Chemometric analysis in quantitative near-infrared spectroscopy.

摘要

This study describes chemometric methods and their use in quantitative near-infrared (NIR) spectroscopy, and NIR instrumentation. The particular application studied was the NIR analysis of nicotine chewing gum containing nicotine at the 0.4% level using both transmittance and reflectance near-infrared spectrophotometers. The gum tablets were scanned in a sample holder specially designed for this study and a specific HPLC method was developed to determine the true potencies of the nicotine tablets after they were scanned on the NIR spectrophotometer. The calibration set was constructed from using the NIR and HPLC data, which was used to predict the nicotine content of unknown samples. The potencies of the unknown samples were further determined by the HPLC method and the HPLC results were compared to those obtained from NIR. Different calibration techniques, including simple linear regression, multiple linear regression, and partial least squares regression, were investigated and their effects were discussed. In addition, the techniques for detection of outliers and different mathematical sample pre-treatments were explored.