32
LMS Issue 4 | 2014
Liquid Handling/Analysis
Count on it!
T
he new Eppendorf Multipette®
M4 is simple, stress-free and ergonomic. It reaches beyond traditional
pipette limitations. Even liquids that
are difficult to pipette are no match
for the M4. The Multipette M4 makes
performing long pipetting series faster
and easier. The aspirated liquid can
be dispensed up to 100 times without
refilling the tip and it has a volume
selection range of 1μl to 10ml.
On the Multipette/Combitip system,
volumes are dispensed using the positive displacement principle. The liquid
is directly dispensed without an air
cushion, ensuring the correct volume
is always dispensed regardless of the
density, viscosity and volatility of the
liquid. In addition to serial dispensing, the Multipette is also the perfect
instrument that is able to go beyond
the limitations of a standard pipette.
The instrument produces stressfree work via an integrated step
counter. Dispensing procedures can
be continued error-free after an interruption or distraction. The clearly
arranged and easy-to-read display
guarantees intuitive operation. The
step counter supports error-free
filling. The integrated ‘sleep’ function
switches off when the M4 is not being
used, thus reducing energy consumption and saving battery life. The central
Combitip ejector ensures full emptying
that can easily be ejected with one hand
using the operating lever. ⚛
Merck Millipore
Field Marketing Manager: Adele Heath
Tel: 011-372-5129
Email: [email protected]
Guidelines for Good Density Measurement
Helpful tips for accurate densit y
results with DMA M density meters
Follow five guidelines for accurate
and reproducible density results:
Water check: Perform a water
check every day before measurements. Only use ultra-pure (for example,
bi-distilled or de-ionised) water.
Adjustment: An adjustment
changes the instrument constants. For the consistency and comparability of results, an adjustment should
only be performed if the water check
fails and using fresh water and cleaning
1
2
the measuring cell does not help.
Sample preparation: To get
reproducible results prepare
samples with care, and the same way
every time.
Sample filling: Fill the measuring cell very carefully and
without bubbles. Use automatic sample
filling devices to eliminate filling errors
due to the operator.
Cleaning: Remove the sample
from the measuring cell immediately after the measurement and clean
the instrument regularly.
3
4
5
All in all, what makes for good density measurement? Awareness of the entire
measurement workflow, from start to finish – from the moment one starts
working in the lab to the moment they are cleaning the equipment. Just
keep a trained eye on the five basic areas and you will be well on your way. ⚛
Anton Paar Southern Africa (Pty) Ltd
Contact: Andre van Zyl
Tel: 011-021-5165/6/7
Email: [email protected]
It’s all in the LiquiPhysics
M
ettler Toledo’s LiquiPhysics™
density meters provide accurate
results for quality control checks in
liquid analysis applications. Their range
of digital benchtop and portable density
meters measure density and specific
gravity with high precision and a short
measuring time. The benchtop density
instruments have a built-in Peltier
thermostat to control the temperature.
These meters have a rugged design and
ErgoSense™ for touch-free operation.
The portable density meters provide
automatic temperature compensation
for Brix%, alcohol, Plato, API and %
sulphuric acid or user-defined temperature correction coefficients to suit
specific samples.
LiquiPhysics meters can be upgraded
with a refractometer, pH meter, titrator,
spectrophotometer or polarimeter into
a multi-parameter system. Density,
refractive index and pH of raw material
and products are important parameters
that need to be accurately determined.
Often, the colour or the optical rotation of the samples also needs to be
measured.
LabX™ software for LiquiPhysics
Excel lence Systems convenient ly
manages measurement results, offers
full support to comply with the 21
CFR 11 regulations, enables smooth
and seamless LIMS/SAP integration,
and organises comprehensive sample
lists. No computer is required. LabX,
connected via ethernet, utilises the
instrument’s terminal so an operator
can continue