Vazquez Timothy, Taylor Colette, Knowlton Maverick, Williams Sean, Evans-Nguyen Theresa
J Am Soc Mass Spectrom. 2020 Jul 14. doi: 10.1021/jasms.0c00143.
For portable, remotely operated systems in space and defense, relaxed vacuum requirements are a strong advantage of ion trap mass analyzers. However, ion traps are believed to have insufficient capability for isotope ratio measurement because they fundamentally restrict sampling capacity. Focusing on modifications to the detection sequence of a digitally driven 3D quadrupole ion trap, operating in resonance ejection mode, we investigated improved performance for isotope ratio precision and accuracy. Due to xenon's inert nature and wide span of isotopes, xenon isotope ratios provide an excellent marker of processes (e.g. radioactive decay and planetary atmospheric escape) which would be ideally measured by in situ mass spectrometry. To target xenon isotope ratio analysis specifically, we implemented data acquisition system modifications for enhanced y-axis resolution measurements and signal filtering. In this manner, we show measurement precision improvements from ~±100 0/00 to ~±0.1 0/00 and accuracy improvements from ~30 0/00 to ~0.5 0/00 for our targeted isotopes of interest.
对于空间和国防领域的便携式远程操作系统而言，离子阱质量分析仪对真空要求较低，这是其一大显著优势。然而，人们认为离子阱在同位素比值测量方面能力不足，因为它们从根本上限制了采样能力。我们聚焦于对以共振喷射模式运行的数字驱动三维四极离子阱检测序列的改进，研究了其在同位素比值精度和准确性方面的性能提升。由于氙的惰性和广泛的同位素范围，氙同位素比值为某些过程（如放射性衰变和行星大气逃逸）提供了一个极佳的标记，而这些过程理想情况下可通过原位质谱法进行测量。为专门针对氙同位素比值分析，我们对数据采集系统进行了改进，以增强y轴分辨率测量和信号滤波。通过这种方式，我们展示了针对目标感兴趣同位素的测量精度从约±100‰提高到约±0.1‰，准确性从约30‰提高到约0.5‰。
