Topics Covered
Introduction
to PIONA Gas Chromatography
Temperature
programming of PIONA Gas Chromatograph
Results
and Discussion of Application
Conclusion
About Bruker CAM
Introduction
to PIONA Gas Chromatography
Gas chromatography is a widely-used
method of chemical
analysis that analyses the chemical make-up of a substance that has
been
vaporised. The moving phase in a gas chromatographer (an inert gas)
carries the
vapour desired through a tube lined with a stationary phase. The main
physical
components of a gas chromatographer are the auto samplers, inlets and
detectors.
Gas chromatography is used in a large
range of industries,
including the engine fuels industry, for the characterisation of
hydrocarbons.
POINA gas chromatography is
specifically used for
characterising Paraffins, Iso-paraffins, Olefins Naphthenes and
Aromatics in
gasoline-range materials. It is currently the favoured technique to
characterise
petroleum streams by hydrocarbon group type. It does this using a
‘multidimensional’
approach, which allows the recognition of different hydrocarbon groups.
‘Multidimensional’ gas chromatography
analysis is now very
common in refinery laboratories across the globe. Although many
improvements
have been made since it was first introduced, there are still
improvements that
can be made.
One improvement that can be
implemented is a decrease in the
time it takes to analyse samples. This is an extremely useful
improvement which
would be of benefit to many industries, including the fuel industry.
Temperature
programming of PIONA Gas Chromatograph
Faster PIONA analysis is thought to
be achievable by using concurrent
heating.
The new Bruker
PIONA+™ Analyser has made great strides in this respect. This machine was developed
to provide
flexibility in determining the composition of spark ignition fuels by
hydrocarbon
group-type through the use of multi-dimensional gas chromatography.
The Bruker
PIONA+™ Analyser has various ‘traps’ that help to group
various hydrocarbons
by carbon numbers.
Temperature programming of the Bruker
Molsieve 5A trap so
that is it ‘concurrent’ with the Bruker
Molsieve 13X trap
results in several large advantages.
Firstly, the application range for
wide samples is greatly
increased. Also, Quantification of volatile hydrocarbons in wide range
samples
is improved.
Importantly, the application range
analysis time is reduced
significantly.
Below is a review of an application
to demonstrate how these
advantages are achieved.
Results
and Discussion of Application
The Instrumentation used in this
application was: Bruker
PIONA+ Analyzer,
Software, CompassCDS, and Chromatography Software from Bruker with
PIONA+
plug-in software.
In this application, the PIONA+
system was set up to
separate normal and iso-paraffins, naphthenes and aromatics (PINA). In
conventional mode, there can be breakthrough of volatile n-paraffins
from the Bruker
Molsieve 5A trap,
which can make quantification quite difficult. Also, co-elution is
possible for
high C number isoparaffins and corresponding naphthenes. In addition,
the total
analysis time is approximately two hours.
Figures 1 shows some of the
quantification problems encountered
using conventional PINA analysis. A calibration mix was analyzed and
breakthrough is apparent. The separation per component group and per
carbon
number is clearly shown. However, breakthrough of the
volatilen-paraffins
challenges the software, for example, in the case of nP5 from 7 to 9.5
minutes
as shown in Figure 1b. This effect is particularly evident around 9
minutes
when the N6 (napthenes C6) elutes.
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Figure 2 clearly shows the improved
performance of the fast
PINA system, enabling easier quantification and reduced analysis time.
In the regular
PINA mode analysis time is about 95 minutes. In fast PINA mode, this is
reduced
to 55 minutes.It is also apparent that the analysis time reduction is
achieved without
adaptations in hardware and without any negative effect on
chromatographic separation.
This means that the chromatographic specifications remain unchanged.
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Conclusion
It is shown in this test that
concurrent temperature
programming of the Molsieve
5A trap together with the Molsieve
13X trap in the Bruker
PIONA+ Analyzer
greatly extends the application range for wide samples. Quantification
of
volatile hydrocarbons in wide range samples is also improved. The
reduction of
analysis time in this example was 40 minutes, or nearly 45 %.
About
Bruker CAM
Bruker is the new name in chemical
analysis. Accurate and
comprehensive analysis of exogenous and discrete elements in a wide
range of
sample matrices are key applications for many analytical chemistry
groups. To
address the needs and challenges of analysts working in those areas,
Bruker has
expanded their product family to provide, and expertly support, a
series of
fully integrated solutions including:
· Gas Chromatography-Mass
Spectrometers (GC/MS and GC/MS/MS)
· Inductively Coupled Plasma Mass
Spectrometers (ICP-MS)
· Gas Chromatography Systems (GC)
Widely used in food and consumer
safety testing, forensic,
industrial, environmental, and clinical laboratories, these systems are
well
accepted and established market leaders that universally deliver
outstanding performance
at a premium value.
This information has been sourced,
reviewed and adapted from
materials provided by Bruker
CAM.
For more information on this source,
please visit Bruker
CAM.