Harrison Research Chromatotron 7924T Lab Centrifugal Thin-Layer Chromatograph

The Chromatotron is a preparative, centrifugally accelerated,
radial, thin-layer chromatograph.  It replaces prep TLC plates, small gravity columns, flash columns and HPLC.

Overall dimensions are 30x35x30 cm.

Principle of Operation: The sample to be separated is applied, as a solution, in the central area of a spinning disk coated with a thin layer of sorbent. Elution by solvent forms circular bands of the separated components which are spun off from the edge of the rotor together with solvent. A novel collection system brings the eluate to a single output tube.

• Capacity: Up to 500 mg per component, about 1-2 g total, e.g. dimethyl and diethyl phthalate in hexane – ethyl acetate  9:1 on a 4 mm layer of silica gel.
• Sorbents: Silica gel, alumina and silica gel – silver nitrate. Not useful with RP sorbents.
• Solvents: Compatible with all common chromatography solvents, including acetic acid. Not suitable for use with mineral acids.

Special Advantages:
* No “spotting” of samples or scraping of bands.
* Separations are completed rapidly, typically within 20 min.
* A UV transparent lid allows direct observation of UV absorbing or colored compounds during the separation.
* Layer thickness of 1, 2, 4 or 8 mm gives high capacity. The sorbent layer is easily regenerated in situ for reuse.
* Solvents are used sparingly. Gradient elution is easy. A nitrogen atmosphere prevents oxidation of samples.
* Compact (easily moved from lab to lab), few controls, no high pressures.
* Low price. Half a dozen Chromatotrons cost less than a single prep HPLC.

UV transparent compounds are detected in the eluted fractions by conventional TLC.

Connection to refractive index and UV monitors is not recommended.

May be used with a fraction collector although hand collection is adequate.

Examples of Separations:
1. Cyclopentanone and cycloheptanone 2,4-dinitrophenylhydrazones, 4 mg, on a 1 mm layer of silica gel. A UV monitor was used for detection. This monitor is not supplied and is not required for operation of the Chromatotron since UV absorbing bands are visualized on the rotor.

2. Strychnine and brucine (250 mg) on a 2 mm layer of silica gel. A UV lamp was used for detection. Bands on rotor are shown full size.

3. Dimethyl and diethyl phthalate (1g) on a 4mm layer of silica gel.

Model 7924T-01

The complete kit, catalog no. 7924T-01 consists of:
Chromatotron main unit, power supply for 100 – 240V 50/60Hz, Teflon funnel with support (for solvent supply), 5 glass rotors, tools for preparation of 1, 2,4 and 8 mm sorbent layers, flowmeter (for nitrogen), instruction manual, polyethylene cover and spare parts.

Other items not supplied but required for operation:
UV lamp, short wave. Any hand-held lamp will be suitable.
Silica gel (Sigma Aldrich silica gel TLC standard grade, item 288586 is recommended).
Calcium sulfate hemihydrate binder (plaster of Paris) should be obtained locally.