AAS atomic absorption spectrophotometer

AAS atomic absorption spectrophotometer, also known as Atomic Absorption Spectrophotometer, is a high-precision analytical instrument based on the principle of atomic absorption spectroscopy, widely used in various fields such as chemistry, environment, food, medicine, geology, metallurgy, materials science, etc.

Instrument principle

The core principle of AAS is the selective absorption of characteristic electromagnetic radiation by ground state atoms. When a specific wavelength of light emitted by a light source passes through the atomic vapor of the element under test, the ground state atoms in the vapor will absorb the light of that wavelength. The absorption intensity follows Lambert Beer's law, which states that the absorbance is proportional to the concentration of the ground state atoms, thus achieving quantitative analysis. The resonance absorption line of each element has a unique wavelength, like the "fingerprint" of the element, which is the basis of AAS selectivity.

Instrument composition

AAS mainly consists of four parts: light source, atomization system, optical system, and detection system. The light source usually uses a hollow cathode lamp, which can emit characteristic sharp line spectra of the tested element; The atomization system includes a flame atomizer and a graphite furnace atomizer. The former uses a flame to atomize the sample, while the latter atomizes the sample through high-temperature heating; The optical system consists of a monochromator, a slit, and a lens, which are used to separate the characteristic spectral lines of the tested element and eliminate interference; The detection system converts the optical signal into an electrical signal, amplifies it, and displays the result.

Instrument Features

AAS has the advantages of high sensitivity, good selectivity, wide linear range, and easy operation. Its sensitivity can reach the picogram (pg/mL) level, suitable for the analysis of trace elements; Due to the unique characteristic spectral lines of each element, AAS can accurately distinguish different elements and avoid interference; Meanwhile, AAS has a wide linear range and can maintain good linear relationships over a large concentration range, making it suitable for analysis of various samples.

Application field

AAS is used in environmental monitoring to determine the heavy metal content in water quality, soil, and atmospheric particulate matter; Used in food testing to analyze the mineral content in food additives, agricultural products, and health products; Used in the pharmaceutical field to determine metal impurities in drugs and metal elements in biological fluids; In the fields of metallurgy and geology, it is used to analyze the elemental composition of metal alloys and ores.