Automatic Determination of Zeta Potential Isoelectric Point

Testa Analytical Solutions e.K reports on how automation of isoelectric point measurement can be achieved using a BI-ZTU autotitrator in combination with a Nanobrook zeta potential analyzer.

The stability of a dispersion is commonly determined by zeta potential. However, the surface chemistry of solid particles in a dispersion can be modified by altering parameters such as pH, surfactant concentration and salt concentrations. Hence, it is important to determine how pH affects the zeta potential of a dispersion. By studying the isoelectric point, scientists can determine how pH affects zeta potential and therefore can determine at which pH the zeta potential is zero.

The BI-ZTU autotitrator option for NanoBrook zeta potential analyzers is ideal for automatic determination of the isoelectric point of colloids, for the detection of the onset of aggregation as a function of pH and for measure effect of salt concentration (ionic strength) on zeta potential. Incorporating four pumps the BI-ZTU autotitrator provides unparalleled flexibility for optimising reagent use. Using a BI-ZTU autotitrator enables automatic addition of acid or base to adjust the pH of your sample, recording of pH, and loading of sample into the electrode cell of a Nanobrook zeta potential analyzer.  Using this set-up allows you to determine zeta potential at a particular pH and then automatically repeat the measurement for the next pH in the series.

By minimising manual labour requirements using the BI-ZTU in combination with the Nanobrook zeta potential analyzer the cost of isoelectric point determination is drastically reduced.

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