蟾皮提取液浓缩过程中吲哚类生物碱等多指标近红外快速检测研究

 目的采用近红外透射光谱法，进行蟾皮提取液浓缩过程中密度、含水率和吲哚类生物碱的快速检测，实现浓缩过程的状态监测和质量控制。方法采用偏最小二乘回归（PLSR）建立不同光程近红外光谱与各指标实际测定值之间的定量校正模型，并对浓缩过程中的未知样品进行预测来考察模型的适用性。结果所建立的不同光程下密度、含水率和吲哚类生物碱模型的相关系数（r）均达到0988 9，预测相对偏差（RSEP）小于10%，相对分析误差（RPD）大于3，说明模型具有较好的稳定性和预测精度。此外，2 mm光程下的密度和含水率模型优于5 mm，而对于吲哚类生物碱模型则是5 mm光程略优，可见光程对近红外光谱的影响并不是光程越长或越短越好，需要通过测试及对比分析确定。结论研究结果表明，利用近红外透射光谱分析技术可以实现蟾皮提取液浓缩过程中密度、含水率和吲哚类生物碱浓度这3个关键质控指标的同时快速检测。

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.