高灵敏度卟啉试剂常温显色的研究及应用─不经分离用TPPS_4测定高纯铅中的铜  

RESEARCH ON AND APPLICATION OF CHROMOGENIC REACTION OF HIGH-SENSITIVITY PORPHYRIN REAGENT AT ROOM TEMPERATURE─DIRECT DETERMINATION OF COPPER IN HIGH PURITY LEAD WITH TPPS_4

作　　者：郭玉竹 孙龄高[1] 

机构地区：[1]北京矿冶研究总院

出　　处：《北京矿冶研究总院学报》1994年第1期90-94,共5页

摘　　要：提出了一种常温下用水溶性卟啉ＴＰＰＳ_４测定铜的高灵敏度分光光度法。在ｐＨ４．５～６．０的ＨＡｃ－ＮａＡｃ缓冲溶液中，在抗坏血酸存在下，铜与ＴＰＰＳ_４形成１：１的络合物，其稳定常数为Ｋ稳＝１．４×１０~８，λ_（ｍａｘ）＝４１２ｎｍ，ε_（４１２）＝３．９×１０~５ｃｍ^（－１）·ｍｏｌ^（－１）·Ｌ，铜在０～１．０μｇ／１０ｍＬ的范围内服从比尔定津。无需分离掩蔽，本法可直接用于高纯铅中痕量铜的分析；操作简便迅速，准确度满意。文中还就抗坏血酸促进反应的机理进行了初步的讨论。A method of high-sensitivity spectrophotometric determination of trace copper at room temperature by using water-soluble TPPS_4(P) as chromogenic reagent is presented.It was discovered that the complex of Cu and TPPS_4 was produced within 5min at room temperature in the range of PH 4.5～6.0,in the presence of ascorbic acid.The apparent molar absorbancy coefficient ε_(max) was 3.9 ×10￣5cm￣(-1)·mol￣(-1)·L at λ_(max)=412nm and the linear range Was 0～1.0μg Cu/10mL.By using the first derivative spectrophotometry,ε'might reach 6.7×10￣6,and the linear range could be 0～0.1μg Cu/10mL.The composition of the complex was 1:1.The stable constant(K),which was got by JOB method,Mol Ratio method and Equilibrium-shifting method,was 1.4×10￣8(lgK=8.15).The method can be directly used for determination of trace copper in high purity lead,with satisfactoryresults.Pb recovery was 90%～110% with high purity lead containing 0.00016% of Cu,the R.S.D.was 5.6%o(n=11).The method is simple and easy for use.In this paper,the mechanism of promotive reaction of ascorbic acid is also preliminarily discussed.

关 键 词：分光光度法 卟啉试剂 铜 高纯铅 

分 类 号：TG146.11[一般工业技术—材料科学与工程]