Fig. 1

The profile of protein adsorption capacity at various pH (trisodium citrate concentration 0.5 M) (a), various trisodium citrate concentration (protein adsorption at pH 4.0) (b), point of zero charge of Fe₃O₄ and Fe₃O₄-CA (trisodium citrate concentration 0.5 M) (c), and pI of leucaena protein (d)