首次采用加速器质谱(AMS)方法对纳克(ng)级系列U同位素实验室标准:UBT-030、UBT-070、UBT-750以及流程空白(F_Blank)样品进行了系统化测量分析。实验采用绝对测量的方法,通过半导体(SBD)探测器直接测量同位素234U、235U、236U、238U的计数,然后通过扣除相应本底的方法得到系列同位素的比值。研究结果(图1和表1)表明,系列标准样品的测量值与理论值线 For the first time, a systematic measurement of the U-series U-isotope laboratory standards: UBT-030, UBT-070, UBT-750 and F_Blank samples was performed using accelerator mass spectrometry (AMS) Experiments using absolute measurement method, the semiconductor (SBD) detector directly measure the isotope 234U, 235U, 236U, 238U count, and then by subtracting the corresponding background method to obtain a series of isotope ratio. The results of the study (Figure 1 and Table 1) show the measured and theoretical values ​​of a series of standard samples