Abstract: The invention relates to a method of a mass-spectrometric analysis of known mutation sites in the genome, such as single nucleotide polymorphisms (SNPs), using the method of restricted primer extension. The invention consists of the use of primers with a photocleavable linker. The linker creates a gap in a DNA strand which is almost the same size as a natural DNA building block (nucleoside). The linker forms a bridge over a base pair without inhibiting hybridization or enzymatic extension. However, the linker allows the primers to be cleaved after extension in order to obtain short DNA fragments which can be more easily detected on the mass spectrometer.

Abstract: An ion mobility spectrometer (IMS) has a non-radioactive electron source and an x-ray anode in an evacuated chamber. The impinging of electrons from the source on the anode results in the generation of x-ray radiation. The x-ray radiation passes through a window that provides a vacuum barrier between the electron source chamber and a reaction chamber of the IMS by an x-ray window. A support grid is attached to the reaction-chamber side of the x-ray window, and mechanically stabilizes the window.

Abstract: An ion mobility spectrometer (IMS) is provided that has a non-radioactive electron source in an evacuated chamber that is separated from the reaction chamber of the IMS by an x-ray window. Electrons from the source impinge upon an x-ray anode, causing the emission of x-ray radiation toward the window. A current controller is provided by which currents in the electron-source chamber are monitored and controlled using a microprocessor circuit. If a maximum permissible residual gas pressure is exceeded, the electron source is automatically shut down and a gettering process is activated.

Abstract: An ion mobility spectrometer (IMS) is provided that has a non-radioactive electron source in an evacuated chamber that is separated from the reaction chamber of the IMS by an x-ray window. Electrons from the source impinge upon an x-ray anode, causing the emission of x-ray radiation toward the window. A current controller is provided by which currents in the electron-source chamber are monitored and controlled using a microprocessor circuit. If a maximum permissible residual gas pressure is exceeded, the electron source is automatically shut down and a gettering process is activated.

Abstract: The invention relates to a method of a mass-spectrometric analysis of known mutation sites in the genome, such as single nucleotide polymorphisms (SNPs), using the method of restricted primer extension. The invention consists of the use of primers with a photocleavable linker. The linker creates a gap in a DNA strand which is almost the same size as a natural DNA building block (nucleoside). The linker forms a bridge over a base pair without inhibiting hybridization or enzymatic extension. However, the linker allows the primers to be cleaved after extension in order to obtain short DNA fragments which can be more easily detected on the mass spectrometer.

Abstract: An ion mobility spectrometer (IMS) has a non-radioactive electron source and an x-ray anode in an evacuated chamber. The impinging of electrons from the source on the anode results in the generation of x-ray radiation. The x-ray radiation passes through a window that provides a vacuum barrier between the electron source chamber and a reaction chamber of the IMS by an x-ray window. A support grid is attached to the reaction-chamber side of the x-ray window, and mechanically stabilizes the window.

Abstract: Ionization chamber, especially for an ion mobility spectrometer, with a non-radioactive electron source. The chamber consists of two compartments, of which one is evacuated and contains an electron source, and the other represents the reaction chamber of the IMS. In the evacuated compartment, X-ray quanta are produced in an anode by electron bombardment and these X-ray quanta can penetrate a partition between the two compartments. The partition between the two compartments is impermeable to electrons from the source and to gas molecules. In one or several conversion layers within the reaction compartment, X-ray quanta are converted to quanta of a lower energy and/or photoelectrons that can ionize the air constituents at a high level of efficiency.

Abstract: The invention relates to an analyzer for the identification of explosives and/or chemical warfare agents, with a neutron source which causes the emission of characteristic &ggr; quanta, whereby the analysis system consists of a mobile frame to which a neutron source and a detector as well as a holder for the object are attached, with a neutron generator which contains deuterium as the target, generates neutron pulses by periodically repeated, pulsed bombardment of the target and is controlled so that short neutron pulses are emitted and repeated periodically, whereby the detector is controlled so that in cycles it detects &ggr; quanta promptly emitted from the object due to inelastic neutron scattering and neutron capture, within at least two consecutive temporal measurement windows, whereby the first measurement window at least partially overlaps temporally the neutron pulse and the subsequent second measurement window does not, whereby in the first measurement window &ggr; quanta are essentially detected du

Abstract: The invention relates to a method and an ion mobility spectrometer (IMS) for the detection of contaminations by explosives, drugs, wood preservatives or the like. The substance traces collected on a carrier material, e.g. cellulose, are dissolved in a solvent for detection using an IMS and are vaporized together with this solvent from a sample dispenser in the reaction compartment of the IMS. In this way, the sample dispenser can be operated at a considerably lower temperature.

