Simplify pH, conductivity and additive titrations on your Zetasizer Nano

A cost effective accessory designed to automate the measurement of size and zeta potential as a function of pH, conductivity or any soluble additive.

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The MPT-2 is an accessory for the Zetasizer Nano that provides extensive automation for a number of measurements that are routinely required when characterizing the size and zeta potential of dispersed particles and molecules.

Both the size and zeta potential can be measured in sequence as part of the automated titration.

pH is one of the main influences of the zeta potential of materials, so measuring zeta potential as a function of pH, and the determination of the isoelectric point are often required. Automating this improves productivity by proving a complete measurement using a stored method.

Conductivity is also measured, and automation can speed up the determination of whether ions in a formulation are specifically or non-specifically bound.

The same automation can be extended to study the effect of the concentration of additives such as surfactants and polyelectrolytes, and there is a dilution function to study the effect of dilution on the size and zeta potential of the sample.

  • Complete automation of pH, conductivity and additive titrations.
  • Simplify titrations by running a standard method.
  • Improve productivity through hands off operation.
  • Size and zeta potential measurement at each point (Zetasizer Nano ZSP and ZS only).
  • 3 syringe dispensing units for the titration of acids, bases, salts and other dissolved aqueous additives.
  • Software integrated with the Zetasizer Nano.
  • Color coding of titrants in software and hardware simplifies operation.
  • Magnetic stirrer to ensure complete mixing.
  • Use with a titrant autodegasser unit (DEG0003) is recommended to give evenly spaced pH points.

How it works

The MPT-2 incorporates a pump to recycle the sample from the reaction vessel to the Zetasizer, a pH probe and measurement electronics, and 3 syringes for 3 titrants.

These are low volume displacement syringes, with well characterized plunger diameters. This gives the ability to accurately add very small amounts of titrant, as low as 0.28µL, which enable the precise targeting of the desired value. This is particularly important at pH values close to 7.

If very wide pH range titrations are required, it is possible to use two concentrations of acid for example. The titrator will automatically use the appropriate titrant to provide the minimum amount of additive with the maximum accuracy.

The software and hardware are color coded to match the titrator setup in the software with colored lights next to the titration containers and appropriate colored connectors on the tubing.

When a new method is set up, the software assesses the volume of titrants required to perform the complete sequence, and will give a warning if the reaction vessel is likely to overflow. This indicates that a more concentrated titrant is required to reach the extremes of the range requested.

The whole measurement sequence can be stored for subsequent reuse, and functions such as ‘Go to pH’ are available to construct customized titration sequences, that can include changes of conductivity and pH in a single method.


System compatibility Size and zeta potential titration: Zetasizer Nano ZSP, ZS, ZS90. Size titration: Zetasizer Nano S, S90. Zeta potential titration: Zetasizer Nano Z.
Solvent compatibility Aqueous samples.
Minimum sample volume 5mL.
Includes MPT-2 autotitrator, liquid filled micro pH probe kit, disposable sample cups, magnetic stirrer.