Pulsed Acceleration Charge Detection Mass Spectrometry: Application to Weighing Electrosprayed Droplets

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• 作者：Sarah R. Mabbett ; Lloyd W. Zilch ; Joshua T. Maze ; John W. Smith ; Martin F. Jarrold
• 刊名：Analytical Chemistry
• 出版年：2007
• 出版时间：November 15, 2007
• 年：2007
• 卷：79
• 期：22
• 页码：8431 - 8439
• 全文大小：272K
• 年卷期：v.79,no.22(November 15, 2007)
• ISSN：1520-6882

文摘

We describe a new approach to measuring the masses ofindividual macroions. The method employs a pulsedacceleration tube located between two sensitive imagecharge detectors. The charge and velocity of the macroionare recorded with the first image charge detector. The ionis pulse accelerated through a known voltage drop, andthen the charge and velocity are remeasured using thesecond image charge detector. The mass of the ion isdeduced from its charge and its initial and final velocities.The approach has been used to measure masses in the10¹⁰-10¹⁴ Da range with z = 10³-10⁶ and m/z = 10⁶-10⁹. It should be extendable to masses of <10⁶ Da. Wehave used the method to determine the size and chargeof water droplets transmitted through a capillary interfaceand an aperture interface. The droplets detected from theaperture interface are ~1 order of magnitude smaller inmass than those detected from the capillary interface. Thedroplets from both interfaces have relatively low charges,particularly with the capillary interface where they are onlycharged to a small fraction of the Rayleigh limit. Theseresults suggest that the aerodynamic breakup of thedroplets plays a significant role in the mechanism ofelectrospray ionization.