CRITICAL PRESSURE = 7.3 MPA
Nexera UC Prep - Stacked Frac tion System
Rewriting the Book on
Supercritical Fluid
Chromatography
Fluids become supercritical when they
are highly compressed and take on the
properties of both a liquid and a gas.
Supercritical carbon dioxide (CO2)can
be
O
used as the mobile phase in supercritical
fluid chromatography (SFC).
Until recently, this technique had been
overlooked in favor of high-performance
liquid chromatography (HPLC) and
gas chromatography (GC). However,
new developments in the field have
demonstrated that SFC can be a highly
cost-effective, accurate and sensitive
solution capable of outperforming
HPLC and GC. In light of these new
technologies, it’s time to reshape the
field of chromatography with SFC.
Back to basics: SFC
and supercritical C
O2
A supercritical state occurs when a gas or liquid is subjected to
temperatures and pressures that exceed its critical point.
In this state, it will display properties of both liquids and gases, the
advantages of which can be applied to SFC:
Diffusivity comparable
Increased density
Dynamic viscosity
to a gas
comparable to a liquid
comparable to a gas
Rapid carrying
High flow rate
Improved
and eluting
and variable
solvent
for an efficien
solvation
capabilities
mobile phase
strength
Using supercritical fluids for chromatography is not a novel idea. In fact, supercritical fluids have
been used as a mobile phase for separation for over 60 years, emerging originally under the name
“high-pressure gas chromatography”.
Cl
H
HPGC was initially performed using supercritical monochloro
C
difluoromethane
and dichlorofluoromethane, before carbon
H
dioxide (CO2) was discovered as a potential mobile phase
Cl
.1, 2
F
O2
C
F
O
C
O
Cl
F
Supercritical extraction and chromatography has been used
in industrial applications for decades, beginning with the
decaffeination of coffee in the 1970s.
3
Why CO2?
O
CO2 has several advantages over other supercritical fluids, making it
O2
the standard mobile phase for high-performance SFC.
CO2 Phase Diagram
O2
CRITICAL TEMPERATURE = 31°C
SOLID
SUBCRITICAL FLUID
SUPERCRITICAL FLUID
CRITICAL POINT
TEMPERATURE (°C)
Critical temperature and
pressure can be achieved
without environmental
extremes
Chemically inert
Non-toxic and
Inexpensive and
non-corrosive
abundant at
high purity
Advantages of C
O2
Reverts to a gas at
Miscible with most
room temperature and
co-solvents, allowing
atmospheric pressure,
C
dissolution of a wide
O2
resulting in high
range of both polar and
recovery rates and rapid
non-polar analytes
purification
Time to rethink
supercritical flui
chromatography
Over its lifetime, SFC has often been overshadowed by other
chromatography techniques. As a result, many first-time users of SFC
may have misconceptions about the modern face of this technique, but
it’s time to set the record straight.
Misconception
Fact
SFC can be used to separate both chiral and achiral molecules and is often used to
SFC is only useful
separate pharmaceutically active compounds such as vitamins, steroids and barbiturates.
for chiral molecules
Chiral
Achiral
SFC requires
The same principles of chromatography apply to both HPLC and SFC, meaning that
specialized
expertise is fully transferable. Additionally, the columns (e.g., silica and octadecyl) and
expertise and
detectors (e.g., photodiode array (PDA) and mass spectrometry) used in HPLC can be
equipment
directly transferred to SFC.
SFC is expensive
SFC systems have a higher benefit-to-cost ratio compared to HPLC, as the low viscosity
and time
and high diffusivity of supercritical CO2 allow for higher flow rates for faster analysis
O2
consuming
and separation, with no loss of sensitivity.
HPLC
Column:
Shim-pack HRC-Sil
(250 x 4.6 mm I.D.)
Mobile phase:
N-hexane/2-propanol
(99/1)
Flow rate:
1.0 mL/min
Temperature:
40°C
Detection:
UV 290 nm
SFC
Column:
Shim-pack UC-Sil
(250 x 4.6 mm I.D.)
Mobile phase:
CO2 /Methanol (95/5)
O2
Flow rate:
3.5 mL/min
Temperature:
40°C
Back-pressure:
10 MPa
Detection:
UV 290 nm
CO2-based SFC
Adding polar solvents allows SFC to separate polar substances (e.g. small peptides,
can only be used
polar pesticides, etc.). Furthermore, the supercritical properties of CO2 make it well
O2
for non-polar
suited to comprehensively analyze compounds over a wide polarity range not possible
compounds
with HPLC or GC alone.
