NIR Spectroscopy
NIR spectroscopy is the measurement of absorbed light directed on a sample in the wavelength region of 780 to 2500 nm. A non-destructive method of molecular analysis, NIR spectroscopy provides excellent quantitative data and requires little-to-no sample preparation. Some organic compounds, which tend to have complex band structures in this region, are quite identifiable in NIR spectroscopy. NIR spectroscopy can provide information on moisture, protein, fat and starch content. This spectroscopic technique is quite attractive because of its ability to produce consistent results, even as the concentration levels in a sample changes. NIR spectroscopy is commonly used in applications characterizing solid samples in the quality control of process flow and materials transport environments.
NIR spectroscopy can also be used where molecular vibrational analysis is required in the presence of interfering substances, such as glass or plastic containers, which make it ideal to perform final inspections in production lines and the laboratory. Dispersive NIR is the most common technique, which uses a spectrometer and a multi-channel detector to measure and record the NIR spectra.
NIR Spectroscopy has proven to be excellent for food and agricultural industries due to its ability to identify specific chemical bonds, such as N-H, C-H, and O-H. This provides a real quantitative tool for measuring fats, carbohydrates, fiber, proteins and moisture, which are all important measurements in food items.
NIR Spectroscopy also continues to grow as a QA/QC tool in the pharmaceutical and biotechnology markets. The technique can be applied to measure the mixing efficacy or the internal structure of a solid sample, such as a pill. It is suitable for chemists developing new compounds and as an online QA/QC tool for production. Other industries that have also accepted NIR as a satisfactory method include polymers, petrochemical and environmental industries.