Level is not a synonym of concentration

Clinica Chimica Acfa, 203 (1991) 417,418 0 1991 Elsevier Science Publishers B.V. All rights reserved OOO9-8981/91/$03.50

417

CCA 05189

Letter to the Editor

Level is not a synonym of concentration Dear Editor, The International Union of Pure and Applied Chemistry (IUPAC) and the International Federation of Clinical Chemistry (IFCC) define in a joint document several kinds of quantities related to the concentration concept [l]: catalytic (activity) concentration, mass concentration, number (of entities) concentration and substance concentration. Grouping the definitions of these concentration types, a resulting common definition may be the amount of a component divided by the volume of the system which the component belongs to. In this document the term level is not defined indeed it is not even mentioned. In the 67th edition of the CRC Handbook of Chemistry and Physics [2] the term concentration is defined as the amount of a substance in weight, moles, or equivalents contained in unit volume; the term level is not considered to be a synonym of concentration. Among the meanings of the word level found in the Webster’s Third New International Dictionary [3] or in the Oxford Dictionary of Current English [4], none of them corresponds to the physical-chemical concept of concentration. Why do many authors (more than one-half is my feeling) write level instead of concentration? Psycho-sociological reasons should exist to explain this phenomenon but I do not known them. (The same phenomenon occurs in Spain when the scientific community write in Spanish, perhaps due to the influence of the English language?). Notwithstanding, whatever the reasons, I think that the phenomenon should be corrected. Thus, I beg all the readers of this journal not to use the term level as a synonym of concentration when writing a scientific paper and, I beg the editors of scientific journals to substitute appropriately the term level by concentration in manuscripts approved for publication. X. Fuentes-Arderiu Servei de Bioquimica Clinica Hospital Princeps d’Espanya L’Hospitalet de Llobregat Barcelona, Spain

References 1 International Union of Pure and Applied Chemistry and International Federation of Clinical Chemistry. Approved recommendation (1978). Quantities and units in clinical chemistry. Clin Chim Acta 1979;%:157F-1833.

418

2 Weast

RC, Astle MJ. Beyer WH,

Eds. CRC

Handbook

of Chemistry

and Physics. Boca Raton: CRC

Press, 1986. 3 Babcock

Gove

Unabridged. 4 Allen

P, Ed.

Springfield:

Webster’s

RE, Ed., The Oxford

Correspondence 08907 L’Hospitalet

Third

New

Merrian-Webster, Dictionary

to: X. Fuentes-Arderiu, de Llobregat,

International

Dictionary

of the

English

Language

1986.

of Current

Selvei

Barcelona,

English. Oxford:

de Bioquimica

Spain.

Oxford

Clinica,

University

Hospital

Press, 1984.

Princeps

d’Espanya