惰气熔融-红外吸收法测定高纯铜中痕量氧  

Determination of trace oxygen in high-purity copper by inert gas fusion-infrared absorption method

作　　者：曹飞飞[1,2] 周涛[2] 张东翔[1] 

机构地区：[1]北京理工大学化工与环境学院,北京100081 [2]中国计量科学研究院,北京100013

出　　处：《冶金分析》2015年第5期32-36,共5页Metallurgical Analysis

基　　金：科技部支撑计划课题(No.2013BAK12B02);国家质检总局技改项目(No.2014NIM16)

摘　　要：为降低氧的空白,在不添加助熔剂的条件下建立了惰性气体熔融-红外吸收法准确测定高纯铜中痕量氧的分析方法。实验表明：称取0.8g左右的样品,在标准石墨坩埚中进行测定,控制吹扫时间为35s,排气时间为25s,排气周期为2次,排气功率为4 500W,分析功率为4 000 W,测得空白标准偏差为0.027μg/g,氧的定量限可降至0.27μg/g。准确称取10~30μg高纯氧化铁于锡囊中,用于仪器的校正,获得校正系数为1.034,解决了没有合适标准物质的难题。采用实验方法对高纯铜实际样品进行测定,测得铜中氧的质量分数为2.43μg/g,相对标准偏差（RSD）不大于7.7%。在测量不确定度评定中考虑了校正样品测量重复性、氧化铁试剂纯度、样品测量重复性和空白等影响因素,计算得到铜中氧质量分数的不确定度为0.33μg/g（k=2）。在高纯铜中加入高纯氧化铁进行加标回收试验,回收率在100%~105%之间。In order to reduce the blank of oxygen, an analysis method for the accurate determination of trace oxygen in high-purity copper by inert gas fusion-infrared absorption was established without the addition of flux. The results indicated that the optimal experimental conditions were as follows： 0.8 g of sampie was determined in standard graphite crucible; the purge time was 35 s; the evacuation time was 25 s; the evacuation cycle was twice; the evacuation power was 4 500 W; the analytical power was 4 000 W. The standard deviation of blank was 0. 027 μg/g, and the quantitative limit of oxygen was reduced to 0. 27 μg/g. 10-30μg of high-purity iron oxide was accurately weighed in tin capsule for the correction of instrument. The correction coefficient was 1. 034, solving the problem that there was no standard certified reference material. The actual high-purity copper samples were determined by the proposed method. The found oxygen mass fraction in copper was 2. 43 μg/g. The relative standard deviation （RSD） was less than 7.7%. During the evaluation of measurement uncertainty, some influencing factors were considered including the measurement repeatability of calibration sample, the purity of iron oxide reagent, the measurement repeatability of sample and the blank. The uncertainty of oxygen mass fraction in copper was 0.33 μg/g （k=2）. The high-purity iron oxide was added into high-purity copper oxide for the recovery test, with the recoveries between 100% and 105%.

关 键 词：惰性气体熔融法 红外吸收法 高纯铜 痕量氧 

分 类 号：TG115.3[金属学及工艺—物理冶金]