Expert System Of Spectrophotometry

Spectrophotometry has been widely applied to various fields for its advantages, such as sensitivity, accuracy, fast velocity, simple operation and low price of instrument. However, the color-developing reactions are of a great number of influencing factors, strong uncharacteristic feature, description model and experience model for the main, and increasingly increasing literatures for new color-developing agents and new color-developing systems, so that common users and even experts usually find that it is very troublesome to select a proper color-developing reaction and method. The normal expert system is not seemingly suitable to solving the problem in this area. Therefore, at present spectrophotometric expert system is still a blank though its expected influence and significance is tremendous. Apparently, it is a tough task with big workload and many difficulties. The thinking of research work in this paper are proposed as follows on the basis of comprehensive consideration of the characteristics of expert system and spectrophotometry:(1) Based on understanding of spectrophotometry, preceding work experience and analysis for requirement of users, summarize the fundamental rules and the key effect factors of spectrophotometry, extend its function and improve its research level.(2) Based on experimental measurement and literature search, collect the "knowledge" of expert system for various kinds of spectrophotometric systems and construct a data-base suited to express "knowledge" of expert system.(3) Put forward the quantized sieving rules of spectrophotometry.(4) To aim against the biggest weakness of poor selectivity and based on the literatures and previous research work, investigate detailedly and further improve the most practical several chemometrics methods (algorithms), and entrust a multivariate quantitative analysis function to the spectrophotometry assisted by the chemometrics methods.(5) Set up a set of practical, high efficient and open expert system suited to both common users and experts.The main object for using spectrophotometric expert system of metal elements is positioned as common users who quantitatively determine concentration or content of the metal elements in various kinds of samples by using normal spectrophotometric method. Therefore, it is necessary to refine and upgrade the experiential rules to a level that can be express with quantized mathematic language. The functions of expertsystem in the ways of selection of color-developing agents and multivariate quantitative calculation were intensified in this paper. The fundamental work in the way of sample processing was also done. In this system, the database was founded by popular office software, Access 2000, and manipulated by SQL 7.0 with Visual Basic 6.0 as main software developing tool. Many works in the way of humanized design of user guide interface were done, and multifunction, overall way, facility to use and opening way of expert system were protruded, so that the expert system could be directly used by common users without any special training, even some maintenance work such as modification and addition could be also accomplished. The process of software development was extremely difficult.The information of 202 chromogenic reagents and 1202 chromogenic systems were collected, processed and turned into database. Through a comprehensive comparison and study on the effect factors of color-developing reaction, molar absorptivity ε, contrast Δλ and acidity of color-developing reaction were selected as weighting factors in consideration of sensitivity and selectivity. The weighting values of various factors were determined and confirmed for the selected representative color-developing system by comparing the systems selected with expert experience. It was found that the results recommend by expert system were in agreement with expert experience, indicating basically reach an expert level. At the same time, some information, such as the related detailed material and absorption curves were gi...