Abstract: β-Cyclodextrin polymer (β-CDP) was synthesized using epichlorohydrin as the cross-linking agent. The chromogenic agent, 1-(2-pyridylazo)-2-naphthol (PAN) was included or adsorbed on β-CDP and the modified polymer of PAN inclusion in β-CDP (β-CDP-PAN) was obtained. A new resin phase spectrophotometry by PAN has been developed for determination of cobalt at the μg level in laver. Copper, chromium, iron, manganese, nickel, zinc and moylbdenum have had interference for the determination of cobalt, which formed colored species with PAN in the resin phase. The interference from iron, copper and nickel could be masked completely with the masking solution composed of EDTA (7.04×10-4 mol/L), and the rest could be eliminated by means of the strong acid. The proposed method was used to determine cobalt in laver and the result was satisfyactory. The experiments in addition, recovery and comparison showed that the method was accurate and reliable.

Key words: &beta, -Cyclodextrin polymer Resin phase spectrophotometry PAN Coba；