Simultaneous Determination Butene Diacid And Tolualdehyde Isomers By Chemomtrics Methods-Uitraviolet Spectrophotometry

It is always hot and difficult problem in the analytical chemistry to establish a method for simultaneous determination isomers. At present, the analytical technologies with a separably performance are adopted to determinate isomers, such as chromatography, combination method with Gas chromatography and mass spectrometry, capillary electrophoresis, et al. But the prices for those instruments are expensive, and the operations for those methods are fussy. If solving this problem by ultraviolet spectrophotomety of convenient operation and low price, not only does it play an important role in acadamic reasearch, but also makes sense of controling production quality in industry and instructing the production.Chemometrics is an interdisciplinary subject. It includes statistics, mathematics, computer science and chemistry. In recent years, with thedevelopment of computer science, more and more people attach importance to chemometrics. Multi-comnonents simultaneous determinations in the complicated analytical system,without chemical separation,are the main research objects of analytical chemists,which is also a fast developing research field in chemometrics.In this paper,Partial least square(PLS),Kalman Filter (KF),artificial neural network(ANN)were applied to determination of o-,m-and p-tolualdehyde and cis-Butene diacid and trans-Butene diacid by ultraviolet spectrophotometry.The main research work is described as follows.1.The calibration models were established for determination of o-,m- and p-tolualdehyde and cis- and trans-Butene diacid by partial least squares(PLS) and ultraviolet spectrophotometry after optimize the Chemical condition of determination,the composing of calibration set and the parameter of Partial least square(PLS)regression.The proposed method was applied to determination three batches of trans-Butene diacid samples,by statistical signification test,and the results of determination were compared with those of HPLC with no signification difference at 0.05 level.Besides,the proposed method was also applied to determining three tolualdehyde isomers.The effect of three isomers with different concentration ratio on the accuracy of determination results was discussed and the appropriate range of concentration ratio was found.The determination results of three isomers in simulating samples were satisfactory.2.The absorption spectra datas of the mixture of cis-and trans-Butendioic acid and the mixture of three tolualdehyde isomers in chapter 2 were possced by Kalman Filter(KF).The calibration models were established for determination of o-,m- and p-tolualdehyde and cis- and trans-Butene diacid by Kalman Filter and ultraviolet spectrophotometry.The proposed method was applied to determination three batches of trans-Butene diacid samples.The cis-Butene diacid results of determination were accorded with those of HPLC and the cis-Butene diacid results of determination were worse.Besides,the proposed method was also applied to determining three tolualdehyde isomers.The correlation coefficients of the models were 0.9893,0.9624 and 0.9938, respectively.The mean recoveries of replicate analysis of three simulating samples were 82.72%,99.62%and 81.63%,which were not satisfying.3.The absorption spectra datas of the mixture of cis- and trans-Butene diacid and the mixture of three tolualdehyde isomers in chapter 2 were possced by artificial neural network(ANN).The calibration models were established for determination of o-,m- and p-tolualdehyde and cis- and trans-Butene diacid by artificial neural network and ultraviolet spectrophotometry.The proposed method was applied to determination three batches of trans-Butene diacid samples.The cis-Butene diacid results of determination were accorded with those of HPLC and the cis-Butene diacid results of determination were worse. Besides,the proposed method was also applied to determining three tolualdehyde isomers.The determination results indicate that ANN could predict unkonwn analyte concentrations with satisfactory results.In addition,the effect of three isomers with different concentration ratio on the accuracy of determination results was significative.Thus,ANN was applied as a powerful tool for the simultaneous determination of the analyte.4.At last,the capacities of PLS,FK and ANN in resolving overlapped peaks were compared.The appropriate chemometrics method for determinating different mixture of isomers was pionted out.