Zetasizer Nano ZS

Overview

The Zetasizer Nano ZS is the top of the Zetasizer range and is particularly suitable where there are a wide range of applications and the highest performance is required.

It incorporates a two angle particle size analyzer for the enhanced detection of aggregates, measurement of small or dilute samples, and samples at very low or high concentration, a zeta potential analyzer, plus a molecular size and molecular weight analyzer. The system can be connected to a GPC / SEC system to use as a chromatography detector.

• Size measurement from 0.3nm (diameter) to 10 microns using patented NIBS (Non-Invasive Back Scatter) technology.
• Zeta potential of proteins and particles using patented M3-PALS technology.
• Molecular weight measurement down to 980Da.
• Sample concentrations from 0.1ppm to 40%w/v.
• Protein size measurement as dilute as 0.1mg/mL (Lysozyme).
• A ‘Quality Factor’ to give confidence in the data.
• An ‘Expert advice’ system to help to improve sample preparation or optimize the measurement.
• 21CFR part 11 software option to enable compliance with ER/ES.
• Research software option to give access to further features and analysis algorithms for the light scattering specialist.
• Automation of measurements using an autotitrator option.
• Flow mode capability to enable use as a GPC / SEC detector.
• Alternative laser, 50mW at 532nm for samples incompatible with the standard 633nm laser.
• Optical filter option to improve measurements with fluorescent sample.
• Temperature range extension option to 120°C.

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How it works

The Zetasizer Nano ZS incorporates three techniques in a single compact unit, and has a range of options and accessories to optimize and simplify the measurement of different sample types.

Dynamic Light Scattering is used to measure particle and molecule size. This technique measures the diffusion of particles moving under Brownian motion, and converts this to size and a size distribution using the Stokes-Einstein relationship. Non-Invasive Back Scatter technology (NIBS) is incorporated to give the highest sensitivity simultaneously with the highest size and concentration range.

Laser Doppler Micro-electrophoresis is used to measure zeta potential. An electric field is applied to a solution of molecules or a dispersion of particles, which then move with a velocity related to their zeta potential. This velocity is measured using a patented laser interferometric technique called M3-PALS (Phase analysis Light Scattering). This enables the calculation of electrophoretic mobility, and from this the zeta potential for the accurate measurement of a wide range of sample types and dispersion media including high salt concentrations and non-aqueous dispersants.

Static Light Scattering is used to determine the molecular weight of proteins and polymers. In this technique, the scattering intensity of a number of concentrations of the sample is measured, and used to construct a Debye plot. From this the average molecular weight and second virial coefficient can be calculated, which gives a measure of protein solubility.
This technique is very demanding on the sensitivity and stability of the whole system, and requires that every element of the design is optimized to ensure accuracy and repeatability.

Software
The software is designed to be versatile and rich in features without compromising ease of use. Standard Operating Procedures (SOP) simplify routine measurements, a quality factor gives a single place for confirmation of data quality, and an expert advice system is provided to assist with data interpretation.

Options
The MPT-2 Autotitrator enables the study of the effect of changes in pH, conductivity, or any additive to be automated.
A range of disposable and reusable cells are available to optimize the measurement in terms of sample volume, concentration and flow measurement.

Other options include filters to improve the measurement of fluorescent samples, a temperature range extension to 120ºC and a Viscometer to determine the sample viscosity to the accuracy required for the techniques used.

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Specification

Particle size and molecular size

Parameter

Specification

Measurement range:

0.3nm – 10.0 microns* (diameter)

Measurement principle:

Dynamic Light Scattering

Minimum sample volume:

12µL

Accuracy:

Better than +/-2% on NIST traceable latex standards

Precision/Repeatability

Better than +/-2% on NIST traceable latex standards

Zeta potential

Parameter

Specification

Measurement range:

3.8nm – 100 microns*

Measurement principle:

Electrophoretic Light Scattering

Minimum sample volume:

150µL

Accuracy:

0.12µm.cm/V.s for aqueous systems using
NIST SRM1980 standard reference material

Molecular weight

Parameter

Specification

Measurement range:

980Da – 20M Da*

Measurement principle:

Static Light Scattering using Debye plot

Minimum sample volume:

12µL (3-5 sample concentrations required)

Accuracy:

+/- 10% typical

Patents granted:

NIBS
EP 0 884 580, DE 19725211, US 6016195, JP 2911877
M3, Mixed mode measurement
UK 2361772, EP1154266, US7217350, JP2002005888

Temperature control range:

0ºC - 90ºC +/-0.1**, 120ºC option

Light Source:

He-Ne laser 633nm, Max 5mW

Laser safety:

Class 1

Power: (V, Hz, VA)

100VA

Weight and dimensions:

Parameter

Specification

Dimensions (W, D, H)

320mm, 600mm, 260mm (W,D,H)

Weight: (kg)

21

Operating environment:

Parameter

Specification

Temperature:

15°C – 40°C

Humidity:

35% - 80% non-condensing

Software:

Parameter

Specification

Operating platforms:

Windows XP, VISTA, Windows 7
(compatible only with 32 bit versions of
Windows XP Pro and Windows 7)

*maximum range, sample dependent

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Accessories

A range of accessories are available to make life easier, or to add capability to the system

MPT-2 Autotitrator

Automates experiments to study the effect of a change in sample conditions such as pH, conductivity, or the concentration of an additive. Up to three titrants can be used to increase and decrease pH for example.

See the MPT-2 Autotitrator

SV-10 viscometer

An extremely simple and fast method of measuring the viscosity required for molecular size and zeta potential measurements. In 15 seconds the viscosity of 10mL of sample or dispersant can determined to an accuracy of 1% of samples with as low a viscosity as water. Water jacket supplied for temperature control (Note: Water bath required and available at additional cost)

See the SV-10 viscometer

Factory fitted options

50mW 532nm DPSS laser

For use where the sample is incompatible with the standard 633nm laser, either because the sample absorbs or fluoresces, or the sample is photosensitive.

The addition of this option does not affect the system specifications

Narrow band filters

Useful where the sample fluoresces. Will select the scattering from non-fluorescing particles and improve the signal to background ratio

High temperature capability

Increases the high temperature capability from 90ºC to 120ºC. Suitable for samples in wax media that melt above 90ºC

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