[Determination of isorhamnetin in Hippophae rhamnoides Linn from West Sichuan plateau using near infrared diffuse reflectance spectroscopy].

The objective of this study was to develop a method for the determination of isorhamnetin in Hippophae rhamnoides Linn from West Sichuan plateau using near infrared diffuse reflectance spectroscopy. Applying the method of mixing with SiO2, the near infrared spectra (NIS) with the range of 12 000-4 000 cm(-1) were recorded for the Hippophae rhamnoides Linn containing isorhamnetin with the content of 0.1%-0.8%. Calibration models were established using the PLS (partial least squares). Different spectra pretreatments methods were compared. The study showed that spectral information can be extracted thoroughly by constant offset elimination (COE) pretreatments method with the correlation coefficient (r2) of 0.739 8, SEC of 0.107 (standard deviation of the calibration sets) and SEP of 0.073 (standard deviation of the prediction sets). The results indicate that near infrared diffuse reflectance spectroscopy is more rapid and convenient than conventional methods.