痕量银的催化动力学测定法研究

研究了在稀硫酸溶液中,在Ag⁺的存在下,K₄Fe(CN)₆和o-Phen的反应(银的新指示反应),反应机理为并用此来测定痕量银。根据Arrhenius方程式计算了催化和非催化反应的活化能,分别为64.15KJ/mol和96.89KJ/mol。本方法灵敏度为8×10^-12g·ml^-1,且选择性好。测定地质样品结果满意。平均标准偏差为0.024,变动系数2.43%。

The Study of the Determination of Trace Silver by Catalytic Kinetics

Anew indicator reaction catalyzed by silver has been studied. When silver is present K₄Fe(CN)₈reacts with o-phenanthroline in the solution of dilute H₂SO₄, the mechanism may be represented as follow:Fe(CN)₆^4-+3(o-Phen)^AgFe(o-Phen)₂(ornge)+6CN^-and trace silver could be estimated with the reaction.The apparent activation energies of catalytic and uncatalytic reaction are 64.15 and 96.89 kJ·mol^-1, respectively, was calculated by Arrhenius Formula.Compared with other methods, this one is higher sensilivity and selectivity. The sensitivity is 8×10^-12g·ml^-1.The method has been used for the determination of silver in geological samples with satisfactory results .The average standard deviation of determination is 0.024 and the average coefficient variation 2.43%.