A corrosion inhibitor composition , which includes i ) an
aqueous alcohol base fluid , ii ) a mixture of at least three
polysaccharides selected from carboxymethyl cellulose ,
gum arabic , pectin , a salt of alginic acid , chitosan , dextran ,
hydroxyethyl cellulose , and soluble starch , with each poly
saccharide that is present in the mixture being present in an
amount of 0.05 to 0.5 wt . % , based on a total weight of the
corrosion inhibitor composition , iii ) silver nanoparticles ,
and iv ) a pineapple leaves extract . A method of inhibiting
corrosion of metal during acid cleaning / pickling whereby
the metal is treated with an acidic treatment fluid containing
an acid and the corrosion inhibitor composition
