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Miniaturization of a planar‐electrode linear ion trap mass spectrometer
Author(s) -
Li Ailin,
Hansen Brett J.,
Powell Andrew T.,
Hawkins Aaron R.,
Austin Daniel E.
Publication year - 2014
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.6906
Subject(s) - quadrupole ion trap , ion trap , miniaturization , chemistry , mass spectrometry , electrode , analytical chemistry (journal) , optoelectronics , ion , mass spectrum , secondary ion mass spectrometry , nanotechnology , materials science , organic chemistry , chromatography
RATIONALE We describe the miniaturization of a linear‐type ion trap mass spectrometer for possible applications in portable chemical analysis. This work demonstrates the potential and the advantages of using lithographically patterned electrode plates in realizing an ion trap with dimension y 0 less than 1 mm. The focus of this work was to demonstrate the viability and flexibility of the patterned electrode approach to trap miniaturization, and also to discover potential obstacles to its use. METHODS Planar, low‐capacitance ceramic substrates were patterned with metal electrodes using photolithography. Plates that were originally used in a linear trap with a half‐spacing (y 0 ) of 2.19 mm were positioned much closer together such that y 0 = 0.95 mm. A capacitive voltage divider provided different radiofrequency (RF) amplitudes to each of 10 electrode elements (5 on each side of the ejection slit), and the capacitor values were adjusted to provide the correct electric field at this closer spacing. The length of the trapping region, 45 mm, is unchanged from the previous device. RESULTS Electron ionization mass spectra of toluene and dichloromethane demonstrate instrument performance, with better than unit mass resolution for the molecular ion and fragment ion peaks of toluene. Compared with the larger plate spacing, the signal is reduced, corresponding to the reduced trapping capacity of the smaller device. However, the mass resolution of the larger device is retained. CONCLUSIONS Lithographically patterned substrates are a viable pathway to fabricating highly miniaturized ion traps for mass spectrometry. These results also demonstrate the possibility of significant reduction of the ion trap volume without physical modification of the electrodes. These experiments show promise for further miniaturization using assemblies of patterned ceramic plates. Copyright © 2014 John Wiley & Sons, Ltd.