A Planar Integrated Micro-mass Spectrometer - LC-MS in Drug Bioanalysis - page 423

A Planar Integrated Micro-mass Spectrometer
Jörg Müller , Grigoriy Quiring , Maria Reinhardt-Szyba ,
Régulo Miguel Ramírez Wong , and Henning Wehrs
Abstract A planar fully integrated micro-mass spectrometer fabricated in a full
wafer based state-of-the-art MEMS technology in a glass-silicon-glass sandwich
is presented. Within a volume of 7 × 10 × 1.3 mm³ it contains all components of a
mass spectrometer, i.e., a microwave plasma electron source for ionization, an ion-
ization chamber, the electron and ion extraction, acceleration and focusing elec-
trodes, a new type of mass separator, a Faraday detector as well as structures for the
pressure management within the system for analyte, plasma gas, optics, and mass
separation. Also a spring arrangement to insert a self-aligning and contacting
microchannel plate (MCP) is included. The complete system is transferred from
one single photolithographic mask layer into a 2 ½ dimensional structure in a sili-
con substrate by ICP-etching. The designs of the subsystems, especially that of a
new type of separation principle, are presented and the layout of the injection sys-
tem and the batch processing of the device are outlined. A completely newly devel-
oped hardware and software of the electronics to drive the system is presented
including its physical layout and operational scheme. Actual spectra obtained with
the system demonstrate a mass resolution of 43 in a mass range of 0.5-200 and a
sensitivity of <100 ppm. Means to adapt the size of the periphery like vacuum
pumps, inlet pressure stages, and handling of liquid analytes, which would allow
for a really handheld device, conclude the contribution.
J. Müller ( * ) ￿ G. Quiring ￿ M. Reinhardt-Szyba ￿ R. M. Ramírez Wong ￿ H. Wehrs
Institute for Microsystem Technology, Hamburg University of Technology,
Hamburg , Germany
e-mail: [e-mail]; [e-mail]; [e-mail];
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