FluoroFlash® SPE Cartridges for Fluorous Separations

The separation of fluorous compounds from non-fluorous compounds using FluoroFlash® silica gel is the central theme of fluorous techniques. Fluorous solid phase extraction (F-SPE) is used for quick separations of reaction mixtures involving FluoroFlash tags, scavengers, and reagents. The separation of fluorous compounds by F-SPE is a reliable and generic procedure that resembles filtration more than chromatography. The facile separation depends primarily on the presence or absence of a light fluorous tag, not polarity or other molecular features that control traditional chromatography.

A simple two-step separation involves the loading of a reaction mixture containing the fluorous-tagged molecule onto an F-SPE cartridge, washing the non-fluorous compounds away using a fluorophobic wash (typically 80:20 MeOH:water), then washing off the fluorous compounds with a fluorophilic wash, such as MeOH or THF. No fluorous solvents are necessary. The cartridge can be regenerated by washing with acetone or THF. Loading capacity for F-SPE cartridges is between 5-15% by weight of fluorous silica gel.

Fluorous Solid Phase Extraction Dye Demonstration

A visual representation of the FluoroFlash solid phase extraction technique illustrates the easy separation of a fluorous-tagged product from the non-fluorous compounds through the use of colored dyes.

• A mixture of a non-fluorous dye and a fluorous dye is loaded onto the F-SPE cartridge 
• Non-fluorous dye is washed off with a fluorophobic solvent wash, 80:20 MeOH:water. (middle test tube) 
• Fluorous dye is washed off with a fluorophilic solvent wash, MeOH. (right test tube)

A detailed F-SPE Application Note can be found at the Sigma-Aldrich® website portal: sigma-aldrich.com/fluorous.

Fluorous Solid Phase Extraction Dye Demonstration

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Benefits of FluoroFlash SPE separations


• High selectivity
• Simple binary separation 
• Large loading capacity 
• No fluorous solvents needed 
• Cartridges recyclable up to 10 times 
• Automation compatible

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