-970, Brazil.
authors.forename: Silvia R P
authors.initials: SR
authors.lastname: Meneses
authors.forename: Karine L
authors.initials: KL
authors.lastname: Marques
authors.forename: Cherrine K
authors.initials: CK
authors.lastname: Pires
authors.forename: João L M
authors.initials: JL
authors.lastname: Santos
authors.forename: Eduarda
authors.initials: E
authors.lastname: Fernandes
authors.forename: José L F C
authors.initials: JL
authors.lastname: Lima
authors.forename: Elias A G
authors.initials: EA
authors.lastname: Zagatto
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods; D008165:Luminol / Q000737:chemistry; D012680:Sensitivity and Specificity
chemical_list: D000975:Antioxidants; D008165:Luminol