Abstract
A simple flow injection analysis (FIA) integrating with a metal-free approach for total antioxidant capacity (TAC) was developed. The non-toxic reaction was based on generating a vibrant blue radical from imipramine to avoid the potential interferents arising from the colorful fruit extracts. The blue radical can be rapidly scavenged by antioxidant compounds present in the sample. TAC values of Thai tropical fruit extracts were assessed by monitoring the quenching in absorbance of the test mixture following the addition of the antioxidant compounds/fruit extracts. The FIA co-operated in order to increase the sample throughput. The results demonstrated that Antidesma thwaiteaianum Muell. Arg. has the highest capacity followed by Terminalia chebula Retz. and Phyllanthus Emblica Linn., respectively. An excellent correlation between the proposed method was found with the DPPH assay. The proposed method allowed the TAC determination of fruit extracts in a high-throughput and straightforward way in accordance with the principles of green analytical chemistry.