期刊
ANALYTICAL CHEMISTRY
卷 80, 期 21, 页码 7921-7929出版社
AMER CHEMICAL SOC
DOI: 10.1021/ac801712s
关键词
-
资金
- National Institute of Health [EB002016-15]
- National Science Foundation [CHE-0555314]
A hybrid quadrupole orthogonal time-of-flight mass spectrometer optimized for matrix-assisted laser desorption ionization (MALDI) and electrospray ionization has been equipped with a C-60 cluster ion source. This configuration is shown to exhibit a number of characteristics that improve the performance of traditional time-of-flight secondary ion mass spectrometry (TOF-SIMS) experiments for the analysis of complex organic materials and, potentially, for chemical imaging. Specifically, the primary ion beam is operated as a continuous rather than a pulsed beam, resulting in up to 4 orders of magnitude greater ion fluence on the target. The secondary ions are extracted at very low voltage into 8 mTorr of N-2 gas introduced for collisional focusing and cooling purposes. This extraction configuration is shown to yield secondary ions that rapidly lose memory of the mechanism of their birth, yielding tandem mass spectra that are identical for SIMS and MALDI. With implementation of ion trapping, the extraction efficiency is shown to be equivalent to that found in traditional TOF-SIMS machines. Examples are given, for a variety of substrates that illustrate mass resolution of 12 000 - 15 600 with a mass range for inorganic compounds to m/z 40 000. Preliminary chemical mapping experiments show that with added sensitivity, imaging in the MS/MS mode of operation is straightforward. In general, the combination of MALDI and SIMS is shown to add capabilities to each technique, providing a robust platform for TOF-SIMS experiments that already exists in a large number of laboratories.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据