The core principle of ICP spectrometer is to use high-temperature plasma to excite atoms in the sample to high-energy states, and then infer the types and contents of elements by detecting the characteristic spectra released during atomic transitions. The entire process can be divided into four key steps: sample introduction, plasma excitation, spectral detection, and data processing.

The first step is the sample introduction process. Whether it is a liquid, solid, or gas sample, it needs to be pre treated and transformed into a form that can be absorbed by the instrument. Liquid samples are usually directly converted into aerosols through atomizers, while solid samples need to be digested and converted into solutions. Gas samples can be directly introduced. These preprocessed samples will be sent into the plasma torch with a carrier gas (mostly argon) to prepare for subsequent excitation.

The next step is the most critical plasma excitation process. The plasma in ICP spectrometer is generated under the action of high-frequency electromagnetic field. When the high-frequency power supply is turned on, the argon gas inside the torch tube is ionized, forming a plasma torch with a temperature of 6000-10000K - a temperature far exceeding the magma temperature during volcanic eruptions, enough to break the chemical bonds of molecules in the sample and decompose them into individual atoms. Under the "baking" of high-temperature plasma, these atoms absorb energy and the outer electrons transition from lower energy levels to higher energy levels. Electrons at high energy levels are not stable and quickly return to low energy levels, while releasing light of specific wavelengths, which is the characteristic spectrum of elements. The atomic structures of different elements are different, and the characteristic spectral wavelengths released are also different, just like everyone has a unique fingerprint, which provides a key basis for element recognition.

Subsequently, these characteristic spectra will be imported into the detection system of the spectrometer. The grating in the detection system will decompose the composite light into monochromatic light, and then the photodetector will convert the optical signal into an electrical signal. Finally, computer software will analyze and process the electrical signal, determine the type of element based on the wavelength of the characteristic spectrum, calculate the element content based on the spectral intensity, and generate a visual analysis report.

From sample preprocessing to data output, the ICP spectrometer utilizes the powerful energy of high-temperature plasma to achieve precise "perspective" of elemental composition. Nowadays, it has been widely used in many fields such as geological exploration, pharmaceutical research and development, industrial quality inspection, etc., providing strong technical support for scientific research and production practice, constantly promoting human exploration of the material world.