| Chemometrics is an interdisciplinary subject. It includes statistics,mathematics and mathematical statistics. In recent years, with thedevelopment of computer science, more and more people attach importanceto chemometrics. Multi-components simultaneous determinations in thecomplicated analytical system, without chemical separation, are the mainresearch objects of analytical chemists, which is also a fast developingresearch field in chemometrics. In this dissertation, double artificial neuralnetwork analysis-UV visible spectroscopy method was used to simultaneousdetermination of aesculin and aesculetin in Chinese herbal medicine-CortexFraxini, and Kalman Filter analysis flow-injection chemiluminescence(FI-CL) method was developed to simultaneously determine trace amountsof niobium and tantalum in geological samples. The main research work isdescribed as follows.1. Simultaneous determinations of aesculin and aesculetin in Chineseherbal medicine-Cortex Fraxini by double ANN and Uv-vis.A Chinese herbal medicine always concludes many chemical components,which is a typically complicated system. The analytical methods are usuallyHigh Performance Liquid Chromatography (HPLC) and Thin LayerChromatography (TLC).The former method suffers from high-costinstrument, complex operation, and long-time analysis, and the latter one ispoor recurrence. HPLC can provide an effective method to determinecomponents in Chinese herbal medicine. However, it will not take effectwithout compared samples which is expensive. In this article, we attemptedto analyze the UV-vis data of Chinese herbal medicine by the improveddouble ANN, and realized the simultaneous determination of maincomponents by self-learning, self-revision and self-fit, without the boringprocess of separation.The revised double ANN, based on the traditional artificial neural network,adds the function of self-distinguishing and self-fit, and provides the basisof selecting the learning samples. The calculating process includes twonetworks. (1) Learning network. In this section, ANN predicts components'content, using the net parameters gotten by any learning sample. (2) Fitnetwork. Take the components'content as the input value of the fit network,and regard the absorbency value as the standard value to start the learningprocess until the relative error between the experimental value andpredictive value(Uv) is smaller than the admitted number. It has beenproved that the combined method of double ANN and UV-vis cansimultaneously determine aesculin and aesculetin in Cortex Fraxini. Thedetermination accuracy was above 91.0% when the admitted relative errorwas 15%.Because of the complexity, the Chinese herbal medicine always includesmany components. Therefore, other interference components will influencethe determination. To solve this problem, we first put forward the virtualcomponents elimination method. The purpose is adding an unknown valueto the learning samples, and making it to involve the learning and fit process.If the Uv value is larger than the admitted error (E), adjust the value ofvirtual component, and continue to learn and calculate in double ANN.when the Uv value is smaller than E, ANN will forecast the results andreport them.In addition, the precision of double ANN was tested. The determinationprecision of aesculin and aesculetin was 1.0% and 0.7%, respectively. Thecombination of double ANN and the virtual components elimination method,without the separation, can successfully determine effective components inChinese herbal medicine.2. Fast simultaneous determination of niobium and tantalum byKalman Filter analysis with flow-injection chemiluminescence method.Niobium (Nb) and tantalum (Ta) are widely known to be extreme similar inchemical characteristics, which results in a difficulty to separate anddetermine them. Although inductively coupled plasma mass spectrometry(ICP-MS) is convenient for the simultaneous determination of Nb(V) andTa(V), it is not suitable for field scene analysis. Therefore, there is a strongrequirement for a simple, fast and effective method to determine trace Nb(V)and Ta(V) in order to meet the need of field scene fast analysis.Flow-injection chemiluminescence (FI-CL) is an available trace-analysistechnique. However, the fatal disadvantage of the chemiluminescencemethod is its poor selectivity, which makes it difficult to differentiate thechemiluminescence signal of Nb(V) and Ta(V). The general method is...
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