Determination of absolute ion yields from a MALDI source through calibration of an image-charge detector
Determination of absolute ion yields from a MALDI source through calibration of an image-charge detector
复制标题
通过校准图像电荷检测器确定 MALDI 源的绝对离子产率
DOI：
10.1088/0957-0233/21/4/045802
复制
发表时间：
2010
影响因子：
2.4
通讯作者：
J. Greenwood
中科院分区：
文献类型：
--
作者：
J. Alexander;L. Graham;C. R. Calvert;O. Kelly;R. B. King;I. Williams;J. Greenwood
基质辅助激光解吸/电离（MALDI）是用于在气相中产生大分子生物离子的最重要的技术之一。令人惊讶的是，确切的电离机制仍然没有得到很好的理解，离子产率的绝对值是稀缺的。这部分是由于典型检测器的未知效率，特别是对于重生物分子离子。作为替代方案，可以使用图像电荷检测器非破坏性地检测带电粒子，其中输出电压信号与设备内的总电荷成比例。在本文中，我们报告了一个绝对校准，它提供了每个检测到的电子电荷在我们的实验安排的电压输出。需要至少3 × 103个离子才能在单次通过装置时区分出高于背景噪声的信号，这可以使用过滤技术进一步减少。校准结果已被应用到原始MALDI光谱，以测量绝对离子产率的基质和分析物离子。
MALDI (matrix-assisted laser desorption/ionization) is one of the most important techniques used to produce large biomolecular ions in the gas phase. Surprisingly, the exact ionization mechanism is still not well understood and absolute values for the ion yields are scarce. This is in part due to the unknown efficiencies of typical detectors, especially for heavy biomolecular ions. As an alternative, charged particles can be non-destructively detected using an image-charge detector where the output voltage signal is proportional to the total charge within the device. In this paper, we report an absolute calibration which provides the voltage output per detected electronic charge in our experimental arrangement. A minimum of 3 × 103 ions were required to distinguish the signal above background noise in a single pass through the device, which could be further reduced using filtering techniques. The calibration results have been applied to raw MALDI spectra to measure absolute ion yields of both matrix and analyte ions.