Clinical Chemistry Link to Randox Laboratories Web Site
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 28: 1931-1935, 1982;
This Article
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Apple, F. S.
Right arrow Articles by Ladenson, J. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Apple, F. S.
Right arrow Articles by Ladenson, J. H.

Clinical Chemistry, Vol 28, 1931-1935, Copyright © 1982 by American Association for Clinical Chemistry

Relationship between direct-potentiometric and flame-photometric measurement of sodium in blood

FS Apple, DD Koch, S Graves and JH Ladenson

The relationship between direct-potentiometric and flame-photometric measurements of sodium has been studied in human sera and other, simpler systems. When water content was varied by using an inert substance (silica), de-ionized sera, or de-ionized individual proteins, the percentage that the flame photometric values were of the direct potentiometric Na+ values was identical to the measured water content. However, in 35 patients the percentage of Na+ values was 99.1% and the water content was 92.0%, a discrepancy of 7.1%. De-ionization of sera removed this discrepancy, apparently because of the lower pH of the de- ionized sera. The percentage of flame-photometric to direct- potentiometric Na+ values varied as a function of pH in pooled sera; in lyophilized and reconstituted sera; and in de-ionized, lyophilized, and reconstituted sera. Four explanations for the discrepancy between the percentage of Na+ values and the water content are discussed: a calibration problem, a measurement artifact, Na+ binding, and water binding. At this time there are no definitive data concerning which explanation is correct. We expect that our finding of a pH dependency for the percentage of measured Na+ values can be used to develop model systems to elucidate the mechanism producing the discrepancy between the percentage of Na+ values and the water content.


The following articles in journals at HighWire Press have cited this article:


Home page
 J. Clin. Pathol.Home page
P J Twomey, J Cordle, D R Pledger, and Y Miao
An unusual case of hyponatraemia in diabetic ketoacidosis
J. Clin. Pathol., November 1, 2005; 58(11): 1219 - 1220.
[Abstract] [Full Text] [PDF]

Home page
 NEJMHome page
A. I. Arieff, J. C. Ayus, A. J. Martin, D. E. Bruns, J. H. Ladenson, M. G. Scott, A. S. Kashyap, S. Kashyap, C. van Heyningen, G. V. Gill, et al.
Hyponatremia
N. Engl. J. Med., September 21, 2000; 343(12): 886 - 888.
[Full Text]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1982 by the American Association for Clinical Chemistry.