微波消解-激光荧光法测定土壤样品中微量铀  

Determination of Trace Uranium in Soil Samples by Microwave Digestion-Laser Fluorescence Method

作　　者：孙秉怡 全葳[1,2] 卢瑛[1] 涂兴明[1] 

机构地区：[1]中国原子能科学研究院辐射安全研究所,北京102413 [2]环境保护部核与辐射安全中心,北京100082

出　　处：《核化学与放射化学》2017年第4期268-272,共5页Journal of Nuclear and Radiochemistry

摘　　要：建立了一种快速、准确的分析测量土壤样品中微量铀的方法:微波消解样品-激光荧光法。该法利用微波消解技术极大地缩短了样品前处理时间,将前处理速度提高了十几倍,回收率可达到95%以上,同时避免了多个样品同时处理过程中交叉污染的问题。当样品溶液的pH值在6.5~7.5时,荧光强度最高,UO2+2与荧光增强剂形成的络合物最稳定,测量灵敏度最高,在实际样品测量时,应及时调节样品溶液的酸度,以及加入硝酸体系铀标准溶液后溶液的酸度;荧光增强剂、样品溶液、标准溶液等应提前放入仪器间,待温度稳定后再上机测定。仪器放置在温度相对稳定的房间,测定最佳室温为20~25℃。本方法的检出限为0.009μg/g,对于1.4~6.5μg/g的样品,方法精密度优于10%(n=9)。A fas t and accurate analysis method for the measurement of t race uranium in soil samples was established： microwave d ig e s t io n - la se r flu orescen ce me th o d . In th is m e th o d , microwave digestion technique was used to shorten the time of sample pretreatment. The processing speed increases more than ten times. The recovery rate can reach over 95 % . Meanwhile, it avoids the problem of cross contamination in the process of multiple samples simultaneously. When the pH value of the sample solution is in the range of 6. 5 to 7. 5, the fluorescence intensity is the highest, and the UO;＋ and the fluorescence enhancement are the most stable. The measurement sensitivity is the highest. In the process of actual sample measurement, the acidity of sample solution should be adjusted in time, and the acidity of the solution of the standard solution of uranium in the nitric acid system. Fluorescence enhancement agent, sample solution, standard solution and so on are placed in the instrument, until the temperature is stable and then measure on the machine. The apparatusis placed in a relatively stable room, and the optimum temperature is 20-25 °C. The detection limit is 0. 009 yg/g, and the precision of the method is better than 10%（n=9） for 1. 4-6. 5 yg/g samples.

关 键 词：激光荧光法 微波消解 土壤样品 铀 

分 类 号：O655.2[理学—分析化学]