【摘要】 研究了钼 -铜 -硫脲 -硫氰酸盐 -罗丹明 B-聚乙烯醇高灵敏显色体系测定痕量钼的条件。缔合物最大吸收峰在 5 80 nm,表观摩尔吸收系数 ε=1 .6 6× 1 0 6L· mol- 1 · cm- 1 ,钼浓度在 0 .1 0 - 0 .5 0 μg/ 2 5 m L范围内符合比耳定律。并进一步讨论了显色反应的机理 ,认为显色体系中的物质是一种以 {[( Cux Moy Oz) p-·i A+· j SCN- ]k-·k RB+}的结构形式存在的大截面吸光粒子。更多还原

【Abstract】 A superhigh sensitive spectrophotometric method was developed for determination of trace molybdenum based on the formation of a complicated ionassociation complex with copper,rhodamine(RB) and thiocyanate in the presence of polyvinyl alcohol(PVA_~124).The ionassociation complex exhibits a maximum absorption at 580nm and ε=1.66×106 L·mol~-1·cm~-1;beer′s law is obeyed in the range of 0.10-0.50μg/25mL of Mo(Ⅵ).The method has been applied to determination of trace molybdenum in lettuce with satisfactory results.The reaction mechanism has also been discussed that the ionassociation complex is a big area particle composed of [(Cu_xMo_yO_z)~p-·iA·j SCN-]~k- and k RB+.更多还原