磷钨钼-罗丹明G-OP法测定痕量磷

Determination of Trace Phosphorus with Rhodamin G-Phosphomolybdenotungstate-OP System

研究了钨酸盐和还原剂对溶液中罗丹明 G(Rh G) -杂多阴离子缔合物稳定性的影响。结果表明 ,含钨杂多阴离子的形成、杂多阴离子被还原以及 OP的加入都能提高离子缔合物的稳定性。利用 Rh G-磷钨钼杂多酸 - OP的快速、稳定、灵敏的显色体系 ,建立了一种水相测磷的新方法。该离子缔合物在 5 88nm处有最大吸收 ,缔合物的表观摩尔吸光系数 ε=1.1× 10 5L· mol-1· cm-1。体系在 0— 6 .0 μg/ 5 0 m

The effects of WO 2- 4,reductants and surfactants on the stability of rhodamine G heteropolyanion associate in aqueous solution were investigated.The results show that the stability of the associate was increased by the formation of the heteropolyanion containing tungsten,the reduction of the heteropolyanion and addition of surfactants such as OP.A rapid,stable and sensitive colour reaction of rhodamine G(RhG) phosphomolybdenotungstate OP system was developed for the direct determin ation of phosphorus in aqueous solution.The ionassociate exhibits maximum absorptivity at 588nm and its apparent molar absorptivity is 1.1×10 5L·mol -1 ·cm -1 .Beer′s law is obeyed in the range of 0-6.0μg /50mL.