Since this article was written the author has died.
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Widmer, M. 2006. Gravimetry. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
Gravimetry is one of the oldest techniques of quantitative analysis. In gravimetry, the analyte is precipitated as a stoichiometrically defined compound. After collecting and drying, the precipitate is weighed on an analytical balance and the analyte is determined from the mass and the known stoichiometry of the analytes in the precipitated compound. Although many instrumental methods have superseded gravimetry it is a very important method for standardization processes. Since calibration is inherent in the relative molecular masses and the stoichiometry of the chemical reaction, it represents one of the few primary methods.
As a closely related method, electrogravimetry is also considered. In electrogravimetry the analyte is deposited on a metal, for example a platinum electrode, by electrolysis with a controlled current and its mass is evaluated from the weight difference of the electrode before and after electrolysis. Electroseparation of two analytes is feasible by judicious choice of the electrode potential.