摘要
在聚乙烯醇(PVAVA)存在下,铱与钼酸盐和罗丹明B(RB)形成离了缔合物。缔台物的最大吸收位于570nm摩尔吸光系数ε8.36×10 ̄5’L·mol ̄-1·cm ̄-1,服从比尔定率范围为0~2.75μglr/25ml。测定2.0μg铱的相对标准偏差为2.5%(n=7),检出限43n/ml(n=12)。测定铱的适宜条件为CHClO_4=0.93mol/L,C_MoO ̄2-_49.0×10~-4mol/L,C_RB=3.3×l0 ̄-5mol/L,PVAO08%。试验了30多种共存离子的影响,除形成杂多酸元素和贵金属干扰外.大多数贱金属不干扰。用平衡移动法测定缔合物的摩尔比InRB=1:4,初步探讨了反应机理。所提出的方法已用于冶金产品及岩矿中铱的测定,结果满意。
A new spectrophotometric method for the determination of iridium has been developed, is based on the reaction of iridium with molybdate and rhodamine B(RB) to form an ion - associate complex in the presence of polyvinyl alcohol(PVA).The ion associate complex exhibits maximum absorptivity at 570 nm, with apparent molar absorptivity8.36 × 10~5L· mol^-1· cm^-1 Beer’s law is obeyed in the range of 0-2.75μg/25ml for lr(Ⅳ).The detection limit is 4.3ng/25ml(n=12)and relative standard deviation of 0.08μg/ml of Ir is 2.5%。(n=7).Over 30 foreign ions were tested for interferenceOther noble metal ions, sb (Ⅲ),Ge(Ⅳ)and si (Ⅳ)interfered and had to be separated from iridium by a fire assay.The optimum conditions for the determination of lr are 0,93mol/Lof HClO_4,9.0 × 10^-4mol/L of MO^2-_4,3.3 ×10^-5mol/Lof RB and 0.08% of PVA. The proposed method was used to determine Ir in some ores and metallurgical products.The molar ratio are established to be lr : RB=1: 4 by the equilibrium shift method.
出处
《冶金分析》
CAS
CSCD
北大核心
1995年第2期19-21,共3页
Metallurgical Analysis
基金
云南省自然科学研究基金