Extraction of alcohols into a xylene drop

A headspace microextraction into a single drop for the determination of alcohols in aqueous solutions is proposed. A drop of o-xylene containing butanone-2 as an internal standard is used for the extraction. The analytes are extracted by suspending a 3 μL extracting drop directly from the tip of a microsyringe fixed above the extraction vial such that the needle passes the septum and the needle tip appears above the surface of the solution. After the extraction is finished the drop is retracted back into the needle and injected directly into the GC instrument. The influence of the experimental conditions - sampling time, sampling temperature, stirring rate and ionic strength of the solution - on the extraction efficiency was investigated. The linear range and the precision are examined. The headspace single drop microextraction is applied for the analysis of beer.