Detection
Coupling SFC with a mass spectrometer (MS) can enable greater sensitivity in some
isn’t sensitive
circumstances than LC/MS. This is due to an alternative ionization mechanism
enough for many
caused by the interaction of CO2 with the solvent.
O2
applications
Suitable for a wide
range of applications
SFC is a well-established technique in the pharmaceutical industry. However, it is also suitable for a
wide variety of industries and applications:
•
Purification of drugs
PHARMACEUTICS
•
Analysis of drug formulations
•
Chiral separations
•
Pharmacokinetic studies
BIOANALYSIS
•
Forensic applications
•
Lipidomics
•
Contaminant analysis
FOOD SCIENCE
•
Quality control
•
Analysis of complex compounds,
e.g., lipids, pesticides
•
Bioactivity analysis in traditional
medicine
•
Quality control and contaminant
NATURAL PRODUCTS
analysis
•
Production of sustainable natural
products
End-to-end solutions
with Shimadzu
Shimadzu has created a comprehensive “Unified Chromatography” analytical scale system, in Nexera™
UC; but what is Unified Chromatography? UC characterizes the use of a very wide gradient, from a
CO2-rich supercritical/ sub-critical mobile phase (SFC) to a completely liquid mobile phase like in LC.
.1
O2
This is a versatile technique that allows separation of hydrophobic and hydrophilic compounds in a
single analysis. To meet current needs for a reliable preparative scale instrument, Shimadzu has worked
closely with the Enabling Technologies Consortium (ETC), a group of pharmaceutical and biotechnology
companies, and released the Nexera™ UC Prep. This system offers the high performance of the
Nexera UC with reliable high-performance semi-prep purification. Both systems also enable the on-line
extraction (SFE) and analysis (SFC) of a wide range of target samples for high-sensitivity detection and/
or purification
HIGHLY VERSATILE CHROMATOGRAPHY: NEXERA UC AND NEXERA UC PREP
Analytical scale UHPLC/SFC switching system
Fractionation/purification at both analytical
allows screening by UHPLC and SFC in same batch
and preparative scales with addition of a
fraction collector
94.2% reduction
Fully automated
High resolution even at high
in organic solvent
on-line extraction
flow rates
consumption
and separation
for improved
sustainability
Meeting every need:
Shim-pack UC columns
Due to the gas-like properties of the SFC mobile phase, diffusion of the sample band is higher than
in liquid chromatography. Although standard HPLC columns can be used for SFC, higher speed and
performance can be achieved with dedicated columns.
Separation of the same three analytes in different
columns shows that retention behavior differs
significantly according to the column chosen.
Shimadzu's Shim-Pack UC
series offers a wide range
of column sizes (analytical
and preparative scale),
and packing materials,
to ensure a solution for
almost every analyte.
Improving efficiency
LabSolutions™ MD software
To reduce time-consuming and intimidating method optimization processes, Shimadzu has
developed the LabSolutions™ MD software. By configuring parameters, including mobile
phases and columns, analysis schedules are automatically generated, and optimal analytical
conditions are determined. This allows for simpler, more efficient and beginner-friendly
experimental design.
AQbD methods can significantly reduce the number of data points
needed for optimization – by up to 52%
Analysis with
Make analysis
Building of
automated
schedule based
Design Space with
switching of
on experimental
chromatogram
co-solvents,
design
simulation
columns and SFC
parameters
Transform your chromatography with SFC
SELECT COLUMNS
OPTIMIZE YOUR WORKFLOW
References
1.
Gros Q, Duval J, West C, Lesellier E. On-line supercritical fluid extraction-supercritical fluid chromatography (SFE-SFC) at
a glance: A coupling story. TrAC Trends in Analytical Chemistry. 2021;144:116433. doi:10.1016/j.trac.2021.116433
2.
Communications to the editor. The Journal of Organic Chemistry. 1962;27(2):700-706. doi:10.1021/jo01049a069
3.
Zosel K; Studiengesellschaft Kohle mbH. Process for the decaffeination of coffee. United States patent 4260639A. 1970.
Nexera UC UFMS System
LIQUID
GAS
PRESSURE (MPA)
