UPLC-MS/MS Determination of 18 Phthalates in Food Packing Materials

UPLC-MS/MS was applied to the determination of 18 phthalate esters in food packing materials. Sample of food packing material was extracted with n-hexane. Separation was performed on Aglilent ZDRBAX RRHD Eclipse Plus C18 column (3.0 mm×100 mm, 1.8 μm) connected in series with ZORBAX Eclipse Plus C18 column (2.1 mm×50 mm, 1.8 μm). Mixtures of 0.1% (φ) fomic acid solution and methanol mixed in different ratio were used as mobile phase in gradient elution. ESI+ and multi-reaction monitoring were adopted in MS/MS. Linear relationships between values of peak area and mass concentration of the 18 phthalates were kept in the same range of 0.050-5.0 mg·L-1, with detection limits (3S/N) in the range of 0.003-0.030 mg·kg-1. Tests for recovery were made by standard addition method at the concentration levels of 0.1,1.0,10.0 mg·kg-1, giving values of recovery and RSD′s (n=6) in the ranges of 87.5%-102% and 0.90%-3.9% respectively.