Computers in Quantitative TL-Chromatography

Abstract

The paper presents a discussion of the use of computers, mainly of the micro-processor variety, in devices for the photometric quantitation of TL-chromatograms. First a brief survey is given of the principal features of contemporary photometers specifically designed for chromatographic applications. The most sophisticated and expensive of these are dual wavelength instruments and at the present state of development only these have as yet been computerized. It is, however, anticipated that in the near future the use of computers will spread also to the less sophisticated single wavelength devices with a moderate price tag. The advantages are ease of operation as well as superior performance characteristics. The former is achieved using a computer to control the internal operation of the photometer and some of the possibilities open in this regard are discussed. The improvement in performance is achieved in a different way. Photometric quantitation of TL chromotograms requires a number of mathematical operations upon the signal on its path between the light source and the output display. The computer permits the use of almost any kind of signal transforms, transforms which would be completely impractical to carry out by traditional techniques. The acquired and preprocessed signal, which in a conventional device would be directly fed to the output recorder, can be subjected to “after-processing” with a substantial further gain in performance. The results obtained by computerized analysis are available in alpha-numerical form. Both hard and soft copy devices can be used. If desired a graphical display in analog form can also be obtained. The output information provided by the computer can be stored in extremely compact form on magnetic tape or disc with very fast access and retrieval.     

New Applications of Computers in Chemistry

The mathematical model of constitutional chemistry described here is based on a concept of isomerism which has been extended from molecules to ensembles of molecules. A chemical reaction is the conversion of an ensemble of molecules into an isomeric ensemble. An ensemble of molecules is representable by an atomic vector and an associated bond and electron (BE)- matrix, and a reaction by a reaction (R)-matrix. These BE-and R-matrices serve as a basis for computer programs for the deductive solution of chemical problems. We present here algorithms and computer programs based on the theory of BE- and R-matrices. They enable the classification and documentation of structrues, substructures and reactions, the prognosis of reaction products,the design of syntheses, the construction of networks of mechanistic and synthetic pathways and the prediction of chemical reactions.     

Organic Synthesis in the Age of Computers

The computer affords four areas of interest to synthetic chemists: (1) storage and retrieval of information; (2) complex calculations of shape and reaction dynamics; (3) artificial intelligence (AI) to solve synthetic and analytical problems; (4) overall direction of multiple laboratory experiments. Our work began 30 years ago initiating molecular geometry calculations to match experimental results. The explosive growth of computer power since will be illustrated. Synthesis design (as AI) requires an efficient protocol to search huge trees. The SYNGEN program is based on simplification and systematization, first of skeletal dissection, then of structure and reaction characterization, for generation of optimal synthesis routes. The program will be be described and its future development outlined. Finally, a perspective on the future of all four areas will be sketched, noting the necessary attendant growth in systematic use by chemists and in sympathetic interfaces by software designers.     

从原子到大分子体系的计算机模拟——计算化学50年

本文综述并修订了从20世纪50年代末至今,我们在计算化学领域所做的一些有意义的工作。序言部分把我们的工作置于当代科学的背景之下。然后我们以一种经典的基准测试体系——一种新的单粒子表象（即替代传统的原子和分子自旋轨道的化学自旋轨道）所构建的氢分子（H2）波函数——作为开始。用Hartree-Fock-Heitler-Lo...     

Microcomputers in the laboratory

Zusammenfassung Im vorliegenden zweiten Teil der dreiteiligen Übersicht über den Einsatz von Mikrorechnern im Laboratorium werden die Hilfsmittel vorgestellt, die für die Herstellung funktionsfähiger Programme zur Verfügung stehen.

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Microcomputers in the laboratoryII. Software

Summary In the present second part of the three-part review on microcomputers in the laboratory available aids are discussed for preparing efficient programs.

I. Mitt.: Fresenius Z. Anal. Chem. 296, 18 (1979)     

Traceability in laboratory medicine

In laboratory medicine meaningful measurements are essential for diagnosis, risk assessment, treatment and monitoring of patients. Thus methods applied in diagnostic measurements must be accurate, precise, specific and comparable among laboratories. Inadequate or incorrect analytical performance has consequences for the patients, the clinicians, and the health care system. One key element of metrology is the traceability of a measurement result to the SI system ensuring comparable results. This principle is described in the ISO/TC 212/WG2 N65 prEN 17511 Standard. In addition to the principles of metrology, the clinical usefulness, the diagnostic needs, and the biological and disease associated variations in patients' specimens have to be considered when the analytical biases for diagnostic purposes are defined. It must be the general goal of diagnostic laboratories to produce results that are true and comparable worldwide. The recent European in vitro diagnostic (IVD) Directive 98/79 EC follows the above mentioned standard of the International Organization for Standardization (ISO) and the European Committee for Standardization (CEN) requesting its application for all IVD reagents used within the European Union. This new European legislation will have a worldwide impact on manufacturers and clinical laboratories and will be implemented in 2003. It states that "traceability of values assigned to calibrators and/or control materials must be assured through available reference measurement procedures and/or available reference materials of a higher order". Thus a worldwide reference system needs to be established by collaboration and mutual recognition between the United States National Institute of Standards and Technology (NIST), European Metrology Institutes (EUROMET), regulatory bodies (e.g. United States Food and Drug Administration, FDA) the IVD industry and professional organizations (e.g. International Federation of Clinical Chemistry and Laboratory Medicine, IFCC). In June 2002, in Paris, representatives of international and regional organizations and institutions decided to form the "Joint Committee on Traceability for Laboratory Medicine" (JCTLM), which will support industry in registration and licensing of the "CE" label to test systems conforming to the IVD Directive.Presented at the International ILAC/IAF Conference on Accreditation in Global Trade, 23–25 September 2002, Berlin, Germany     

Getting the most from your laboratory information system in the hematology laboratory

As laboratories continue to downsize, commercialize and become more businesslike in today’s managed care environment, their present and future success will greatly depend on the efficiency and flexibility of their laboratory information system (LIS). Today, LIS is a primary tool for managing business and communication. Laboratories that hope to remain competitive in today’s dynamic health care must continue to implement new and innovative approaches with their LISs. Received: 26 July 2002 Accepted: 6 August 2002 Presented at the European Conference on Quality in the Spotlight in Medical Laboratories, 7–9 October 2001, Antwerp, Belgium