以N-十二烷基二甲基铵基乙酸为增敏剂催化光度法测定锰

Catalytic Spectrophotometric Method for the Deterrmination of Trace Manganese(Ⅱ) with Dodecyl Dimethylamino Acetic Acid as Sensitizer

基于存在增敏剂N-十二烷基二甲基铵基乙酸（DDMAA）和活化剂氨三乙酸，锰（Ⅱ）催化高碘酸钾氧化萘酚绿B的反应，拟定了测定痕量锰的新催化光度法。本法在两性表面活性剂DDMAA存在下，灵敏度提高10．3倍（Mn^(2+)量为0~6．0μg/L）和5．3倍（Mn^(2+)量为6．0~14μg/L），相对标准偏差为0．5％，检出限为5．6×10^(-8)g/L，可用于酒样和谷物制品中锰的测定。

A new catalytic spectrophotometric method for the determination of trace Mn(Ⅱ ) has been developed. The method is based on the oxidation of naphthol green B(NGB) by potassium periodate in the presence of nitrilotriacetic acid as an activator and dodecyl dimethylamino acetic acid(DDMAA) as sensitizer. The mechanism of related reaction has been discussed. Because of the addition of DDMAA,the sensitivity raised 10. 3 times and 5. 3 times for the different concentration of Mn solution. The linear ranges of determination are 0 ~ 6 .0μg/L, and 6. 0 ~ 14 .0 μg/L, the relative standard deviation is 0. 5% (n = 11 ). The method has been used for the determination of Mn(Ⅱ ) in wine and cereal samples.