A new catalytic spectrophotometric method for the determination of trace amount of Mn(Ⅱ) has been developed. The method is based on the oxidation of rhodamine B by potassium periodate in the presence of nitrilo triaceticacid as an activator and sodium dodecyl sulphate as sensitizer. The mechanism of related reaction has been discussed. As the addition of sodium dodecyl sulphate, the sensitivity raise 3.4 times. The linear range of determination is 10-120ng/25mL for Mn(Ⅱ). The detection limit is 8.0×10^-^1^1g/mL, the relative standard deviation is 2.6%(n=9). The method can be used for the determination of Mn(Ⅱ) in water and wine samples.

Key words: SURFACTANTS, MANGANESE, SYNERGISTS, RHODAMINE B, NITRILOTRIACETIC ACID, LAURYL SODIUM SULFATE, CATALYZING SPECTROPHOTOMETRY, POTASSIUM PERIODATE