摘要
在3.0mol·L-1H2SO4介质中,钯(Ⅱ)与试剂可形成稳定的配合物,而钴(Ⅱ)与试剂在pH 5.5的HOAc-NaOAc介质中才能定量配合,配合物形成后,用硫酸酸化至一定酸度时则转变为另一稳定的深色配合物。同时两者的吸光度于586nm波长处具有良好的加和性。据此,建立了钴、钯同时测定的方法,已用于合成样中微量钴、钯的同时测定。
The new reagent, 5-NO2-PADAT, reacts with Pd ( Ⅱ ) in a relatively high acidic medium of 3. 0mol · L-1 H2SO4 , to form a stable coordination complex with its absorption maxima at 591nm. The same reagent reacts with Co( Ⅱ ) in an acetate buffer medium of pH 5. 5 to form a stable coordination complex which keeps unchanged when the acidity of the solution is raised to 3. 0mol · L-1 H2SO4. The absorption maxima of the Co( Ⅱ) complex lies at 586nm. It is found that when the measurement is made at 586nm for both of the complexes of Pd( Ⅱ ) and Co( Ⅱ ), good additivity of the absorbances is obtained. Based on these facts, Co( Ⅱ ) and Pd( Ⅱ) can be determined simultaneously by taking two same aliquots of the sample solution, and carrying out the color reaction in one aliquot at 3. 0mol · L-1H2SO4 with its absorbance APd , and in another aliquot at pH 5. 5 and afterwards acidified to 3. 0mol · L-1 H2SO4 with its absorbance ACo+Pd. The absorbance of the Co( Ⅱ ) complex is obtained by the difference of ACo+Pd and APd. The proposed method has been applied satisfactorily to the analysis of simulated samples containing both Co( Ⅱ ) and Pd( Ⅱ ).
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2004年第10期581-583,共3页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
陕西省教育厅专项科研计划项目(00JK132)
