Abstract: The metastable atom bombardment source provides a charged particle free beam of metastable species that can be used to bombard and ionize organic and inorganic substances in a gas phase. The metastable atoms are produced by inducing a discharge in a gas (rare gases or small molecules). The discharge is curved between the cathode and anode, with the cathode located in a medium pressure zone and the anode located off-axis in a low pressure zone. A nozzle located between the cathode and the anode provides a collimated beam of metastable atoms of low kinetic energy that is directed at an ion volume containing the substances to be analyzed. By selecting the energy of the metastable state, selective fragmentation of molecules, particularly large molecular weight molecules, can be carried out.

Abstract: For analyzing micro-organisms and other high-molecular weight species, a sample of the substance to be analyzed is prepared, placed in a pyrolyzer where it is pyrolyzed with a selected temperature program to provide pyrolyzed product of a high-dalton mass range. The product is ionized using metastable atoms which results in efficient ionization with little fragmentation. The metastable atoms are generated using a generator that provides a beam of metastable atoms which is basically free from ions. The ionized product is then analyzed using a high acquisition rate mass analyzer, such as a time-of-flight (TOF) analyzer.

Abstract: A method of processing data representing intensity values of a measurement signal as a function of a discrete variable such as time, which signal being characterized by series of peaks mixed with a substantially regular background noise, provides efficient noise attenuation and peak detection capabilities. When applied to a two-dimensional system, the method comprises an initial step of forming an intensity histogram vector representing a frequency distribution from the intensity values, which intensity histogram vector having N frequency vector components associated with corresponding N intensity sub-ranges within a maximum range extending from a minimum intensity value to a maximum intensity value. This initial step is followed by a step of zeroing a portion of the data corresponding to the intensity values which are below an intensity threshold value derived from shape characteristics of the distribution.

Abstract: The metastable atom bombardment source provides a charged particle free beam of metastable species that can be used to bombard and ionize organic and inorganic substances in a gas phase. The metastable atoms are produced by inducing a discharge in a gas (rare gases or small molecules). The discharge is curved between the cathode and anode, with the cathode located in a medium pressure zone and the anode located off-axis in a low pressure zone; A nozzle located between the cathode and the anode provides a collimated beam of metastable atoms of low kinetic energy that is directed at an ion volume containing the substances to be analyzed.