Rapid and Quantitative Determination of Multiple Quality Indicators(Indole alkaloids,etc.) in Concentration Process of Bufo bufo gargarizans Cantor Extract Using Fourier Transform Near Infrared Spectroscopy and Chemometrics

OBJECTIVE To investigate the application of near infrared spectroscopy in rapid and quantitative determination of multiple quality indicators in concentration process of Bufo bufo gargarizans Cantor extract.METHODS NIR transmission spectra of concentrated solutions were collected in rectangular quartz cuvette with different optical pathlengths(2 and 5 mm).Calibration models of density,water content and indole alkaloids were developed by partial least squares regression(PLSR).The established models were applied to predict the unknown samples to test the performance of the models.RESULTS The correlation coefficients of the density,water content and indole alka.The residual predictive deviations(RPD) were all above 3,and the relative standard errors of predictions(RSEP) were less than 10%,indicating the satisfactory model performance and predictive ability.Moreover,better calibration results were obtained with an optical path length of 2 mm for density and water content,and 5 mm for indole alkaloids.The results revealed that the optical path length has influence on the NIR analysis results,and the appropriate path length for the NIR analysis should be determined by comparison analysis.CONCLUSION NIR spectroscopy technique provides a novel efficient and environmental friendly approach for the fast simultaneous determination of three key quality indicators(density,water content and indole alkaloids) in the concentration process of Bufo bufo gargarizans Cantor extract.