全蒸发-热电离质谱法的原理、技术和应用

Principle, Technology and Application of Total Evaporation Thermal Ionization Mass Spectrometry

  • 摘要: 全蒸发-热电离质谱法(total evaporation thermal ionization mass spectrometry, TE-TIMS)无需标准物质进行校正,即可获得高准确度同位素丰度比值测量结果,同时具有样品用量少、重复性高等优点,在核工业、环境、地质、计量学等领域逐渐获得了认可与应用。本文从全蒸发-热电离质谱法的原理、技术特点、研究进展和重要应用等方面对其进行了系统地评述,分析该方法在使用中的关键技术点,并对未来发展进行了展望。

     

    Abstract: Total evaporation thermal ionization mass spectrometry (TE-TIMS) has gradually gained recognition and application in the fields of nuclear industry, environment, geology and metrology due to its advantages including small sample dosage, good reproducibility, high accuracy and theoretically mass bias free nature. Due to the low thermal ionization efficiency and imperfect ion transmission, the establishment of TE-TIMS needs four prerequisites. Firstly, the ionization efficiency should be constant throughout the TE process. Secondly, the ion transmission efficiency should be constant throughout the TE process. Thirdly, the detection probability should be consistent for different isotopes. Fourthly, the ion loss before TE analysis should be negligible compared with the total signal. However, in practical, these prerequisites are difficultly satisfied completely, resulting in measurement uncertainty. In order to obtain more accurate TE-TIMS results, several improvements have been made during the last two decades, including introducing regular interruptions during TE process for ion-beam re-focusing, peak centering and peak tailing correction, combining with other mature methods, improving detector sensitivity, and establishing perfect uncertainty evaluation procedure, etc. In this review, the principle and the technical characteristics of TE-TIMS were introduced. Then, the methodology developments of TE-TIMS and its applications in nuclear industry, environment, geology and metrology were summarized. Finally, the development tendency of TE-TIMS was prospected.

     

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