Abstract: An improved deposition aid for manual sample preparation, particularly on flat MALDI sample supports, comprises a holder for a sample support with several sample sites, which is adapted to standardized sample supports for ionization with matrix-assisted laser desorption and a device which projects a two-dimensional optical image, or a suitable sequence of images, onto the sample sites. The image, or sequence of images, is constructed such that a selected sample site or group of selected sample sites is highlighted in a way which can be perceived by the human eye, at least with respect to neighboring, not-selected sample sites. The deposition aid also includes an interface for confirming the manual deposition and/or a device for the automatic detection of a manual deposition process; and a guidance system which selects a sample site or group of sample sites, and controls the device accordingly.

Abstract: Mass spectrometry with lasers generates ions from analyte molecules by matrix assisted laser desorption for a variety of different mass spectrometric analysis procedures. The mass spectrometers with laser systems supply laser light pulses having at least two different pulse durations, and mass spectrometric measuring techniques use the laser light pulses of different durations. The duration of the laser light pulses allows the characteristics of the ionization of the analyte molecules, particularly the occurrence of the ISD (in-source decay) and PSD (post-source decay) types of fragmentation, whose fragment ion spectra supply different kinds of information, to be adapted to the analytic procedure.

Abstract: A method for operating an ion mobility spectrometer that comprises a measuring tube, a substance collector and a membrane inlet, the measuring tube, the substance collector and the membrane inlet defining a closed internal gas circuit, comprising separating the closed internal gas circuit from an external sample gas flow through the membrane inlet, transferring circulating gas containing an analyte substance from the membrane inlet to the substance collector, the analyte substance accumulated in the substance collector, releasing the accumulated analyte substances, and transferring the released analyte substances to the measuring tube.

Abstract: The invention relates to a method and a device for controlling the number of ions in ion cyclotron resonance (ICR) mass spectrometers, whereby the ions enter a multipole ion guide after their formation and are stored there temporarily. By measuring the ion number in a predefined subset of these temporarily stored ions, the number of ions transferred into the ICR trap for mass spectrometric analysis is regulated. A mode of operation of the multipole ion guide can ensure that undesirable mass ranges are filtered out before the transfer of ions into the ICR mass spectrometer. The invention makes it possible to eliminate space charge effects, which are caused by overfilling the ICR traps.