Twister Stir Bar Sorptive Extraction

Stir Bar Sorptive Extraction is a great way of recovering compounds responsible for flavours, aromas and off-odours in just about anything that can be eaten or drunk.

Twister is solvent free and recovers a broad spectrum of compounds from both liquid and gas phases enabling both flavour and aroma studies to be made with equal ease. Twister has big advantages over both liquid and solid phase micro extraction (SPME):

• No displacement effects. the large amount of phase on each stir-barSPME has only a small amount of phase and if a sample contains some major components then often this will be the only thing you see as the major components displace minor components from the fibre.
• No solvent peak to mask important components
• High recoveries aids the determination of trace components
• Stir bars can be reused many times

In liquid phase or headspace, the extraction process is simple and fool-proof, and once compounds have been recovered into the stir bar's poly dimethyl siloxane coating, there are stable enough to be stored or transported without losses. Offering the possibility of extracting samples in the field and analysing them centrally

Sample Extraction for GC and LC

The patented GERSTEL Twister is a magnetic stir bar that has been coated with a partitioning phase of poly-dimethyl siloxane (PDMS). While it is stirring the sample solution, the Twister efficiently extracts organic components from aqueous or other liquid samples or from the sample's headspace. After extracting analytes from the sample solution onto the Twister, compounds can be determined in two ways:

• For volatile compounds the Twister may be thermally desorbed to the GC column.
• For less volatile compounds the Twister can be solvent back extracted and injected into an LC or LCMS.

This solventless extraction technique provides quantitative analysis with extremely low detection limits (sub parts per billion), is reproducible from bar to bar and each bar can be re-used many times.

Advantages

• Solventless extraction
• Analyte recovery is predictable
• Quantitative analysis with low detection limits
• Reproducible
• Can be used in a wide variety of matrices
• Can be used many times