Hitachi, Ltd.

Hitachi, Ltd. Hitachi Instrument Eng.

Konosuke Oishi

Toyoharu Okumoto

Masamichi Tsukada

Masataka Koga

Katsuhito Harada

Takashi Iino

Hideaki Koizumi

Hayato Tobe

Masatoshi Kitagawa

Yukio Okamoto

Hiromi Yamashita

Makoto Yasuda

Kazuo Moriya

Yoji Arai

Tsuyoshi Nishitarumizu

Satoshi Shimura

Koichi Uchino

Seigo Kamitake

Shinji Mayama

Hideo Yamada

Masao Hashimoto

Takahashi Iino

Disclosed is a structure comprising; (a) Plasma gas is supplied to torch tube 8 from inert pressure vessel 1. (b) Nebulizer 3 absorbs sample 4 to vaporize the sample as aerosol and to introduce it into plasma 5. (c) Plasma 5 touches sampling cone 10 having an opening at the apex and a conical surface, whereby an ion stream is extracted through the opening of the sampling cone whose pressure is reduced at the rear face thereof. (d) The extracted ion stream further touches skimmer cone 12 of the conical surface having a small hole at the apex, and is absorbed into vacuum chamber 13 where the pressure is further reduced at the rear face. (e) The ion stream is flowed into quadruple pole filter 18 to carry out the mass spectrometry analysis of the ion stream.

Mass spectrometer, skimmer cone assembly, skimmer cone and its

In an analyzer in which plasma is generated, a sample is supplied to the plasma though an aerosol guide tube and analyzed by a quadrapole mass filter, the top end portion of the aerosol guide tube is made of sapphire.

Analyzer using plasma and analysis method using plasma, interface used

A plasma ion mass spectrometer capable of improving detection accuracy in mass spectrometry by reducing background noise due to ultraviolet radiation and neutral particles, and a plasma ion mass spectrometry using the same. A sample is ionized with plasma in a plasma generating portion. The flow of the ionized sample is shielded by a shield plate after an elapse of a specified time, and ions of the sample accumulated before the shielding is held in an ion trap type mass spectrometric portion for a specified time. The ions of the sample held for the specified time are then subjected to mass spectrometry. During ions of the sample accumulated before the shielding are held, ultraviolet radiation mixed with the ions of the sample disappears, and thereby only ions of the sample can be subjected to mass spectrometry. As a result, background noise is reduced, to improve detection accuracy in mass spectrometry.

Plasma ion mass spectrometer and plasma mass spectrometry using the same

A plasma mass spectrometer generates an aerosol of a sample, by dissolving the sample in a liquid solvent, and spraying the liquid into a spray chamber via a nebulizer. The solvent condenses in the spray chamber and an aerosol of the sample then passes through a supply tube to a plasma torch. Microwave power from an output on the plasma torch converts the aerosol to a plasma, and the plasma passes to an analyzer. If microwave radiation reached the spray chamber, it would cause heating of the solvent which may evaporate it so that the solvent would be present in the plasma. Therefore, there is a wall between the spray chamber and the plasma torch and microwave output which blocks such microwave radiation.

Plasma mass spectrometer

Incident slits and exit slits are provided separately on corresponding optical axes incident simultaneously on a spectroscope from a sample atomizing unit. A mechanism for changing the widths of the respective incident slits and exiting slits is provided such that the slit widths optimal to the respective elements to be measured are set on the corresponding optical axes to thereby realize high sensitivity analysis of all the elements to be measured simultaneously.

Multi-element simultaneous analysis atomic absorption spectroscopy

A mass spectrometer using a plasma ion source for analyzing an ultra-trace element includes a plasma generation system for generating a plasma including the composition of a sample, an ion beam formation system for extracting ions in the form of a beam from the plasma generating the ions, a mass spectrometry system for performing mass spectrometry of the ion beamn, and an ion detection system for detecting the ions subjected to the mass spectrometry, in which a lens system made up of a cylindrical first electrode, a cylindrical second electrode with a photon stopper disposed on the central axis thereof, and a cylindrical third electrode is further provided between the ion beam formation system and the mass spectrometry system. By the provision of the lens system, the ions generated in the plasma are transported more efficiently to the side of the mass spectrometry system and by the provision of the photon stopper in the above described position, it is achieved, with a simpler structure, to prevent photons from entering the ion detection system.

Mass spectrometer using plasma ion source

An atomic absorption spectrophotometer includes a sample-atomizing portion for ashing and atomizing a sample, a power source operable to supply electric current to the sample-atomizing portion, a controller for controlling the operation of the power source, a pair of pressure regulators for setting a flow rate of an inert gas according to an ashing step and an atomization step in the sample-atomizing portion, a pair of movable valves respectively provided downstream of and connected to the pair of pressure regulators, and a filter device provided between the pair of movable valves and the sample-atomizing portion. Either of the pair of movable valves is activated into open or closed condition in synchronism with the operation of the power source so as to select the flow rate of the inert gas into the sample-atomizing portion. An electromagnetic shut-off valve for use in the atomic absorption spectrophotometer includes a valve housing having a valve chamber, and a movable valve body housed in the valve chamber. The movable valve body is movable between open and closed positions so as to open and close a gas flow line. The wall of the valve chamber is coated with a non-metallic material.

