共振瑞利散射光谱法测定冶金样品中痕量铱(Ⅳ)
Resonance Rayleigh-Scattering Spectrometric Determination of Trace Amount of Iridium(Ⅳ) in Metallurgical Samples
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摘要: 稀硫酸介质中,在聚乙烯醇存在时,由铱(Ⅳ)与钨酸盐及罗丹明B形成的离子缔合物在612 nm附近产生强烈的共振瑞利光散射现象,据此提出了测定铱(Ⅳ)的共振瑞利散射光谱法.在优化后的试验条件下,共振散射光强度(ΔI)与铱(Ⅳ)的质量浓度在0.5~7.5 μg·L-1范围内呈线性关系,检出限(3σ)为0.25 μg·L-1,用于两种冶金样品中铱的测定,相对标准偏差(n=5)小于1.3%,加标回收率在98.0%~103.0%之间.Abstract: In a dil.H2SO4 medium,an ion-associated complex was formed among Ir(Ⅳ),tungstate and Rhodamine B in the presence of polyvinyl alcohol.The maximum value of intensity of resonance scattering of complex was obtained at the wavelength of 612 nm.A new resonance Rayleigh-scattering spectrometric method for the determination of Ir(Ⅳ) was proposed on these basis.Under the optimum conditions,linear relationship was kept between the values of intensity of resonance scattering (ΔI) and mass concentration of Ir (Ⅳ) in the range of 0.5-7.5 μg·L-1 with the detection limit (3σ) of 0.25 μg·L-1.In its application to the analysis of 2 metallurgical samples,values of RSD′s (n=5) obtained were less than 1.3%.Results of recovery test found by standard addition method were in the range of 98.0%-103.0%.