Abstract: The present invention is to provide a monitoring device making it possible to measure the concentration of a target trace gas which has an ionization efficiency changed by the affect of impurities and which is absorbed on a pretreatment portion or piping, at a high accuracy and at real time, by adding an internal standard having a known concentration to the target trace gas. The concentration of the target trace gas is measured while an internal standard having substantially the same properties (such as ionization efficiency change and vapor pressure) as the target trace gas is added. The ion strengths of the target trace gas and the internal standard are compared to calibrate the concentration of the target trace gas. According to the present invention, the concentration of the target trace gas in gas containing impurities can be online measured at a real time and at high accuracy while being continuously calibrated.

Abstract: A sample introduction probe for introducing a gas sample to a mass spectrometer, having an inner pipe for conducting the sample to be analyzed, and an outer pipe installed outside of the inner pipe. An opening is installed at one end of the inner pipe for enabling entry of the sample into the inner pipe. A pump is installed on a side of the one end of the inner pipe, and a probe tip heater is provided for heating the one end of the inner pipe, a heater for heating the inner pipe.

Abstract: To provide a mass spectrometer having a high sensitivity to dioxins. In the mass spectrometer including: a sample supply tube for supplying a sample solution containing a sample to be measured; a nebulizer for nebulizing the sample solution supplied from the sample supply tube; an ion source having a needle electrode for ionizing the sample nebulized and vaporized in the nebulizer; and a mass analyzer for analyzing ions formed in the ion source, and a gas of a flow rate corresponding to the flow rate of the sample solution is mixed to the vaporized sample, and a moving direction of the sample is made opposite to a moving direction of ions at a tip of the needle electrode.

Abstract: An apparatus for detecting the minor constituents of a sample with high efficiency in positive and negative ion monitoring modes. The directions in which the sample gas is forced to flow in the ionized region within the ion source are properly switched in the positive and negative ion monitoring modes, respectively, thereby enabling both positive ions and negative ions to be detected with high sensitivity.

Abstract: A sample introduction probe for introducing a gas sample to a mass spectrometer, having an inner pipe for conducting the sample to be analyzed, and an outer pipe installed outside of the inner pipe. An opening is installed at one end of the inner pipe for enabling entry of the sample into the inner pipe. A pump is installed on a side of the one end of the inner pipe, and a probe tip heater is provided for heating the one end of the inner pipe, a heater for heating the inner pipe.

Abstract: An explosive detection system in which vapor leaking from luggage is sampled by a sampling probe, negative corona discharge is used to ionize the vapor, and a mass spectrometer is used to detect the ionized vapor, thereby judging whether an explosive is present or not.