Determination of Manganese (II) in Foodstuffs by β-Cyclodextrin Polymer Phase Spectrophotometry with 1-(2-Pyridylazo)-2-naphthol

摘要

The chromogenic agent, 1-(2-pyridylazo)-2-naphthol (PAN) was included in β-Cyclodextrin polymer (β-CDP) and the modified polymer of inclusion of PAN (β-CDP-PAN) was obtained. Based on the fact that β-CDP-PAN can adsorb Mn (II) in solution to form Mn (II)-PAN complex, a sensitive and selective solid phase spectrophotometric method for the determination of trace amounts of Mn (II) has been developed. The maximum absorbance of Mn (II)-PAN complex in β-CDP was at 514 nm. The working range of the calibration graph was 2-12 μg of Mn (II). The interference of molybdenum, lead, cobalt, chromium, iron, nickel, zinc, tin, cadmium, and copper that form colored species with PAN in the polymer phase was investigated. The method was applied to the determination of Mn (II) in black rice and tea samples. A new method for the determination of trace amounts of manganese by polymer phase spectrophotometry is described. Manganese reacted with 1-(2-pyridylazo)-2-naphthol (PAN) that was included in a β-cyclodextrin polymer. The absorbance of the colored polymer, packed into a 5mm quartz cell, was determined directly at 514 nm. The proposed method was applied to the determination of manganese in black rice and tea samples.