Coconut was obtained from the open market in Benin City,
Edo State of Nigeria. The fruits were dehusked, split, and sun
dried until the meat (endosperm) reaches 5% moisture content.
The copra was sliced and crushed in a food processing blender
and the oil extracted with hot water. The copra meal was then
washed several times with hot water to remove excess oil, sun
dried, and sieved to obtain particles of size less than 250 m. The
sieved copra meal was soaked in 0.02 mol/dm3 HCl overnight
to dissolve lignin and other plant materials. The acid solution
was filtered off, and the copra meal was washed with distilled
water until the pH of the wash became neutral. The copra meal
was dried at 373K for 24 h and stored in an air-tight container.
The stock solution of cadmium(II) (1000 mg/dm3) was prepared
in distilled water using cadmium nitrate salt (BDH); all working
solutions were prepared by diluting the stock solution with
distilled water.