What is the principle of atomic absorption spectroscopy

What is atomic absorption spectroscopy? Many people may not know much about it, and many people do not pay much attention to the application of this technology in daily life. Therefore, the following is a comprehensive analysis and introduction of the principles of atomic absorption spectroscopy. I hope that after learning the following, you will be able to use them more scientifically.

Principles of Atomic Absorption Spectroscopy

The content of the element to be measured is determined based on the degree of absorption of the characteristic spectral lines of the element by the ground state atoms in the sample.

Atoms are usually in their ground state.

When characteristic radiation passes through atomic vapor, ground state atoms absorb energy from the radiation and transition from the ground state to the excited state.

When characteristic radiation passes through atomic vapor, ground state atoms absorb energy from the radiation and the outermost electrons jump from the ground state to the excited state.

The degree of light absorption by an atom depends on the concentration of ground state atoms in the light path. In general, it can be approximated that all atoms are in the ground state.

Therefore, the content of the element to be measured in the sample can be determined based on the degree of attenuation after the light is absorbed.

This is the theoretical basis of quantitative analysis by atomic absorption spectrometry.

Rationale

Atomic absorption spectroscopy is based on the fact that the ground state atoms of the element being measured in the gaseous state have a strong absorption effect on the atomic resonance radiation of the element. This method has the advantages of low detection limit, high accuracy, good selectivity and fast analysis speed.

When the experimental conditions such as temperature, absorption path, and injection method are fixed, the ground state atoms of the element to be measured produced by the sample absorb the monochromatic light radiated by the hollow cathode lamp of the element as a sharp line light source, and its absorbance (A) is proportional to the concentration (C) of the element in the sample. That is, A=KC, where K is a constant. Based on this, by measuring the absorbance of the standard solution and the unknown solution, and knowing the concentration of the standard solution, a standard curve can be drawn to find the concentration of the element to be measured in the unknown solution.

This method is mainly suitable for the analysis of trace and trace components in samples.

Atomic absorption spectrometers can be divided into single-beam spectrometers and double-beam spectrometers in terms of structure.

The above is an analysis of the principles of atomic absorption spectroscopy. I hope that after these analyses and introductions, everyone will be able to pay attention to these issues. In daily life, everyone should have a better understanding of these common sense, because only with a more comprehensive understanding of these issues can we use this thing correctly.