A Microelectromechanical Systems-Enabled, Miniature Triple Quadrupole Mass Spectrometer

Abstract

Miniaturized mass spectrometers are becoming increasingly capable, enabling the development of many novel field and laboratory applications. However, to date, triple quadrupole tandem mass spectrometers, the workhorses of quantitative analysis, have not been significantly reduced in size. Here, the basis of a field-deployable triple quadrupole is described. The key development is a highly miniaturized ion optical assembly in which a train of six microengineered components are employed to generate ions at atmospheric pressure, provide a vacuum interface, effect ion guiding, and perform pre-filtering, fragmentation and mass analysis. Despite its small dimensions, the collision cell efficiently fragments precursor ions and yields product ion spectra that are very similar to those recorded using conventional instruments. The instrument has been used to detect Thiabendazole, a common pesticide, in apple pulp at a level of 10 ppb.3

Miniature and Fieldable Mass Spectrometers: Recent Advances

“…102 Recently, Microsaic Systems reported the development of a fieldable triple quadrupole mass spectrometer. 103 The triple quadrupole geometry provides tandem mass spectrometry (MS/MS) capabilities not available in single quadrupoles. The microengineered system from Microsaic consisted of a microspray source, two quadrupole guides (one of which is a collision cell) 2.0 cm in length, and two quadrupole mass filters 5.3 cm in length, which are supported by ceramic boards.…”

“…The newly developed MEMS triple quadrupole instrument from Microsaic Systems has similar specifications but gains selectivity from integration of a collision cell for MS/MS. 103 The Expression line of mass spectrometers from Advion, the compact mass spectrometer (CMS), the L, and the S, are also targeted to LC detection. 216 These instruments easily fit within a fume hood, have a large mass range (up to m/z 2,000 for the L instrument), and obtain unit resolution over that range.…”

Development of a miniature mass spectrometer with continuous atmospheric pressure interface

“…31 Generally speaking, two types of miniature mass spectrometers have been developed on a system level up to now: 1) miniature mass spectrometers with continuous gas inlets and internal ionization sources, [32][33][34][35][36][37] which could only analyze 4 gas or volatile samples. 31 Generally speaking, two types of miniature mass spectrometers have been developed on a system level up to now: 1) miniature mass spectrometers with continuous gas inlets and internal ionization sources, [32][33][34][35][36][37] which could only analyze 4 gas or volatile samples.…”

Use of primary literature in the undergraduate analytical class

“…For example, after doing the assignment for mass spectrometry, students might be given data from ref. [27] and asked to determine the resolving power and mean free path of ions in the mass spectrometer. On the basis of these answers, students then explain whether they think the instrument described in the paper is a Q-TOF or a triple quad and suggest a suitable fragmentation method for tandem MS experiments on this instrument.…”