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| Eluant Distribution System* |
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Novel Centrifugal Technology Overcomes the Complexities and Inconvenience of Conventional SFC Fraction Collection
Modular SFC’s patent pending fraction collector technology provides HPLC-like fraction collector convenience for SFC applications. The novel centrifugal fraction collection system operates at atmospheric pressure and uses standard glass test tubes to capture the non-volatile components from the gaseous CO2 eluant stream with greater than 90% recovery.
The patent pending methodology is based on a rotor that spins at 1,500 rpm (concentrator speed)
and contains up to 24 disposable glass fraction collection tubes. Flexible tubing directs the eluant flow into each sample collection container in turn. The eluant tube dispenses eluant having volatile and non-volatile compounds (even solid precipitates) from the connected SFC system. The centrifugal force causes the highest density components (liquids and solids) to accumulate in the bottom of the collection container while allowing the expanded gaseous components to escape from the opening of the container. Vapors are directed through an exhaust hose to the nearest laboratory vent facility, eliminating the need for the fraction collector to occupy valuable space inside a hood.
WASTE/COLLECT and NEXT FRACTION controls are enabled by contact closure outputs on the SFC instrument and executed while the carrier is spinning at 1,500 rpm. Future versions will be internally programmable to operate these functions by time or by detecting peak height thresholds generated by an analog output from the SFC system’s detector.
* Centripetal vs. Centrifugal footnote:
The question is often asked, “Doesn’t centripetal, not centrifugal, force capture the non-volatile compounds in the collection containers?” The answer is that it all depends on the observer’s frame of reference.
When taking a hard right while driving, physics describes the car applying a “real” centripetal force to the driver to make the person change direction. Alternatively, the apparent feeling that the driver’s shoulder is pushing outwards on the car door is the “fictional” centrifugal force.
The bottom line is that 500 years of instrument naming convention has resulted in calling the laboratory equipment which performs density separations by spinning containers a centrifuge. Therefore, Centrifugal Fraction Collector is what everyone would expect the CFC-2 instrument to be called. Any other name would be a distraction. |
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