Hitachi, Ltd.

Masamichi Tsukada

Toyoharu Okumoto

Konosuke Oishi

Masatoshi Kitagawa

Takashi Iino

Hayato Tobe

Yukio Okamoto

Katsuhito Harada

Yuichiro Hashimoto

Yasuaki Takada

Minoru Sakairi

Takayuki Nabeshima

Hiromi Yamashita

Masataka Koga

Taro Nogami

Kazuo Moriya

Satoshi Shimura

Akira Owada

Shouji Umemoto

Plasma ion source mass spectrometers or liquid chromatograph/mass spectrometers are provided: wherein photon noises and matrix molecule ions produced by the ion source are decreased, the decrease of the quantity of signal is suppressed, and the apparatus maintenance is improved. The photon noises are decreased with a shielding plate and a 90 degrees deflector. The maintainability in cleaning is improved by a combination of a leading electrode, the shielding plate having a small hole, and a gate valve. The decrease in the quantity of signal is suppressed with the leading electrode, and a double cylindrical type static lens. Position adjustment of the leading electrode is performed with a flat plate having plural holes. Using an ion trap mass analyzer, matrix molecule ions are eliminated by applying a resonance voltage between its end cap electrodes. Decrease in the quantity of signals, which has been a problem, can be prevented, and a high transmission can be realized with a preferable reproducibility against disturbance of an electric field caused by ion lens and the like. A detectable limit of atomic ions of the sample can be improved by eliminating the matrix molecule ions.

Mass spectrometer

A plasma ion source mass spectrometer comprising a plasma ion source,for ionizing a sample with a plasma; a mass filter,for subjecting the sample ionized by the plasma ion source,to mass spectrometry; and an interface unit,having an orifice formed in a cone,for introducing the sample ionized by the plasma ion source,into the mass filter,. Further the plasma ion source mass spectrometer comprises a first cooler,for cooling a plasma generator,of the plasma ion source,and a plasma generating power source,; and a second cooler,independent of the first cooler,, for cooling the interface unit,and for raising the temperature by changing the cooling efficiency so as to reduce the influence of deposition on the interface unit,. With this construction, the temperature of the interface unit can be controlled without changing the analysis sensitivity of the plasma ion source mass spectrometer.

Plasma ion source mass spectrometer

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

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 standard containing the same elements as a sample is prepared. Concentrations of the elements of the standard are known previously. When signal intensities of an element of the standard solution and the sample exceed an upper limit of a pulse counter of an element analyzing apparatus, a transmitting rate of a passage, through which ionized elements of the standard and the sample pass, is controlled to be less than the ordinal transmitting rate of the passage in synchronism to the passing time of the elements. The concentrations of the elements of the sample is calculated based on output signals of the pulse counter concerning the elements of the standard and the sample and known concentration of the standard.

High sensitive element analyzing method and apparatus of the same

A plasma analyzer for trace element analysis has a gas supply system comprising a plurality of gas sources, an electromagnetic valve provided on a line connecting each gas source to a plasma generating space, a buffer tank provided after the electromagnetic valve on the line, and a flow regulating flowmeter provided after the buffer tank on the line. Each electromagnetic valves is controlled for on-off operation and the corresponding buffer tank suppresses the sudden change of the flow rate of the corresponding gas, so that the composition of the gas supplied to the plasma generating space changes gradually in spite of the simple on-off operation of the electromagnetic valves. Thus, the fluctuation and extinction of the plasma attributable to the sudden change of the composition of the gas supplied to the plasma generating space can be effectively prevented.

Plasma analyzer for trace element analysis

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 spectroscopy photometer comprising: sample atomizing means for heating to atomize a sample; a plurality of light sources disposed at a like number of light flux incidence positions for causing light having required wavelengths to enter the atomized sample; means for measuring the degrees of light absorption of a plurality of elements contained in the sample by detecting the fluxes of light which have passed through the atomized sample; a plurality of holder means for holding the plurality of light sources, the plurality of light sources being larger in number than the plurality of the light flux incidence positions; and means for setting required ones of the light sources of the plurality at the corresponding light flux incidence positions by moving the holder means.

Atomic absorption spectroscopy photometer

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

A double monochrometer comprises a main monochrometer including a plane grating and an auxiliary monochrometer including a concave grating. The concave grating is disposed on the entrance or exit optical axis of the main monochrometer. Preferably, the angular dispersion of the concave grating is selected to be smaller than that of the plane grating. Sine bars for rotating the concave and plane gratings for wavelength scanning can be driven by means of a single feed screw mechanism even if the lengths of the sine bars are made different from each other in accordance with a difference in angular dispersion between the concave and plane gratings.

Growing community of inventors

Ibaraki, Japan

Masamichi Tsukada