Publications by authors named "M A Boillat"

Background: The separation performance of drift tube ion mobility spectrometers is usually relatively weak with resolving powers well below 100. Improving this aspect requires, besides the optimization of other parameters, the challenging increase of the drift voltage as deduced from fundamental equations describing the broadening of a drifting ion swarm. We recently succeeded in constructing an improved high voltage instrument equipped with an electrospray source capable of analysing liquid samples with resolving powers above 200.

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The pulsing circuitry for high resolving power drift-tube ion-mobility spectrometry is based on three avalanche photodiodes. These are switched on by illumination through optical fibers, which provide electrical insulation of the driver circuitry from the high voltage. The setup was tested with a series of quaternary ammonium ions introduced with an electrospray ion source.

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Temporal-bone milling is a delicate process commonly performed during otologic surgery to gain access to the middle and inner ear structures. Because of the numerous at-risk structures of this anatomic area, extensive surgeon training is required. Artificial temporal bones offer an interesting alternative to cadaveric training.

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A proof-of-concept study of the utilization of a single mass spectrometer for qualitative molecular analysis as well as for quantitative metal determination is described. This was performed with an argon microwave plasma as the ion source coupled to an ion trap mass spectrometer. A microwave induced plasma with tuneable power and gas flow rate was loaded with dried nebulized sample solutions.

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An easily built drift tube instrument with ring electrodes made of rolled-up flexible printed circuit boards is reported. Its resolving power was maximized by careful attention to the drift tube geometry and the response time of the detector amplifier and by employing a high separation field strength. The separation of singly charged aliphatic quaternary ammonium ions introduced by electrospray was performed, and the measured resolving power was between 86 and 97% of the theoretical limit for three different drift tube lengths investigated.

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