Adsorbed resin phase spectrophotometric determination of nickel

β-Cyclodextrin polymer (β-CDP) adsorbed resin phase spectrophotometry with 1-(2-pyridylazo)-2-naphthol (PAN) has been developed for the determination of nickel at the μg level in human hair and Auricularia auricula (a kind of edible fungi). Iron, manganese, copper, zinc, chromium and cobalt which form colored species with PAN in the resin phase, can be completely masked with the masking solution composed of sodium hexametaphosphate(8.00×10−3 mol/l), or sodium thioglycollate (4.00×10−3 mol/l) and EDTA (4.00×10−4 mol/l).