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The
SIChrom™ liquid chromatography system
is the first commercial LC instrument based on the concept of sequential
injection and programmable flow. The instrument features a simple
and robust construction, consisting of a single pump and a single valve.
Such a design makes the operation of the chromatograph intuitive and
easy for the operator to understand as well as troubleshoot. The
sequential injection concept, in turn, allows the instrument to perform
liquid manipulation
with unprecedented
versatility, as each sequence of separation protocol can be executed at
an optimized individually tailored flow rate.
Although HPLC is a workhorse in many laboratories, systems typically
consist of large bench-top devices, with high power consumption
requirements, and lengthy auxiliary operations prior to and after each
separation run. By integrating several evolving technologies, the
SIChrom system has been designed to allow HPLC analyses at
accelerated rates and conducted at much lower pressures (<700 PSI).
This at a lower instrument cost and size, and without sacrificing
performance.
It is the combination of two components that make SIChrom system unique:
Flow programming
Use of sol gel monoliths
Flow
programming provides an unprecedented versatility in the choice of
injected sample and eluant volumes and of sequence of their loading on
the column. By changing flow rates, main operations like sample loading
and analyte separation can be carried out at optimized speed, while
auxiliary operations, like column chromatography and column washout can
be accelerated. An example is the "dilute and shoot" technique that is
optimized and fully automated by means of programmable flow.
Sol-Gel
Monoliths
are a novel type of HPLC columns manufactured by, e.g.,
Phenomenex and
Merck. In contrast to conventional HPLC columns, the sol-gel
monoliths are formed as a single piece of porous silica, having a higher
porosity than conventional particulated
columns. Merck reports a 15% greater porosity for their Chromolith
columns over conventional columns. Consequently, column backpressure is
substantially reduced allowing higher flow rates and faster throughputs.
Monolith sol-gel columns show good separation performance at lower
pressures, a critical feature that is integral to the SIChrom
performance. Monolithic columns that use reverse phase are most popular
and they have found many applications including separation
of pharmaceuticals, proteins, oligonucleotides, organic acids, and
enantiomeric compounds. Monoliths with ion exchanger sites found
application in ion chromatography.
Advantages
Over
Traditional HPLC
Price
The SIChrom system is less
than half the price of a typical full featured HPLC system.
Size & Construction
 The
SIChrom system is very compact, using up little valuable bench space and
allowing for a high degree of portability.
The construction is simple, consisting of a single pump and a single
valve. The lack of complex parts translates into unrivaled robustness.
Traditional HPLC systems contain 2-4 check valves (which are "the most
problematic part of an LC system", according to an article in LCGC
Magazine Feb 2006). The SIChrom instrument utilizes an innovative design
with no check valves. This means less downtime, less troubleshooting,
and no need for routine replacement of ~ $100/ea parts.
Ease
of Use
The SIChrom manifold is
uniquely transparent (literally!). As a consequence, its configuration
and operation is easy to understand, easy to troubleshooting, and easy
to operate.
Sequential Injection
- The SIChrom system is the first commercial liquid chromatograph based
on the concept of sequential injection. This is a powerful liquid
manipulation technique to automate traditional wet chemical assays.
Despite its ideal compatibility with liquid chromatography, sequential
injection could not be utilized in LC until the availability of
monolithic columns allowed high resolution chromatography to be carried
out at low/moderate pressures.
- Traditionally, simple LC systems comprising one pump and one valve can
only perform the simplest “inject and detect” kind of isocratic liquid
chromatography. Thanks to the sequential injection capability, the
SIChrom instrument can be built using an equally affordable and robust
physical design, but yet be able to perform complex liquid manipulation
operations. Capabilities inherent in the SI platform include:
sample focusing, precolumn derivatization, and even limited gradient
elution.
- In addition to being a laboratory instrument, the SIChrom system is
ideal for process control applications. It is robust, can be
remotely controlled, has small reagent consumption and generates very
small volume of waste.
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The SIChrom™ System
Close up of the Eight Port Lab-On-Valve®
Manifold made from Chemical Resistant Ultem
SIChrom system
uses Sol-Gel Monolith "Onyx" Columns
Onyx Technology
Advantages & Benefits
Solutions & Applications
Specifications
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Pressure: Up to 700 PSI
-
Flowrate: 0.006 to 9.0 ml/min
-
Software:
FIAlab for Windows
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Size: 10x9x9in
(25.4x22.9x22.9 cm)
-
Detector (optional):
USB4000 Spectrometer
(190 to 850 nm)
-
Detector
(optional):
PMT-FL
for Fluorometric Assays
-
Wetting Surfaces: Ultem®,
Teflon®, KelF®
-
Manifold: FIAlab Lab-On-Valve®
Time saving advantage
- The SIChrom system is extremely quick and easy to
learn.
Translated - considerable time savings in
operator training.
- The lack of extensive plumbing means quick mobile
phase exchange.
Translated - time savings in method development.
- Due to its simple design, the instrument is fast to
start up and power down. Translated - time
savings in daily routine use.
- Monolith Columns produce substantially reduced
backpressure allowing higher flow rates and faster
throughputs. Translated -
potentially many more samples assayed per hour.
Acknowledgement:
The pioneering works of Satinsky et. al., introduced Sequential
Injection Chromatography and demonstrated its performance on abanlysis
of components of pharmaceutical preparations. Their seminal work
describes separation of methylparaben (MP), propylparaben (PB),
butylparaben (BP) and sodium dichlofenac (SD) on Merck Speed rod
Chromolith Column equivalent to a typical C-18 5 mm particulate HPLC
liquid chromatography column. (Šatínský D., Solich P., Chocholouš P.,
Karlíček R.: MONOLITHIC COLUMNS – A NEW CONCEPT OF SEPARATION IN THE
SEQUENTIAL INJECTION TECHNIQUE, Anal. Chim. Acta, 499 (2003) 205-214). |