Analytical Sciences

Abstract − Analytical Sciences, 27(5), 483 (2011).

High-throughput Total Cupric Ion Reducing Antioxidant Capacity of Biological Samples Determined Using Flow Injection Analysis and Microplate-based Methods
Joana P. N. RIBEIRO, Luís M. MAGALHÃES, Salette REIS, José L. F. C. LIMA, and Marcela A. SEGUNDO
REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 164, 4099-030 Porto, Portugal
High-throughput cupric ion reducing antioxidant capacity (CUPRAC) methods were developed for assessment of total antioxidant capacity (TAC) in urine and serum, based on reduction of Cu(II)-neocuproine complex to highly colored Cu(I)-neocuproine complex, measured spectrophotometrically at 450 nm. The reaction time was significantly reduced from 30 to 4 min by application of a calibration compound (uric acid) with kinetic behavior similar to that shown by urine samples. The method was implemented in a microformat (96 well plates) and also in an automatic fashion (flow injection analysis, FIA). A determination throughput value of 288 h−1 (microplate method) or of 15 h−1 (automatic FIA) was attained. Application of both methods to human serum (SRM 909b, level I) and urines (n = 9) provided TAC values in agreement with those of the end-point batch method.