Antioxidant activity and corrosion inhibitive behavior of Garcinia cola seeds on mild steel in hydrochloric medium

In this work,the extract of garcinia cola seeds (egcs) has been studied as inhibitor mild steel in hydrochloric acid (1.0 m hcl) solution using by weight loss measurement,potentiodynamic polarization and electrochemical impedance spectroscopy (eis) techniques. the presence of this extract reduces remarkably the corrosion rate of mild steel in acidic solution. adsorption characteristic of the extract were approxilated by the langmuir isotherm. the results from this corrosion test clearly reveal that the extract behaves as a mixed type corrosion inhibitor with the highest inhibition at 100 ppm. double layer capacitance,(cdl) decrease indicates that a layer was form indicating the formation of a surface film. this reflects the inhibitor does retard the corrosion rate. further,antioxidant activity of the extract of garcinia cola seeds was determined by free radical 2,2-diphenyl-1-picrylhydrazyl (dpph) method.