吸光度线性扩展法测定镨钕钐  

Ultraviolet Spectrophotometric Determination of Praseodymium, Niobium and Samarium by Using Linear Expansion of Absorbance

作　　者：陈励权[1] 张炜[1] 陈志彬 

机构地区：[1]兰州大学

出　　处：《兰州大学学报（自然科学版）》1997年第4期66-72,共7页Journal of Lanzhou University(Natural Sciences)

摘　　要：用吸光度线性扩展法测定镨、钕、钐．基于待测元素特征吸收峰下的吸光度在纪录仪上线性放大，提高了测定的灵敏度、准确度，扩大了测定浓度范围．分别选用的最大吸收波长是：λＰｒ＝４４４．７ｎｍ，λＮｄ＝７９４．２ｎｍ，λＳｍ＝４０１．７ｎｍ；吸光度相应峰高和浓度呈线性关系的范围是：Ｐｒ３＋为（０．２０～８．６）×１０－６ｍｏｌ／Ｌ；Ｎｄ３＋为（０．２０～２．４）×１０－６ｍｏｌ／Ｌ；Ｓｍ为（０．２０～３．０）×１０－５ｍｏｌ／Ｌ．在选用１０ｃｍ比色皿时，测定灵敏度为：Ｐｒ３＋为１．１μｇ／ｍｌｍｍ，Ｎｄ３＋为０．２２μｇ／ｍｌｍｎ，Ｓｍ３＋为４．６μｇ／ｍｌｍｍ．待测元素与稀土杂质浓度比为５１时无干扰，１１时只有个别元素有一定干扰．The ultraviolet spectrophotometric determination of praseodymium, niobium and samarium has been investigated by using linear expansion of absorbance. The method can increase the sensitivity, accuracy and range of determination. λmax at which determination was performed are Pr:444.7 nm; Nd:794.2 nm and Sm:401.7 nm. The linear ranges between peak height and concentration of Pr3+, Nd3+ and Sm3+ are (0.2～8.6)×10-6 mol/L; (0.20～2.4)×10-6 mol/L and (0.20～3.10)×10-5 mol/L, respectively. The sensitivities to determination of Pr3+, Nd3+ and Sm3+ are 1.1 ug/mL·mm;0.22 μg/mL·mm and 4.6 μg/mL·mm, respectively. The determination of Pr, Nd and Sm is not interfered by other rare-earth metals when the concentration ratio of Pr, Nd and Sm to other rare-earth metals is 5:1; when the ratio is 1:1, the determination is interfered by only a few other rare-earth metals.

关 键 词：镨 钕 钐 测定 吸光度线性扩展 分光光度法 

分 类 号：O614.33[理学—无机化学]