高碘酸钾氧化孔雀绿催化光度法测定超痕量锰

CATALYTIC SPECTROPHOTOMETRIC DETERMINATION OF ULTRATRACE AMOUNTS OF MANGANESE USING OXIDATION OF MALACHITE GREEN WITH POTASSIUM PERIODATE

本法基于存在氨三乙酸为活化剂、氟化钠为掩蔽剂,锰(Ⅱ)对高碘酸钾氧化孔雀绿的催化效应,并用正交设计法确定适宜的测定条件,本法测定锰的检测限为0.02ng/mL,可用于饮用水中锰的测定。

A high-sensitive and selective method for determining ultratrace amounts of Mn has recently been developed. The method is based on the catalytic oxidation of malachite green by potassium periodate in the presence of nitrilo triacetic acid as an activator and sodium fluoride as masking agent. Optimum experimental conditions has been established by means of orthogonal design. The detection limit for Mn is 0.02ng/mL. It is found that 10~7-fold Na^+,Cl^-,2×10~5-fold Pb^(2+), 10~5-fold NO_3^- and Br^-,2×10~4-fold SO^2_4^-,10~4-fold Cu^(2+), Hg^(2+),Mo(Ⅵ), 2×10~3-fold Ca^(2+),Mg^(2+),Zn^(2+),Co^(2+),Cr^(3+)and I^-,10~3-fold Ag^+, Al^(3+) and V (V), 2×10~2-fold Ni^(2+), and 100-fold Fe^(3+) do not interfere under the experimental conditions. The method is suitable for the direct determination of Mn in tap water and spring water.