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A system of terms applicable to ordered microporous and mesoporous materials is proposed, and rules for writing a standardized crystal chemical formula for such materials are presented. The recommendations are based both on common usage and on a systematic classification scheme. The nomenclature has been developed to encompass all inorganic materials with ordered, accessible pores with free diameters of less than 50 nm. The crystal chemical formula describes the chemical composition of both the guest species and the host, the structure of the host, the structure of the pore system, and the symmetry of the material. This formula can be simplified or expanded to suit the user’s requirements.
Pure Appl. Chem., Vol. 73, No. 2, pp. 381–394, 2001.
IUPAC Recommendations 2001
© 2001 IUPAC
IUPAC permission is acknowledged
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The correct use of the term “selectivity” and its clear distinction from the term “specificity” are discussed. A definition of selectivity is given, and it is recommended that the use of this term be promoted and that the use of the term “specificity” be discouraged.
Pure Appl. Chem., Vol. 73, No. 8, pp. 1381–1386, 2001.
IUPAC Recommendations 2001
© 2001 IUPAC
IUPAC permission is acknowledged
Abstract
The equipment known as the breath alcohol analyzer allows the determination of the amount of alcohol in the blood, ingested in the form of ethanol in alcoholic beverages, through the breath of a person. This determination is based on the principle that the alcohol contained in the blood is in equilibrium with the alcohol in the air in the lungs. The proposed experiment describes a procedure for determining the amount of alcohol present in a sample of alcohol vapor, simulating the conditions of a breath alcohol analyzer. The main objectives are:
- Discuss, in general, the principles used in a chemical breath alcohol analyzer.
- Introduce spectrophotometric methods of analysis and illustrate thier application.
- Introduce the use of the linear regression method to fit experimental data and demonstrate its use in obtaining the equation of an analytical calibration curve.
- Determine the amount of ethanol in the vapor of a alcohol sample, simulating the conditions of a breath alcohol analyzer used for determining the alcohol vapor based on the oxidation of alcohol by dichromate ions.
Keywords
breath alcohol analyzer, alcohol, ethanol, spectrophotometer, determination of ethanol, chemical analysis, linear regression, calibration curve
Autores
João Carlos de Andrade
Aline Renée Coscione
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!”
