Visible/near-infrared spectroscopy refers to electromagnetic waves with wavelengths in the range of 400-2500 nm. When the substances are irradiated, some functional groups generate vibrations and rotational state changes or energy level transitions, and absorb energy, resulting in changes in the spectrum. The functional groups that absorb in the near-infrared region are mainly C-H, 0-H, SH, and N-H. The number and structure of these groups in the material are different, and corresponding information is generated in the near-infrared transmission or reflection spectrum. Using quantitative chemical analysis methods, the information contained in the spectra can be mined. Based on this, the content, physicochemical properties, and other index characteristics of the test substances can be studied, and the main chemical components of the main chemical components rich in crops, soils, foods, etc. can be studied. For C-H, 0-H, SH, N-H keys, therefore. The visible/near-infrared detection technology can be widely used in the quality analysis of various foods and agricultural products. It can quantitatively and qualitatively analyze the quality of plants, soils, fruits, and various agricultural products. It has the advantages of fast analysis, stability, accuracy, and sample preparation. Simple and small, no damage, follow-up use of low cost, energy saving and environmental protection features, is rapidly replacing many conventional physical and chemical analysis methods.
In the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, near-infrared spectroscopy is considered to be one of the most valued and promising methods for the application of analytical chemistry and analytical instruments.