The determination of benzoic acid in lemon flavored beverages by Stir Bar Sorptive Extraction-CGC-MS

Stir Bar Sorptive Extraction (SBSE), a recently introduced solventless extr action technique, was applied for the enrichment of benzoic acid in lemon f lavored beverages. The stir bar is covered with 50 mg polydimethylsiloxane (PDMS) and the extraction mechanism is similar to that of solid phase micro extraction (SPME) but the enrichment factor is ca. 100 times higher. SBSE is followed by thermal desorption (TD)-capillary gas chromatography (CGC)-m ass spectroscopy (MS). Calibration graphs for benzoic acid were linear from 1 to 1000 ppm for water and diluted soft drinks and the repeatability (n = 6) was less than 5% RSD.