The integration of flame graphite furnace was realized by atomic absorption spectrometer.

Atomic absorption spectrometer can be divided into flame atomic absorption spectrometer and graphite furnace atomic absorption spectrometer according to the different ways of atomization. Graphite furnace atomic absorption needs instantaneous high current, so the technical requirements of anti-interference of the system are higher. In order to prevent the influence of graphite furnace on the whole system, the second generation atomic absorption spectrometer uses external graphite. The furnace. With the development of science and technology, every major manufacturer in the world has begun to realize a complete integrated design, which integrates all the components of spectroscopic detection system, flame, graphite furnace and heating into the main body of the same instrument, and realizes the free conversion of flame and graphite furnace. A-7000 series atomic absorption spectrometer with independent intellectual property rights has been developed. With the latest circuit design and manufacture, the integration of flame and graphite furnace has been thoroughly realized.

There are two main techniques for the determination of flame atomic absorption.

(1) Sequence multielement determination, such as A A 7003M of Beijing East-West Analytical Instrument Co., Ltd. and Spectr AA220FS of VARIAN Co., Ltd., etc. adopted the concept of ICP sequence analysis mode to realize fast sequence measurement. Its equipment cost is only 1/5 of ICP, and its running cost is lower.

(2) Simultaneous determination of multiple elements: technically, it is relatively easy to achieve the flame AAS multielement, but it is difficult to achieve the graphite furnace AAS multielement determination, so foreign manufacturers mainly seek a breakthrough here, such as Hitachi Z9000, PE SIMAA6000.

The development of multi-element simultaneous determination technology has improved the development of AAS instrumentation technology. However, due to the great progress in instrument cost, compromise conditions need to be sought in practical application. Because the measurement kinetic range of elements in AAS method is narrow, generally only two orders of magnitude, and the luminescence of multi-element lamp is strong. Degrees are generally weaker than those of single element lamps, requiring professional technical adjustment to make good use.

It is difficult to measure the concentration range of each element in the same sample at the same time in order to ensure the sensitivity of the measurement. Because flame atomic absorption spectrometry (FAAS) is a fast method to detect elements, it is of no practical significance to apply FAAS to simultaneous determination of elements in clinical practice. When using graphite furnace atomic absorption spectrometry to detect blood lead, we can use automatic sampler to improve working efficiency.

In graphite furnace atomic absorption spectrometry, the technology of graphite tube has a direct impact on the sensitivity and repeatability of the test and the service life of the graphite tube. It should be noted that the so-called "tungsten ship" is not a new technology, experimental interference is very large, can not detect high temperature elements, in the field of atomic absorption has been eliminated. At present, the most widely used one is the pyrolysis plateau graphite tube (PGT), which has good oxidation resistance, high working temperature, up to 3700 degrees C; it also has good inertia, so it is not easy to form carbides with high temperature elements (such as V, Ti, Mo) and affect atomization; it also has good mechanical strength. Its service life is obviously superior to other graphite tubes, and it can be used more than 2000 times. Batch PGT has good repeatability in detecting blood lead.

Atomic absorption spectrometer accessories