Determination of trace amounts of manganese by β-cyclodextrin polymer solid phase spectrophotometry using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol Original Research Article

A sensitive and selective solid phase spectrophotometric method for the determination of trace amounts of manganese has been described. The method is based on the inclusion of the chromogenic agent, 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in β-cyclodextrin polymer (β-CDP). The resin can adsorb manganese to form a colored complex with a maximum absorbance of 558 nm. The working range of the calibration graph was 0–8 μg of manganese. The interference from cadmium, lead, cobalt, molybdenum, chromium, iron, nickel, zinc, tin and copper that also form colored species with 5-Br-PADAP in the resin phase was investigated. The method is useful for the determination of manganese in black rice and tea.