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The relatively young field of ion mobility spectrometry has now advanced to the stage where the need to reliably exchange the spectroscopic data obtained worldwide by this technique has become extremely urgent. To assist in the validation of the various new spectrometer designs and to assist in inter-comparisons between different laboratories reference data collections are being established for which an internationally recognized electronic data exchange format is essential.
To make the data exchange between users and system administration possible, it is important to define a file format specially made for the requirements of ion mobility spectrometry. The format should be computer readable and flexible enough for extensive comments to be included. In this document, we define a data exchange format, agreed on by a working group of the International Society for Ion Mobility Spectrometry at Hilton Head Island, USA (1998) and Buxton, UK (1999).
This definition of this format is based on the IUPAC JCAMP-DX protocols, which were developed for the exchange of infrared spectra [1] and extended to chemical structures [2], nuclear magnetic resonance data [3], and mass spectra [4].
This standard of the Joint Committee on Atomic and Molecular Physical Data is of a flexible design. The International Union of Pure and Applied Chemistry have taken over the support and development of these standards and recently brought out an extension to cover year 2000 compatible date strings and good laboratory practice [5]. The aim of this paper is to adapt JCAMP-DX to the special requirements of ion mobility spectra [6].
Pure & Appl. Chem., Vol. 73, No. 11, p. 1765–1782, 2001
IUPAC Recommendations
© 2001 IUPAC
IUPAC permission is acknowledged
Abstract
Among the mathematical models used to represent the electronic structure of microscopic systems one of the most valuable is the Hartree-Fock model. The major problem to be solved in this model is the choice of the mathematical functions to be used to represent the Hartree-Fock orbitals. One of the most important suggestions for the Hartree-Fock method was formalized by J.J. Roothaan by way of the technique that was popularized as the method of linear combination of atomic orbitals or base functions. In other words, atomic and molecular orbitals can be obtained as linear combinations of base functions. Although the Hartree-Fock-Roothaan model has become computationally attractive, it is necessary to impose the solution of some technical issues such as:
- which mathematical functions could be used as the base sets? and
- how the base functions should be used to adequately represent the system under study?
The issues related to the alternatives used to answer these two questions will be detailed below.
Keywords
base functions, hydrogenoid base functions, Slater functions, Gaussian functions, Hellmann-Feynman theorem
Authors
Nelson Henrique Morgon
Rogério Custódio
Universidade Estadual de Campinas, Instituto de Química
Translated by
João C. de Andrade
Revised by
Carol H. Collins
Abstract
Volumetric methods using oxidation and reduction reactions depend on the potential of half-reactions involved but, beyond favorable potential conditions, the oxidizing and reducing agents must be stable in solution and the substance to be determined should have a stable oxidation state, defined before the titration is started. Iodometry is an indirect volumetric method, where an excess of iodide ions are added to a solution containing the oxidizing agent, which react producing an equivalent quantity of iodine that is then titrated with a standardized solution of sodium thiosulfate.
Keywords
half-reactions, oxidation state, volumetry, redox reactions, oxidizing agents, reducing agents, iodometry
Author
João Carlos de Andrade
Universidade Estadual de Campinas, Instituto de Química
Translated by
João C. de Andrade
Revised by
Carol H. Collins
Warning
Attention: “Read carefully the procedure before starting the experiment. Do not perform the experiment without being monitored by your teacher. In doubt ask for help!”
Abstract
This text aims to show that conductivity is not a phenomenon exclusively electrical or electronic. Other charged particles, ions, can generate conduction when moving in a solid reticulum, obeying very specific structural conditions.
Keywords
electrolytes, ionic crystals, crystalline reticulum, conductors, semiconductors, insulators
Author
Heloise de Oliveira Pastore
Universidade Estadual de Campinas, Instituto de Química
Translated by
João C. de Andrade
Revised by
Carol C. Collins
