THE CHROMATOTRON™

Centrifugal Thin-Layer Chromatograph

The Chromatotron is a preparative, centrifugally accelerated, radial, thin-layer chromatograph designed by the authors of the Compendium of Organic Synthetic Methods. It replaces prep TLC plates, small columns and HPLC.Overall dimensions are 30x35x30 cm.

 

 

Principle of Operation: 

The sample to be separated is applied, as a solution, near the center 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.

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Capacity: Up to 500 mg per component, 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.
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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.

 

Compounds without a chromophore 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.

 

References:

For applications, search for chromatotron on the Internet. Several thousand applications of the Chromatotron can be located by a Google Scholar search for chromatotron. Refine your search by including the specific substance or general class, e.g:

chromatotron alkaloid

chromatotron glycoside

chromatotron ibuprofen

chromatotron antioxidant

chromatotron enzyme inhibitor

chromatotron hiv inhibitor

chromatotron medicinal plants

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.

 

 

 

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 (1 g) on a 4 mm layer of silica gel.