The infrared spectrometry contains multiple information of the sample, and it is easy to be applied to on-line measurement. To Chinese medicine, this technology can improve the standard of quality control and accelerate the modernization course. In this paper, we investigate the spectral characteristics of borneol, an effective ingredient in many Chinese medicines. The following results are achieved. In middle infrared (MIR) region, utilizing the linear relationship between absorption and concentration, the concentration of borneol with relative error within 4.30% in the strongest absorption region (2950-2970 cm(-1)) is measured; in near infrared (NIR) region, the predicted concentrations of borneol are calculated by using partial least squares (PLS) regression analysis, in which the wavelengths are selected by genetic algorithm (GA) from the absorption bands of borneol in NIR region. The predicted relative error of calibration model is less than 2%. This result shows that PLS regression analysis combining genetic algorithm is a good method to improve prediction and reduce data in NIR region.
© 2005 Chinese Optics LettersPDF Article