[Determination of trace phthalates in beer by gas chromatography coupled with solid-phase microextraction using a...

A method based on headspace solid-phase microextraction/gas chromatography (HS-SPME/GC) for the determination of phthalates (PAEs) in beer using benzoxy-C[6]/OH-TSO coated fiber was developed. A Taguchi's L25 (5(6)) orthogonal array design was employed to evaluate potentially significant factors and screen the optimum conditions for each analyte to ensure the highest extraction efficiency. The extraction for the determination of dimethyl phthalate (DMP) and diethyl phthalate (DEP) was carried out at 65 degrees C for 50 min with a constant stirring speed of 1,250 r/min, that of dibutyl phthalate (DBP) and diamyl phthalate (DAP) was at 95 degrees C for 50 min with a speed of 624 r/min, and that of the other PAEs was at 105 degrees C for 60 min without agitation. Owing to the good selectivity and high sensitivity of this new calixarene fiber, the method enabled the quantification of PAEs at low microg/L level in beer media with good precisions and recoveries. The survey of three bottled beer samples showed that DBP and bis(2-ethylhexyl)-phthalate (DEHP) were the main PAEs found in beer and total phthalates concentrations were between 6.22 and 7.76 microg/L. The migration tests revealed that the high content of DEHP incorporated in PVC gaskets in the lids could be a potential source of PAEs contamination in bottled beer during transportation and storage.