Application of stir bar sorptive extraction to the determination of polycyclic aromatic hydrocarbons in aqueous samples.

The technique of stir bar sorptive extraction is used for the determination of polycyclic aromatic hydrocarbons (PAH) in aqueous samples. The PAHs are extracted with 10-mm stir bars (Gerstel Twister) coated with 0.5 mm polydimethylsiloxane and analyzed with a gas chromatography-mass spectrometry system.

Simultaneous determination of preservatives in beverages, vinegar, aqueous sauces, and quasi-drug drinks by stir-bar sorptive extraction (SBSE) and thermal desorption GC-MS.

A method for the simultaneous determination of seven preservatives - sorbic acid, benzoic acid, and p-hydroxybenzoic acid ethyl, isopropyl, propyl, isobutyl, and butyl esters - in beverages, vinegar, aqueous sauces, and quasi-drug drinks has been developed using the stir-bar sorptive extraction technique then thermal desorption GC-MS analysis. The extraction conditions - pH, sample volume, extraction temperature, salt addition, and extraction time - were examined. d5-Benzoic acid and p-hydroxybenzoic acid sec-butyl ester were added as surrogate internal standards to compensate for the effect of sample matrix and coexisting analytes on the sorptive extraction.