Multi-pathlength method to improve the spectrometric analysis accuracy based on “M + N” theory
Multi-pathlength method to improve the spectrometric analysis accuracy based on “M + N” theory
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DOI：
10.1039/c6ra04323b
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发表时间：
2016-04
期刊：
影响因子：
3.9
通讯作者：
Gang Li;Luo Yongshun;Zhe Li;Li Zeyun;Ling Lin
中科院分区：
文献类型：
--
作者：
Gang Li;Luo Yongshun;Zhe Li;Li Zeyun;Ling Lin
在近红外光谱分析中，光程长度是一个特殊的因素。它是一个与样品浓度相似的物理变量，是与样品池的几何尺寸偏差、光源安装误差和入射光纤相结合的变量。光程变化引起的准确度下降是定量光谱分析中的一个难题。“M+N”理论是将影响测量精度的量分为M个因素和N个因素的测量理论。在理论界定的基础上，提出并分析了N因素的理论内涵和三种应用方法。M+N理论为解决N因素对测量精度的负面影响提供了一套指导思想。为了验证三种应用方法的有效性，分别用单光程和多光程模型对脂类的浓度进行了预测实验。实验结果表明，多路径长度的预测精度高于单路径长度的预测精度。实验结果还表明，校准集的分布应该大于预测集的分布。在这种情况下，预测精度将得到显著提高。内涵为测量提供了依据，可采用N因子三种方法来提高定量光谱分析的准确度。采用多光程长法建模，减少了样本库更换和仪器安装带来的误差。
The pathlength is a special factor in near-infrared (NIR) spectroscopy analysis. It is a physical variable that is similar to the sample concentration, and is a variable combined with the geometric dimension deviation of the sample pool, installation error of the light source and incident optical fiber. The decrease of accuracy caused by the pathlength changes is a difficult problem in quantitative spectrometric analysis. The proposed “M + N” theory is a measurement theory in which the quantity impacting the measurement accuracy is classified as M elements and N factors. The theoretical connotation and three application methods of N factors are proposed and analyzed based on the definitions of the theory. “M + N” theory provides a set of guidelines to find a variety of ways to solve the negative impact of N factors on the measurement accuracy. In order to verify the effectiveness of three application methods, an experiment was done to predict the concentration of intra-lipids by single pathlength and multi-pathlength modelling. The experimental results showed that the prediction accuracy of the multi-pathlength was higher than that of the single pathlength. The experimental results also showed that the distribution of the calibration set should be larger than that of the predication set. In this case, the predication accuracy will be improved significantly. The connotation provides a basis for the measurement, and three methods of N factors can be used to improve the accuracy of quantitative spectrometric analysis. Using the multi-pathlength method to build a model, the errors caused by the replacement of the sample pool and instrument installation are decreased.