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.

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.

The SIChrom™ System

Close up of the Eight Port Lab-On-Valve^® Manifold made from Chemical Resistant Ultem

 Example of SIChrom Performance.

Chromatogram shows separations of guaifenesin, benzoic acid and dextromethorphan from the SIChrom LC instrument. Sample is injected into an eluent stream in a normal isocratic fashion. Specifics: Separation of guaifenesin (1), benzoic acid (2) and dextromethorphan (3). Column: Merck Chromolith RP18e 25 x 4.6 mm. Eluent:  H20: methanol  55:45 with 25 mM trifluoroacetic acid.

Onyx Technology

• Bimodal Pore Structure

• Monolithic vs. Particle-Based Structure

• Sorbent Characteristics

Advantages & Benefits

• High Sample Throughput

• Flow Flexibility

• Low Backpressure

• Dilute & Shoot

Solutions & Applications

• Amino Acids  (pdf file)

• By Industry (links  to Phenomenex Website)

• By Sample (links  to Phenomenex Website)

Specifications

• Pressure:  Up to 700 PSI

• Flowrate:  0.006 to 9.0 ml/min

• Software: FIAlab for Windows

• 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^®

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).