Improving the sensitivity of miniature linear ion trap mass spectrometer by a DC voltage applied on the eject electrodes

Abstract

A miniaturized linear ion trap mass spectrometer with continuous atmospheric pressure interface has been built in our lab. Significant extension in mass range and reduction in power consumption have been realized by the supplemental alternating current frequency scan mode. However, relatively poor sensitivity has been witnessed, which is directly dominated by the detection efficiency of the ion detector. Theoretical analysis has been implemented to find ways to improve the detection efficiency. The results show that enhanced sensitivity can be obtained by applying a direct current voltage on the pair of electrodes in eject direction. Experiments show that the sensitivity has been improved by more than one time due to the application of direct current voltage. With this design, this homemade miniature linear ion trap mass spectrometer can be used to analyze more rarefied samples, especially to on-site chemical analysis and space application.

Towards Higher Sensitivity of Mass Spectrometry: A Perspective From the Mass Analyzers

“…By applying a DC voltage on the ejection electrodes in a LIT MS, the ions are moved from the central axis of the four electrodes to near the eject slit and were more easily ejected (Li et al, 2018). Xu's group proposed a quadrupole enhanced (QE) dipolar resonance ejection method which was implemented in their home-built "brick" mass spectrometer (Jiang et al, 2017;Jiang, et al, 2018).…”

Applications of Vacuum Measurement Technology in China’s Space Programs

“…6.1. Development of a Miniature Magnetic Sector MS. Aiming at space exploration, we have developed a series of mass spectrometers, including TOF MS [68][69][70], ion trap MS [71][72][73], and magnetic sector MS (MMS) [74][75][76], among which a miniature MMS has been constructed and launched to 499 km Earth's orbit along with an experiment satellite in 2012 [76]. Compared with other mass spectrometers, MMS's advantages lie in simplicity, stability, high mass resolution and mass rejection ratio, and superior abundance sensitivity, making it a selection for atmospheric composition analysis and isotopic analysis [77].…”

A newly developed prototype magnetic sector mass spectrometer with high resolving power

“…Mass spectrometry is one of the key science and technologies, which can qualitatively detect and quantify various unknown substances by obtaining information of atom, molecular mass and structures [1][2][3][4]. At the present time, the mass spectrometer instruments have emerged for some mainstream mass spectrometers [5][6][7][8][9], such as ion trap, quadrupole, time-of-flight (TOF) and magnetic sector. In contrast, as a traditional mass spectrometry analytical instrument [10,11], the magnetic sector mass spectrometer has the merits of simple structure, good qualitative capability, superior resolution and high stability [12][13][14][15].…”