Wei Cong, Garnick Kelly, Scott Thomas, Wetherby Anthony
Winchester Engineering and Analytical Center (WEAC), Office of Regulatory Affairs (ORA), The US Food and Drug Administration, 109 Holton Street, Winchester, MA 01890, USA.
J Radioanal Nucl Chem. 2019 Sep 4;322(2):263-269. doi: 10.1007/s10967-019-06724-1.
Based on the original work of Rutherford (Radio-activity, 1905) and Bateman (Proc Camb Philos Soc 15:423-427, 1910), the authors designed two schemes consisting of explicit equations as simple methods for accurately obtaining activity of Sr and Y before they reach secular equilibrium. Application of the methods to the Sr/Y system where Sr and Y are not in equilibrium will substantially reduce the time needed for determining activity of Sr because neither sequential measurements of Sr or Y (up to about 2 weeks) nor waiting for Sr and Y to reach equilibrium (more than 3 weeks) will be needed. We also implemented the explicit equations for decay/ingrowth correction of progeny's activity and applied them to the Zr/Nb system. Using the equations, the authors corrected activity concentrations of Nb to a designated reference time from the activity concentrations measured from samples at different times, for instance, 2, 8, 15, and 29 days after a reference time. During those measurement times, Nb and Zr were not in equilibrium. The corrected Nb activity concentrations were within an accuracy of - 10%.
基于卢瑟福（《放射性》，1905年）和贝特曼（《剑桥哲学学会会刊》15:423 - 427，1910年）的原始工作，作者设计了两个由显式方程组成的方案，作为在锶和钇达到长期平衡之前准确获取其活度的简单方法。将这些方法应用于锶和钇未达到平衡的锶/钇体系，将大幅减少测定锶活度所需的时间，因为既不需要对锶或钇进行连续测量（长达约2周），也不需要等待锶和钇达到平衡（超过3周）。我们还实现了用于子体活度衰变/增长校正的显式方程，并将其应用于锆/铌体系。使用这些方程，作者将不同时间（例如参考时间后2、8、15和29天）从样品测量得到的铌活度浓度校正到指定的参考时间。在这些测量时间内，铌和锆未达到平衡。校正后的铌活度浓度精度在 - 10%以内。
