The Study Of Chemometrics-Ultraviolet Spectroscopy On Three Isomers Of Seven Types Of Disubstituded Benzaldehyde Derivatives

Benzaldehyde derivatives are are important fine chemicals. They are widely used in the field of medicine, food and so on. Their disubstituted compounds include three isomers of o-,m- and p-. Their ultraviolet absorption spectra overlap seriously. For a mixture that contain three isomers of that, it is difficult to measure their content only using ultraviolet spectroscopy at the same time. In the study, fourteen kinds of chemometrics method were combined with ultraviolet spectrum to determine simultaneously three isomers of seven types of disubstituted benzaldehyde derivatives.In this paper, main contents and conclusions are as follows:① Through absorption spectrum of three isomers and their mixed system, linear regression line of each component, this paper analyzed the correlation among isomers; The wavelength range with different relative deviation was discussed; And the idea of IAE was introduced to represent the interference among components. At last, fourteen kinds of chemometrics method were applied to determine mixed system of three isomers on seven types of disubstituted benzaldehyde derivatives.② With regard to fluorobenzaldehyde, the IAE between two components is smaller, ultraviolet absorption spectrum of each component overlaps seriously, and the distance between linear regression line of two components is near, the mutual interference is large, the prediction effect of models is poor relatively on fluorobenzaldehyde.③ With AR of the recovery test is between 80% and 120%, the RMSEP is less than or equal to 1.0, RSD of precision experiment is less than 3.0%, the predictive effect of halogenated benzaldehyde exclude fluorobenzaldehyde is ideal using GA-K、PCR、GA-PCR、PLS、GA-PLS、GA-KF、GA-RBF. GA-PCA-RBF. To fluorobenzaldehyde, only P and GA-PCA-RBF forecast contently. To tolualdehyde, the predictive effect of all chemometrics method is bad. To hydroxybenzaldehyde, the predictive effect of all chemometrics method is ideal. To methoxybenzaldehyde, the predictive effect of all chemometrics method except GA-PCA-BP is ideal. To nitrobenzaldehyde, the predictive effect of all chemometrics method except P、GA-RBF is ideal. After calculation, their AR is between 96.0% and 104.0%, and RMSEP is less than or equal to 0.5.(4)To the same compound, the space of the wavelength range of additive property of absorbance increase as the enlargement of relative error, but the growth rate decreases. To the same relative error, the wavelength range increases firstly and then decreases when electronegativity of halogen atom weakens for halogenated benzaldehyde, and increases as the enhancement of polarity of substituent group for benzaldehyde derivatives of ortha and para position base.(5)To the same compound, the IAE increases as the enlargement of relative error of additive property of absorbance, and the growth rate reduces. For halogenated benzaldehyde, the IAE rises firstly and then falls when electronegativity of halogen atom weakens; And for benzaldehyde derivatives of ortha and para position base, the IAE rises as the enhancement of polarity of substituent group.