Atomic absorption spectrophotometer and electromagnetic shut-off valve

An atomic absorption spectrophotometer comprising means for setting the ashing temperature for that of the element having the lowest ashing temperature; means for setting the atomizing temperature for that of the element having the highest atomizing temperature; and means for effecting background correction utilizing Zeeman effect.

Atomic absorption spectrophotometer and analyzing method

In atomic absorption spectrophotometers such as Zeeman atomic absorption spectrophotometer, the present invention is characterized in that the correction timing of background absorption in sample light is made to coincide with that of reference light so as to improve the accuracy of the output signals of the spectrophotometer. To accomplish this object, the present invention constitutes a calculation processing unit for storing and calculating signals by means for separating one signal consisting of sample signals and reference signals applied thereto from amplification means for amplifiying photoelectrically converted signals into sample and reference signals, and storing them, means for calculating respectively the mean values of two time adjacent signals of one of the sample and reference signals to prepare a signal of the mean values, and means for calculating the difference of the logarithmic converted values of the signals of the other of the sample and reference signals and those of the signals of the signal of the mean values at the same points of time, and obtaining correction signals of background absorption.

Atomic absorption spectrophotometer

An atomic absorption spectrophotometer is disclosed in which, in order to detect the temperature of a graphite cuvette correctly on the basis of the radiation emitted from the inner wall of the graphite cuvette, the above radiation and the measuring light emitted from a hollow cathode lamp are both taken out by the same optical members, and then the radiation is separated from the measuring light, to be detected and used for measuring the temperature of the graphite cuvette.

An atomic absorption spectrophotometer for simultaneously measuring a plurality of elements different in kind from each other. A cylindrical heating furnace is provided for heating a sample being analyzed to dry, ash and atomize the sample thereby producing atomic vapor. A plurality of hollow-cathode discharge tubes corresponding in number to the elements being detected are arranged for simultaneously emitting light beams respectively containing line spectra of the respective elements, to cause the light beams to be incident upon the heating furnace at respective angles of inclination with respect to a central axis of the heating furnace. A plurality of spectral detection systems are arranged behind the heating furnace in relation to the angles of inclination, for respectively spectral-diffracting and receiving the light beams having their respective line spectra absorbed by the atomic vapor. A signal processing device is provided for carrying out calculation to obtain concentrations or quantities of the respective elements in the sample being analyzed, on the basis of respective ratios of atomic resonance absorption of the respective line spectra spectral-detected.

In an atomic absorption spectrophotometer including an electric furnace for drying and ashing a liquid sample to be analyzed and then atomizing the sample to generate atomic vapor, a low-pressure lamp for emitting light having a spectrum of an element to be analyzed onto the atomic vapor atomized in the electric furnace, a monochromator for splitting the transmitted light from the electric furnace and selecting a wavelength of an atomic absorption line absorbed by the element to be analyzed, and a signal processing unit for performing signal processing on the light having the selected wavelength supplied from the monochromator, the electric furnace is an airtight mechanism for maintaining airtightness of the inside of the electric furnace and an evacuation unit for evacuating the inside of the electric furnace to a pressure equal to the pressure inside the lamp.

Atomic absorption spectrophotometer with furnace at pressure equal or

An absorption profile indicative of a relation in atomic absorption spectroscopy between the absorbance of a desired element and time has a constant half-width independent of the concentration of the desired element in a sample, and hence the half-width of absorption profile with respect to the desired element can be previously determined from data which is obtained by the measurement of a standard sample. In an atomic absorption spectrophotometer herein disclosed, the half-width of absorption profile is previously determined in the above-mentioned manner, and the true peak value of an absorption profile obtained by measuring a sample which contains the desired element at a high concentration, is calculated using the time width of this absorption profile at a predetermined absorbance and the previously-determined half-width.

A double polarized light beam spectrophotometer of a light-source modulation type. A modulated light beam emitted by a light source is conducted through specimen atom vapor generated by a graphite atomizer. Wavelength of light undergone atom absorption is selected and spatially separated into a pair of linearly polarized light beams perpendicular to each other. The pair of the linearly polarized light beams separated are alternately passed through a chopper and received by a photoelectric conversion device to be converted into electric signals which are utilized for determining atomic absorption of the specimen. The phase of modulation of light radiated from the light source is synchronized with phase of a current supplied to the graphite atomizer for heating thereof and the switching timing of the chopper.

Double polarized light beam spectrophotometer of light source modulation

A spectrophotometric analyzer disclosed by this invention has two monochromators capable of operating independently of each other. In each monochromator, a light beam from a light source is made to be incident on an entrance slit, and, after dispersed and wavelength scanned, issued from an exit slit as an analyzed light beam. These analyzed light beams are detected by detectors. The entrance slits and the exit slits of the two monochromators are disposed rotation symmetrically. This can simplify the operation of switching between a series mode where the analyzed light from the exit slit of the one monochromator is made to be incident on the entrance slit of the other monochromator and a parallel mode where the both monochromators operate for detection independently from each other.

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Mito, Japan

Konosuke Oishi