光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
Spectroscopy and Spectral Analysis
2015年
9期
2530-2535
,共6页
詹雪艳%林兆洲%孙杨%袁瑞娟%杨展澜%段天璇
詹雪豔%林兆洲%孫楊%袁瑞娟%楊展瀾%段天璇
첨설염%림조주%손양%원서연%양전란%단천선
红外定量模型%变量筛选%化学特征%变量解析%甘草
紅外定量模型%變量篩選%化學特徵%變量解析%甘草
홍외정량모형%변량사선%화학특정%변량해석%감초
Infrared quantitative models%Variable selection%Chemical characteristics%Variable interpretation%Radix Glycyrrhi-zae
借助变量筛选方法可以从复杂的光谱背景下选择部分变量构建定量预测模型,在一定程度上提高建模变量的解释性。然而模型解释性的提高并不意味着建模变量有确切的理化意义。本研究以甘草中红外定量预测模型为载体,解析移动窗口偏最小二乘(mwPLS)、组合间隔偏最小二乘(siPLS)和竞争自适应抽样方法(CARS)三种变量筛选方法所得变量与目标成分化学特征的相关性,比较不同变量筛选方法下所筛变量解释性的差异。结果表明,mwPLS 优先筛出黄酮和皂苷两类成分红外光谱上区别明显的苯环骨架振动和皂苷母核上甲基取代基弯曲振动所对应的波段,siPLS 筛出了黄酮类成分的(φ)C—O,(φ)C C=,(φ)C—H伸缩振动的特征区间组合和皂苷类成分的 C—O,C—H,O—H 伸缩振动的特征区间组合。相对于以上两种变量筛选方法,CARS 筛选得到的变量能够更好地归属于甘草苷和甘草酸在中红外1000~4000 cm-1特征区的特征峰,而且基于 CARS 筛选的变量建模,模型的预测性能得到了提高。因此,CARS 筛选的变量能实现目标成分红外特征区大部分化学特征的解析,有利于增强模型的解释性。
藉助變量篩選方法可以從複雜的光譜揹景下選擇部分變量構建定量預測模型,在一定程度上提高建模變量的解釋性。然而模型解釋性的提高併不意味著建模變量有確切的理化意義。本研究以甘草中紅外定量預測模型為載體,解析移動窗口偏最小二乘(mwPLS)、組閤間隔偏最小二乘(siPLS)和競爭自適應抽樣方法(CARS)三種變量篩選方法所得變量與目標成分化學特徵的相關性,比較不同變量篩選方法下所篩變量解釋性的差異。結果錶明,mwPLS 優先篩齣黃酮和皂苷兩類成分紅外光譜上區彆明顯的苯環骨架振動和皂苷母覈上甲基取代基彎麯振動所對應的波段,siPLS 篩齣瞭黃酮類成分的(φ)C—O,(φ)C C=,(φ)C—H伸縮振動的特徵區間組閤和皂苷類成分的 C—O,C—H,O—H 伸縮振動的特徵區間組閤。相對于以上兩種變量篩選方法,CARS 篩選得到的變量能夠更好地歸屬于甘草苷和甘草痠在中紅外1000~4000 cm-1特徵區的特徵峰,而且基于 CARS 篩選的變量建模,模型的預測性能得到瞭提高。因此,CARS 篩選的變量能實現目標成分紅外特徵區大部分化學特徵的解析,有利于增彊模型的解釋性。
차조변량사선방법가이종복잡적광보배경하선택부분변량구건정량예측모형,재일정정도상제고건모변량적해석성。연이모형해석성적제고병불의미착건모변량유학절적이화의의。본연구이감초중홍외정량예측모형위재체,해석이동창구편최소이승(mwPLS)、조합간격편최소이승(siPLS)화경쟁자괄응추양방법(CARS)삼충변량사선방법소득변량여목표성분화학특정적상관성,비교불동변량사선방법하소사변량해석성적차이。결과표명,mwPLS 우선사출황동화조감량류성분홍외광보상구별명현적분배골가진동화조감모핵상갑기취대기만곡진동소대응적파단,siPLS 사출료황동류성분적(φ)C—O,(φ)C C=,(φ)C—H신축진동적특정구간조합화조감류성분적 C—O,C—H,O—H 신축진동적특정구간조합。상대우이상량충변량사선방법,CARS 사선득도적변량능구경호지귀속우감초감화감초산재중홍외1000~4000 cm-1특정구적특정봉,이차기우 CARS 사선적변량건모,모형적예측성능득도료제고。인차,CARS 사선적변량능실현목표성분홍외특정구대부분화학특정적해석,유리우증강모형적해석성。
Feature selection can improve the interpretation of the modeling variables to a certain extent by selecting variables from the complex spectra backgrounds.However,the improvement of models interpretation does not mean that the modeling variables have the exact physical or chemical significance.In this paper,We explore the relation between the chemical characteristics of target components and the spectrum variables selected with 3 kinds of variables selection methods which are moving window par-tial least squares regression(mwPLS),synergy interval partial least squares regression(siPLS)and competitive adaptive re-weighted sampling(CARS),and compare the interpretation difference of the variables selected with the above variables selection methods.The results show that the variables selected with mwPLS accord with ν(φ) =C C of liquiritin andδCH3 orδCH2 of gly-cyrrhizin,which are the obvious spectra differences between the flavonoids and saponins in Radix Glycyrrhizae,and the variables selected with siPLS are the characteristic intervals combinations of the flavonoids or saponins in Radix Glycyrrhizae,which is the combination ofν(?) =C C ,ν(?)C—O ,ν(?)C—H of flavonoids or the combination ofνC—O ,νC—H ,νO—H of saponins while the variables se-lected with CARS can better accord with most of the characteristic peaks from 1 000 to 4 000 cm-1 of liquiritin or glycyrrhizin in Radix Glycyrrhizae,and the predict performance of the infrared quantitative model established on the spectroscopic variables se-lected with CARS can be improved.Therefore,most of the variables selected with CARS can be interpreted by the characteristic peaks in the infrared characteristic region of the target components,which is beneficial to improve the interpretation of the quan-titative model.