Hitachi, Ltd.

Hitachi-high-technologies Corporation

Hitachi Naka Instruments Co., Ltd.

Hayato Tobe

Yasushi Terui

Kazuo Moriya

Hiromi Yamashita

Masamichi Tsukada

Yoshisada Ebata

Hisashi Kimoto

Mitsuru Oonuma

Konosuke Oishi

Toyoharu Okumoto

Takayuki Wakui

Koji Yamamoto

Koichi Nakamura

Seiji Kamimura

Katsuhito Harada

Masatoshi Kitagawa

Yoshimi Kasai

Yoichi Sato

Hiroyasu Ishida

A spectrophotometer includes: a sample-chamber lid capable of opening and closing an opening portion of a sample chamber for setting a sample and a reference sample; and sample-chamber lid opening-closing detecting means for detecting an opening-closing state of the sample-chamber lid, and the spectrophotometer is capable of controlling a measurement of a xenon flash tube as a light source, a spectroscope, a detector, an amplifier, an AD converter, a processor, a storage device, and a data display part. In the spectrophotometer, the light source is turned on after a state of the lid changing from an opening state to a closing state is detected in a sample-setting instruction state by the sample-chamber lid opening-closing detecting means; absorbancy, transmissivity, reflectivity, a sample-side energy value, or a reference-side energy value is measured; and a measurement result is displayed on the data display part.

Spectrophotometer

A spectrophotometer includes a xenon flash lamp, a spectroscope, and a light detector, wherein the spectrophotometer is configured to arrange a low-pressure mercury lamp on a bundle of light rays between the xenon flash lamp and the spectroscope on an as needed basis upon a performance determination of the spectrophotometer, and has a shutter mechanism that switches between shielding the bundle of light rays emitted from the low-pressure mercury lamp and allowing the bundle of light rays to pass through. A processing unit determines the performance of the spectrophotometer by detecting each of the light intensities with the light detector at the time when shielding the bundle of light rays and at the time when allowing the bundle of light rays by operating the shutter mechanism.

Spectrophotometer and method for determining performance thereof

A main unit, a lamp chamber, a graphite furnace analyzing section, a flame analyzing section, and a flame gas controller are sequentially placed from right to left. An autosampler is placed on the top of the lamp chamber. A housing section for a transformer and a power supply unit is provided behind the lamp chamber, the graphite furnace analyzing section, the flame analyzing section, and the flame gas controller. The housing section is used as a space for a power unit used for the whole atomic absorption spectrophotometer, as well as the graphite furnace analyzing section. The housing section is also used as space for a circuit board for controlling the whole atomic absorption photometer. The autosampler has a quadrangular sample tray. The autosampler drives an arm for holding an aspiration needle in the left and right directions and also in up and down directions.

Atomic absorption spectrophotometer

An atomic absorption spectrophotometer possessing an electrical heating unit which includes a graphite tube for atomizing a sample by heating the sample; a light emitting unit for emitting measuring light and irradiating the atomized sample with the measuring light; a spectroscope unit for diffracting the measuring light passing the electrical heating unit and selecting the required wavelength component; a detection unit for detecting the quantity of the required wavelength component selected by the spectroscope unit; an input unit to input at least one of the wavelengths of the required wavelength component and the required heating temperature of the electrical heating unit; and a control unit for controlling the above units, which comprises a shading device provided at the propagation axis of the measuring light between the electrical heating unit and the detection unit, and which possesses a light transmitting unit, for restricting the quantity of the measuring light passing the electrical heating unit, with the area of the light transmitting unit being changeable; and wherein the area of the light transmitting unit in the shading device is changed according to the set measurement conditions.

