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Zeta potential analyser
Keywords Brookhaven Instruments, Analysis, Coatings, Pharmaceutical
The ZetaPALS zeta potential analyser from Brookhaven Instruments (Plate 5) is reported to be an ideal instrument for use in primary research and development by both the pharmaceutical and coatings industries. Using phase analysis light scattering (PALS) to accurately measure small particle velocities, this analyser claims to be over one thousand times as sensitive as conventional electrophoresis techniques.
Plate 5 ZetaPALS
According to Brookhaven, ZetaPALS can determine zeta potential in virtually any liquid, whether polar or non-polar, aqueous or organic, viscous or free-flowing. It reportedly also works in solutions of high ionic strength and under conditions of very low zeta potential, such as near the isoelectric point.
All this is said to be achieved without the need for the very high voltages demanded by other techniques. Specific applications include analyses of the non-aqueous dispersions used in metered dose inhalers and the pigments used in non-polar materials such as paints.
ZetaPALS also has an optional facility for sub-micron particle size distribution analysis using dynamic light scattering. With this, the ZetaPALS can give complete characterisation of colloidal systems for monitoring and controlling factors like dispersion, flocculation and stability. Clear, easy-to-use Windows software allows single or automatically-repeated measurements, while zeta potential can be plotted against user-defined parameters such as pH or additive concentration.