Abstract: The invention relates to a switchable ion mobility spectrometer (IMS) with ring electrodes divided into half-rings, which surround the drift chamber of the IMS. In a first operating condition, the two half-rings of each ring electrode are at the same potential and the various ring electrodes are at different potential varying monotonously along the drift path. In this way, ions are transported in the conventional manner along the drift path. In a second operating mode, the half-rings of the ring electrodes are at different potentials, by which the ions are each deflected toward one of the half-rings. The currents thus resulting are captured by the corresponding half-rings, amplified and an ion mobility spectrum is produced. A favorable design for the IMS can be used in many different modes of operation.

Abstract: An ion mobility spectrometer (IMS) with electric drift fields directed at a central detector electrode. The IMS is rotationally symmetrical and has a disk shape.

Abstract: The invention relates to a radioactive ion source for generation of low-energy .alpha. or .beta. radiation. Both the activity of the source as well as the range of radiation can be adjusted to the respective application. Due to a carrier layer of semiconductive material, release of radioactive substances is prevented.

Abstract: ECD with a non-radioactive electron source for generation of ions in a reaction chamber. The reaction chamber consists of two partial chambers, of which one is evacuated and contains the electron source, and the other contains connections for the feeding in of analysis gas as well as a collector electrode for detecting ions. The partition between the two partial chambers is permeable for electrons from the source but impermeable for gas molecules. The electron source may be a thermoemitter or a photocathode, which is irradiated from the outside through a window. In this way, contact between the analysis substance and the electron source is prevented, which increases measurement stability.

Abstract: In a method for photo-ionization ion mobility spectrometry, a reagent gas is added, in particular an aromatic compound, which has a large ionization cross section in the range of ionizing VUV radiation, but a low probability for the formation of protonated quasi-molecular ions. In this way, the detection of only weakly proton affine substances is also amplified or even made possible at all, and also the detection of electronegative substances in a negative operating mode is improved. Preferred reagent gases are benzene, toluene and xylene. FIG.

Abstract: Ion mobility spectrometer with a non-radioactive electron source to generate ions inside a reaction chamber. The reaction chamber consists of two partial chambers, one of which is evacuated and comprises the electron source, and the other one is connected to the drift chamber of the IMS via a shutter grid. The partition wall between both partial chambers is transparent to electrons but impermeable for gas molecules. The electron source may comprise a thermoemitter or a photocathode, which is illuminated from outside through a window. In this way, any contact between analyte and electron source is avoided, thereby improving the measuring stability and enabling operation in positive and negative mode.

Abstract: A method for measuring the mobility spectra of ions with ion mobility spectrometers (IMS). The method consists of impressing upon the essentially continuous ion flow of an IMS ion source, which comprises various ion types with various mobitities, a temporal switching signature with an ion admission of approximately 50% by using a very fast ion flow switch, whereby the signatures for the various ion types are displaced toward each other in different manners during the operating time due to the different velocities. From the quasi-continuously received ion current signal at the end of the path of the ion mobility spectrometer the composition of the ion types can be recovered according to mobility and intensity by decoding the switching signature. At the same time an improvement in resolution can be achieved by deconvolution of the diffusion profile. The method has a high duty cycle for the substance admitted and for the ions of ion flow.

Abstract: The invention concerns a gas tight drift chamber of an ion mobility spectrometer with ring electrodes separated by insulating rings. In order to simplify the construction and to improve the mechanical and electrical stability, the ring electrodes have a z-shaped cross section, into which the insulating rings with the rectangular cross sections are fitted. Electrodes and insulating rings are connected is in a gas-tight manner. The high voltage divider consists either of individual SMD resistors which are soldered or vapor deposited to the outside or of a highly resistively coated ceramic rod.