La-Ce法岩石标准物质和Ce同位素标准溶液研制  

A certificating study on La-Ce rock reference material and Ce isotopic standa rd solution

作　　者：杨红梅[1,2] 段桂玲[2] 凌文黎[1] 

机构地区：[1]中国地质大学武汉地球科学学院,湖北武汉430074 [2]中国地质调查局宜昌地质调查中心,湖北宜昌443005

出　　处：《地球化学》2009年第2期179-186,共8页Geochimica

基　　金：地质调查测试新技术新方法研究计划项目(200120190099-03)

摘　　要：报道了La-Ce法岩石标准物质的研制结果。标准物质选自峨眉山玄武岩中的新鲜微晶玄武岩(编号EQB),具有间隐结构,矿物组成相对均一。岩石经粉碎和均一化加工,成为粉末后分装成1000小瓶。经均匀性和稳定性检验合格后,对该岩石标准物质的Ce同位素比值和La、Ce元素含量进行了测定和定值统计,其结果分别表示为:138Ce/142Ce=0.0225755±0.0000003,Ce=(117.4±1.3)μg/g,La=(55.8±0.9)μg/g。对二氧化铈化学试剂进行了溶液制备,以用于Ce同位素分析仪器标准物质。标准溶液编号为CBRICeO2,其138Ce/142Ce比值的测定统计值为0.0225748±0.0000006。为检验所制标准物质分析数据的准确度,对国际标样进行了比对测量,其中JMC304标准溶液的138Ce/142Ce比值测定结果为0.0225762±0.0000015,USGS玄武岩标样BCR-2的La和Ce元素含量测定结果分别为(25.2±0.6)μg/g(2σ)和(54.2±0.8)μg/g(2σ),所获数值与文献报道值或证书值在误差范围内相符。This presentation reports a certificating study on the natural basalt reference material for La-Ce isotopic analysis and Ce isotopic standard solution. The basalt （EQB） was collected from the Qingyin Power Station, Emeishan continental flood basalts in Sichuan Province and shows an alkaline basaltic feature. The surfaces of the rock pieces were cut away, and the clean remains were crashed and well mixed. The prepared powder was divided into 1000 aliquots, which were filled into 1000 bottles with a weight -10 g for each. Following the Chinese Reference Material Technical Regulation JJG1006-94, the homogeneity and stability tests of 138Ce/142Ce ratio and La, Ce contents were performed. The testing results demonstrate that the chemical homogeneity of basalt powder agrees with the regulation. The measurements of 138Ce/142Ce ratio and La, Ce contents of the EQB gave statistical referenced values of mCe/142Ce =0. 0225755 ＋-0. 0000003, Ce = （117.4± 1.3）μg/g and La = （55.8±0.9） μg/g. The Ce isotopic standard solution was prepared from a Cerium oxide powder （CBRI CeO2） with a purity of 99.999% , which gives a statistical referenced value of 0. 0225748 ±0. 0000006 for 138Ce/142Ce ratio. For comparing purpose, 138Ce/142Ce ratio for JMC304 solution and La, Ce contents for USGS BCR-2 standard were measured, which gave average values of 138Ce/142Ce = 0. 0225762 ± 0. 0000015 （2σ） for the standard solution, and La = 25.2μg/g and Ce = 54.2 μg/g for the basalt standard. These results are in good agreement with their reference values and/or their certificate values.

关 键 词：La-Ce法 标准物质 玄武岩 Ce标准溶液 定值推荐值 

分 类 号：P597[天文地球—地球化学]