采用常规方法提取黄土-古土壤样品中的^10Be,制备BeO样品时,无法有效降低样品中B含量,导致在^10BeAMS测量中本底值偏高。本文对BeO制备方法进行了优化。新的制备流程改进了阳离子树脂交换、Be(OH)2转化为BeO的灼烧方式以及实验所采用的仪器设备。在西安加速器质谱仪(Xi’an。AMS)上测试结果表明,采用该化学流程制备的BeO样品化学本底可以达到2.04×10^-14。本文还介绍了Xi’an-AMS测量^10Be的方法与测量结果。
The classic procedure of BeO preparation for loess-paleosol cannot restrain the concentration of 10B effectively, which results in higher background of 10Be measurement. The procedure has been modified in this paper. It includes detailed eluting curve for cation exchanging, the method of converting Be(OH)2 to BeO, and the experiment equipments. The measurement results by Xi'an AMS indicate that the background of modified BeO preparation procedure can be lowered to 2.04×10^-14 on 3MV AMS. The method and measurement results have also been introduced for Xi' an-AMS.