Determination of phthalates in wine by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Use of deuterated phthalates as internal standards

This study proposes the use of deuterated phthalates as internal standards for the accurate determination of phthalates in wine by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Unlike other internal standards proposed previously such as benzyl benzoate, deuterated phthalates enabled matrix-error free determinations to be performed without standard addition because statistically equal slopes were obtained for synthetic, white, rose and red wines. The relative standard deviation values under intermediate precision conditions ranged from 0.24 to 4.6%, and detection limits below 35 ng L(-1) were obtained. Recovery values were around 100% in most of cases and the method provided similar results to standard addition. Finally, the method was used to screen phthalate levels in 10 wine samples.