Zeta Potential Analysis

Features at a glance

• Accurate, rapid, easy to use
• One piece, easy-fill disposable sample cells
• No cell alignment or calibration
• Temperature control, -5 °C to 110 °C
• Customizable reports, SPC charts,
  two-parameter plots, graphical overlays
• Can resolve multi-modals
• Upgradable with PALS for 1,000x sensitivity
• Built in automatic procedures and parameters
• Integrated computer
• Upgradeable to include full particle sizing functionality

Reliable, Accurate, Easy to Use

The Brookhaven ZetaPlus is the simplest and most accurate particle electrophoresis system available. This revolutionary instrument has been designed to eliminate the shortcomings inherent in other zeta potential instruments. The ZetaPlus software is simple and intuitive to operate but yet offers flexibility and a full range of means for those who wish to tune their experiments to specific circumstances.

The screen image shown below indicates the clear and concise presentation. Information obtained from the sample is updated in real time and the user can select from several display formats. A Literature of physical constants for many usual suspending fluids is provided but the user may provide his/her values if desired. Printed reports are fully customizable and are provided in color with the supplied printer.

Comprehensive Information

The ZetaPlus measures complete electrophoretic mobility distributions in seconds including mutimodals (an example of a bimodal zeta potential sample can be seen on the results screen from analyzing a created mixture of charged particles.)

In the example below the results of analyzing a mixture of alpha and gamma Aluminas in 1 mMolar KCl at pH10 is displayed. The left peak is identified wth the green cursor and shown to have a zeta potential of -20.54 mV. If the other peak is chosen the value given is -5.00 mV. The ability of the Brookhaven ZetaPlus to provide this information distinguishes it from other methods which provide only an ensemble average.

Derive Extended Information

The user can tabulate or graph any appropriate pair of parameters allowing, for example, the determination of the iso-electric point (IEP) as in the example below. The ZetaPlus is provided with a pH meter which can be used to measure this value. If the system has the available particle sizing option installed the user can also obtain data for a complete electrophoretic fingerprint (ref: Prescott, Rowell & Bassett, Langmuir V13, pp1978-1986, 1997)

Statistical Process Control

SPC software is standard of course and the user may employ this and other included comparison techniques (graphical overlays) to obtain information about multiple samples.

Unique Cell Design

The unique cell configuration eliminates the electroosmotic effect: hence no stationary levels, no alignment and no calibration are required, as evidenced by the excellent agreement with NIST1980, a standard reference material. The ZetaPlus uses low cost, disposable sample cells. There is no assembly or maintenance required: cross contamination is eliminated. Glass and quartz cells are available optionally. The same basic cell design is used with the ZetaPALS.

Extreme Sensitivity and Particle Sizing options

For measurements of samples with very low mobility - in organic solvents, in oils, in viscous fluids, at very high salt concentrations, or very near the l.E.P. the Bl-PALS option will provide a 1,000x increase in sensitivity to the ZetaPlus. This Phase Analysis Light Scattering technique is available only from Brookhaven Instruments and it provides a truely outstanding increase in performance. The option to add the full functionality of our 90Plus particle size analyzer to either a ZetaPlus or a ZetaPALS instrument offers a multi function system which is unmatched for particle characterization.

Typical Applications

• Liposomes and biocolloids
• Ceramics and refractories
• Pigments and inks
• Pharmaceuticals
• Emulsions (foodstuffs, cosmetics)
• Wastewater treatment monitoring
• Latexes
• Carbon blacks

Specifications

Zeta Potential	Size range suitable for measurement	1 nm to 100 µ
	Mobility range	10-9 to 10-7 m2 /V*s
	Zeta potential range	-220 mV to 220 mV (*)
	Maximum sample concentration	10% v/v (*)
	Sample volume	180 µL, 600 µL, 1250 µL
	Maximum sample conductivity	7.5 mS/cm
	Signal processing	Electrophoretic Light Scattering, ELS (aka LDV)
Particle Size	Size range (radius)	< 0.3 nm to > 3 microns (*)
	Sample volume	10 µL, 40 µL, 1 - 3 mL
	Concentration range	0.1 mg/mL to 10% v/v (*)
Molecular Weight	Molecular weight range (estimated from hydrodynamic diameter)	1 KDa to 25 MDa
	Molecular weight range (calculated using Debye plot) requires BI-APD	1 KDa to 25 MDa
	Minimum sample volume	10 µL
General	Temperature control range	-5 °C to 110 °C, ± 0.2 °C
	Measurement angles	Three angles, two for particle sizing one for zeta potential
	Condensation control	Purge facility using dry air, nitrogen preferred
	Standard laser	35 mW red diode laser, nom 660 nm
	Correlator	TurboCorr, 25 ns min, 100% real-time, 100% eff.
System Compliance	CE certification	Class I laser product, EN 60825-1:2001, CDRH
System	Dimensions	23.3 cm x 42.7 cm x 48.1 cm (HWD)
	Weight	15 kg
	Power	100/115/220/240 VAC, 50/60 Hz, 150 W max
Notes:
(*) Sample type dependant

A policy of continual improvement may lead to specification changes.

Options and Accessories

Accessories	BI-ZTU, Autotitrator	4-pump, pH, temp, conductivity, additive
	BI-870, Dielectric constant meter	Improves accuracy for solvent mixtures for enhanced zeta potential determination
	Uzgiris cell	Standard, eliminates electro-osmosis completely
Options	Lasers	HeNe 632.8 nm, Freq. Doubled 532 nm
	BI-MAS	Required for particle size measurements
	BI-APD	Detector required for molecular weight measurements
	90PDP	Required for Debye plot measurements
	Narrow band filters	632.8 nm, 532 nm to block fluorescence
	Flow mode option	90PFC flow cell allows DLS size for GPC/SEC
	21 CFR part 11 software option	Software assists ERES compliance
	Research software option	BI-DLSW/BI-ISDAW allows more fitting algorithms