Determination of phthalate esters at trace levels in light alcoholic drinks and soft drinks by XAD-2 adsorbent and gas chromatography coupled with ion trap-mass spectrometry detection

An analytical method based on solid phase extraction (SPE) with XAD-2 for the enrichment of seven phthalate esters in light alcoholic drinks (alcohol content below 6% alc vol⁻¹) and in soft drinks has been developed using gas chromatography coupled with an ion-trap mass spectrometer detector (GC/IT-MS). The instrumental analytical protocol was found to yield a linear calibration in the range of 1–800 ng mL⁻¹ with r² values ≥ 0.912; the limits of detection (LOD) vary between 0.2 pg μL⁻¹ and 20 pg μL⁻¹, whereas the limits of quantification (LOQ) range between 0.6 pg μL⁻¹ and 41 pg μL⁻¹ with relative standard deviations (RSDs) of ≤4.8 and ≤5.5, respectively. The interday precision ranges between 3.6 and 6.3%, whereas the intraday accuracy is between 7.9 and 12.4%. This simple, reliable, reproducible and low-cost analytical method has been applied to several commercial light alcoholic samples such as beers and soft drinks. DEP (0.1–1.0 ng mL⁻¹), DiBP (0.2–2.5 ng mL⁻¹), DBP (1.9–4.4 ng mL⁻¹), BBP (0.08–0.8 ng mL⁻¹), DEHP (3.6–101 ng mL⁻¹) are present in every sample analyzed, whereas DMP (1.9 ng mL⁻¹) and iBcEP (0.08 ng mL⁻¹) are found only in one sample of beer.