Chiang Mai Journal of Science

A simple and environmental friendly method using headspace solid-phase microextraction (HS-SPME) determination of four phthalate esters in vegetable oil and soft drink samples were investigated. The extraction temperature, extraction time and desorption time were evaluated by comparing two types of commercial SPME fibers; polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber and polyethylene glycol (PEG) fiber. The PDMS/DVB fiber showed better response than PEG fiber. The linearity, limit of detection, repeatability and reproducibility were validated. The enrichment factor (EF) for oil samples and soft drink samples were in the range of 11-17, 37-848, respectively. The percentage recoveries by spiking samples with standard solution were also examined, the result found in the range of 84.5-102.1 % with the RSD less than 10 %. The proposed method was successfully applied for trace analysis of four phthalate esters in vegetable oil and soft drink samples.