The object of this invention is to provide an atomic absorptiometer and a metal specimen atomic vapor generation apparatus used in the atomic absorptiometer, which enable a light absorption measurement based on the Zeeman effect highly capable of background correction and eliminate the need for the troublesome work of dismounting a magnet. For this purpose, the following configuration is employed. First, the specimen, hydrochloric acid, and sodium borohydride are delivered and mixed by the peristaltic pump 10 to produce a metallic hydride. The generated gas-liquid mixture solution is separated by the separator 12 into a specimen gas and liquids. The separated specimen gas is introduced into the heating section 30. Electricity is supplied from the power source 28 to the specimen heating section 30 where the specimen gas introduced is heated and separated into hydrogen and a specimen metal vapor to be measured. The specimen metal vapor is then introduced into the measuring section 34 arranged between magnetic poles of the magnet 32 where the metal vapor is subjected to the atomic absorptiometric analysis based on the Zeeman effect.

Atomic absorptiometer and a metal specimen atomic vapor generation

The invention intends to provide an atomic absorption spectrophotometer which can establish a uniform heat distribution during heating of a sample and can improve analysis accuracy and analyzing efficiency. For this purpose, a graphite tube type cuvette mounted in a graphite atomizer furnace for an atomic absorption spectrophotometer comprises a large-diameter portion for retaining a sample in place, a small-diameter portion connected to the large-diameter portion and having a smaller diameter than the large-diameter portion, and a step portion for demarcating between the large-diameter portion and the small-diameter portion. The graphite tube type cuvette is formed such that its cross-sectional area in a plane perpendicular to the direction of passage of an electric current supplied to the cuvette is the same in any of the large-diameter portion, the small-diameter portion and the step portion. The amount of resistance heat is thereby also the same in any portions.

Atomic absorption spectrophotometer and graphite tube type cuvette used

In an analysis device, an auxiliary gas supplied from a compressor 1 is introduced from an auxiliary gas inlet 3 via a pipe 2 to a burner through a pressure regulator 5, a pressur meter 6, a pressure switch 7 and a connecting joint 8. On the other hand, a combustible gas supplied from a gas bomb 9 is introduced from a combustible gas inlet 11 via a pipe 10 to the burner through a first electromagnetic valve 12, a pressure regulator 13, a pressure meter 14, a needle valve 15, a second electromagnetic valve 16 and a connecting joint 17 and further via a tube. An auxiliary gas use block 4, on which auxiliary gas flow controlling elements such as the pressure regulator 5, the pressure meter 6 and the pressure switch 7 are secured, is provided independent and separated from a combustible gas use block 18, on which combustible gas flow controlling elements such as the first electromagnetic valve 12, the pressure regulator 13, the pressure meter 14, the needle valve 15 and the second electromagnetic valve 16 are secured. Whereby the analysis device using chemical combustion flame having an element safety is provided in which possible danger caused by such as the gas leakage and the gas mixing between the combustible gas passage and the auxiliary gas passage is further reduced.

Analysis device using chemical combustion flame

A light beam emitted by a hollow cathode lamp is concentrated on a central portion of an electrothermal sample atomizing apparatus by a concave mirror. The light concentrated on the central portion of the electrothermal sample atomizing apparatus is further concentrated on a central portion of a flame produced in a burner type sample atomizing apparatus by a lens. The light traveled through the burner type sample atomizing apparatus is condensed by a concave mirror, reflected by a flat mirror, and concentrated on an entrance slit of a spectroscope. Light outgoing through an exit slit of the spectroscope is detected by a photodetector.

Atomic absorption spectrophotometer and atomic absorption

Atomic absorption spectrometer

A sample disposed in a graphite tube in a furnace is subjected to thermal treatment at successive stages, drying, ashing and atomization and atomic absorption due to an element contained in the sample is measured. Amounts of inert carrier gas supplied to the graphite tube are different for different samples. The carrier gas flow rate at each of the stages is varied so as to reduce influences of background when each of the samples is treated. The carrier gas flow rate is varied, depending on the magnitude of a background signal measured on the basis of light which has passed through the graphite tube.

Atomic absorption analyzing apparatus with adjustable carrier gas flow

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

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.

Growing community of inventors

Mito, Japan

Hayato Tobe