ABTS assay

The antioxidant potential of Oxalis corniculata Linn. in different solvent extracts and formulated soap were determined by ABTS free radical scavenging assay. Briefly, two solutions of 7 mM 2,2′-azinobis-(3-ethylbenzothiaziline-6-sulfonate) and 2.45 mM of potassium persulfate were mixed in 1 : 1 ratio and kept in the dark up to 24–48 h. Two millilitres of ABTS•+ solution diluted with aqueous methanol in 1 : 25 ratio was added in an aliquot of ten times diluted 20 µl plant extract and incubated at 30 °C followed by reading the absorbance at 734 nm after 0, 10, and 20 min where ascorbic acid serves as standard [32,34].