Expanding the Possibilities of Zeta Potential with PALS Technique

Eric Farrell, International Sales Engineer , Brookhaven, Holtsville, New York, 11742 USA

Characterizing the zeta potential of delicate proteins, biological samples, particles in high salt, and even the charge on macroscopic surfaces has always proven a difficult task.  Delicate proteins and biological samples are easily degraded when a significant voltage is applied.  Furthermore, the low dielectric constant of organic solvents does not easily permit the transmission of an electrical field through the liquid.  The presence of high salt (>~150mM ionic strength) in a sample may also yield to rapid sample degradation during zeta potential analysis.

In order to successfully measure difficult samples such as these, a highly sensitive technique that is capable of detecting the slightest movement of particles with the application of a minimal electrical field must be utilized.  Successful analysis of such difficult samples are presented with the use of Brookhaven Instrument’s true Phase Analysis Light Scattering (PALS) technique.