Abstract: The invention provides a method and system for analyzing a gas for the presence of a reactant compound via reaction of primary ions of a specific type. A source gas is introduced to a reaction chamber and ionized in this chamber. The pressure in the reaction chamber is adjusted to avoid the formation of protonated species and other impurities. The primary ions generated in the reaction chamber are transferred to a drift tube. The gas to be analyzed is diluted with a carrier gas and the resulting mixture is introduced into the drift tube. The ionization energy of the carrier gas is equal to or higher than the ionization energy of the primary ions. The product ions resulting in the drift tube from a reaction of the primary ions with the reactant present in the gas to be analyzed are then detected, for example using a mass spectrometer. Preferably, an existing PTR-MS setup is used to perform the method of the present invention.

Abstract: Instrument for analysing compounds, comprising an ion source, an adjacent drift tube and a mass spectrometer including an ion detector for separation and detection of product ions, wherein instrumental parameters of the instrument can be altered by actuating elements for actuating variables of at least one of the group consisting of ion source, adjacent drift tube, mass spectrometer and ion detector, characterized by a controlling unit which is connectable to a storage device, wherein the storage device comprises a specification for certain compounds, the specification for each compound comprising a set of data comprising at least two different instrumental parameters and corresponding intensity signals for product ions detected with the ion detector, wherein the controlling unit alters the actuating elements in accordance with the specification for each compound, wherein a correspondence signal is displayed on a display unit if the detected intensity signal for the product ion corresponds with the stored int

Abstract: The invention provides a method and system for analyzing a gas for the presence of a reactant compound via reaction of primary ions of a specific type. A source gas is introduced to a reaction chamber and ionized in this chamber. The pressure in the reaction chamber is adjusted to avoid the formation of protonated species and other impurities. The primary ions generated in the reaction chamber are transferred to a drift tube. The gas to be analyzed is diluted with a carrier gas and the resulting mixture is introduced into the drift tube. The ionization energy of the carrier gas is equal to or higher than the ionization energy of the primary ions. The product ions resulting in the drift tube from a reaction of the primary ions with the reactant present in the gas to be analyzed are then detected, for example using a mass spectrometer. Preferably, an existing PTR-MS setup is used to perform the method of the present invention.