Expert systems for chemical analysis (ESPRIT Project 1570)

Summary This paper gives an overview of the structure and processes going on in the project Expert Systems for Chemical Analysis (ESCA), an international project within the ESPRIT research programme of the European Community. The application area, HPLC method development, is explained and broken down into four domains. The methods used for representing knowledge in the project are discussed.     

A chemometric tool for computer-aided decision making in analytical laboratory management

One of the tasks of management in analytical laboratories is the scheduling of analyses and the organization of the laboratory resources with respect to the workload. By a simulation of the laboratory operations, one can describe and eventually forecast the magnitude of the sample backlog and result delays with respect to the followed strategy to schedule samples and resources. However the design and validation of a simulation model is a lengthy and expensive task, requiring the help of a specialist in the area of operations research. In this paper an expert system is described that guides the laboratory manager through the various stages of the model design. The output of the expert system is a simulation model written in program code (SIMULA) that after compilation can be used to simulate the laboratory.     

Strategies in molecular spectroscopic analysis with application of queueing theory and digital simulation

Waiting lines in a laboratory for molecular spectroscopie analysis are simulated by digital methods. The influence of several parameters, such as the mean analysis time, the mean inter-arrival time of the samples and the routing procedure are evaluated by application of queueing theory. The queues were treated as a sample realization from a stationary first-order autoregressive system. The structure of the time series of the number of waiting samples in the model was identical to the time series observed in a real laboratory. The possibilities of digital simulation for decision-making in analytical laboratories.are demonstrated.     

An expert system for designing an intelligent spreadsheet for evaluation of precision of liquid chromatographic methods

Method validation is increasing in importance as higher standards of precision and accuracy are required. The validation of liquid chromatographic methods requires the examination of selectivity, sensitivity, accuracy, precision and limitations, depending on the purpose of the method. The precision is affected by the repeatability of procedural steps (e.g., injection), within the method and by its overall reproducibility (e.g., interlaboratory reproducibility). The application of spreadsheets with an expert system to evaluate these effects is described. The spreadsheets are programmed to produce the necessary statistics. Rules are defined for the expert system to interact with these to select suitable tests for different applications, to set up spreadsheets into which the analyst inputs the data, and to interpret the data processed in the spreadsheet. The system is tested with a repeatability study of the separation of aspirin and salicylic acid. A combination of the Goldworks software for development of expert systems and the Lotus 1-2-3 spreadsheet package was used.     

Some considerations on batch arrival and batch analysis in analytical laboratories

The mean delay of analytical results is an important parameter in the performance of analytical laboratories. The modes of sample arrival and processing influence that delay. By the application of queueing theory and digital simulation, the effects of batch arrival and batch processing on the delay are estimated.     

Cheometrics in the daily laboratory practice

Summary Developments in computing technology have drastically changed the way analyses are performed in the analytical research and routine laboratory. More complex calculations are possible on data measured by microcomputer controlled instruments. Moreover affordable hardware and software became available for the development and implementation of knowledge based systems, which are an important tool to tackle problems which can not be solved in an algorithmic way. As the extraction of relevant analytical information from large and complex data structures became more accessible, instrument development was further pushed in the direction of higher complexity of operation and data.Chemometrics and, recently, knowledge engineering, have produced tools to support the analyst at various stages during the analysis; method development, calibration, optimisation, signal processing and method validation.Apparently these tools are becoming the building blocks of intelligent analytical workstations arranged in the socalled intelligent laboratory.By a system analysis of the activities in an analytical laboratory, the functionalities of the intelligent laboratory are discussed. Furthermore, the current status of the intelligent laboratory is evaluated in terms of available systems, systems expected to become available in the near future and black spots are identified for which no tools are yet available, requiring more chemometrics input.This overview comprises aspects of method development, the validation of analytical results and the processing of these results into information. Examples are chosen from the intelligent chromatography and intelligent spectroscopy laboratory.     

i‐Chemometrics

When I was a young scientist, it was rare for me to read publications that were over 10 years old. How does one know what interesting information lies in publications older than oneself? A great deal of people investigate the roots of their family, likewise a scientist may also be interested in the roots of their science. This account attempts to achieve both: to provide some direction toward old and interesting literature and to share my passion of Chemometrics. Copyright © 2015 John Wiley & Sons, Ltd.     

An expert system for the choice of factors for a ruggedness test in liquid chromatography

Method validation is an important and costly step in the development of liquid chromatographic methods, especially for pharmaceutical samples. A ruggedness test is valuable for finding the analytical conditions which give the best performance. By varying the factors that influence method performance, it is possible to design a more rugged method before a study of reproducibility is started. The choice of the factors to test is important. An expert system is described for the selection of factors in ruggedness tests. The system proved satisfactory for 10 of the 11 cases of pharmaceutical formulations tested.