Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 4 November 1994:
Vol. 266. no. 5186, pp. 773 - 776
DOI: 10.1126/science.266.5186.773
Prev | Table of Contents | Next

Articles

Use of Taylor-Aris Dispersion for Measurement of a Solute Diffusion Coefficient in Thin Capillaries

Michael S. Bello 1, Roberta Rezzonico 2, and Pier Giorgio Righetti 2

1 Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Bolshoi 31, 199004, Russia
2 Faculty of Pharmacy and Department of Biomedical Sciences and Technologies, University of Milan, Via G. Celoria 2, Milan, 20133, Italy

A method for the fast measurement of the diffusion coefficients of both small and large molecules in thin capillaries is reported. The method relies on Taylor-Aris dispersion theory and uses standard instrumentation for capillary zone electrophoresis. With this equipment, which consists of thin capillaries (50 to 100 micrometers in inner diameter), an injection system, detector ports, and computer data acquisition, a sample plug is pumped through the capillary at known velocity and the peak dispersion coefficient (D*) is measured. With the experimentally measured values of D* and flow velocity, and knowledge of the inner diameter of the capillary, the molecular diffusion coefficient (D) can be rapidly derived. For example, for ovalbumin a D value of 0.759 x 10-6 square centimeter per second is found versus a tabulated value of 0.776 x 10-6 square centimeter per second (error, 2 percent). For hemoglobin a D value of 0.676 x 10-6 square centimeter per second is obtained versus a literature value of 0.690 x 10-6 square centimeter per second (error, 1.5 percent).

Submitted on May 27, 1994
Accepted on September 15, 1994


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Microsecond electrophoresis.
M. L. Plenert and J. B. Shear (2003)
PNAS 100, 3853-3857
   Abstract »    Full Text »    PDF »
Capillary Electrophoresis Measurements of Electrophoretic Mobility for Colloidal Particles of Biological Interest.
J. R. Glynn Jr., B. M. Belongia, R. G. Arnold, K. L. Ogden, and J. C. Baygents (1998)
Appl. Envir. Microbiol. 64, 2572-2577
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)