Simultaneous determination of phthalate plasticizers in PVC packaging materials using homogeneous-ultrasonic extraction-GC-MS assisted with continuous wavelet transform

Plasticizers in PVC plastic films were extracted by homogeneous-ultrasonics using n-hexane, the extracted multiple phthalate plasticizers (PAEs) were simultaneously determined by GC-MS assisted with continuous wavelet transform (CWT), and then a novel method for simultaneous determination of multiple plasticizers in PVC packaging materials was established. While using the traditional GC-MS analysis to determine nine plasticizers in PVC packaging materials, the total ion current (TIC) chromatogram of diisononyl ortho-phthalate (DINP) and diisodecyl ortho-phthalate (DIDP) were seriously overlapped. For resolution of the overlapped and lower signal-to-noise ratio (SNR) TIC peaks of DINP and DIDP, twice CWT with symlet 2 (sym2) and scale parameter a = 30 was adopted. The results show that the overlapped noisy peaks of DINP and DIDP were successfully resolved with the SNR increasing more than 10 times, and the extraction efficiencies of PAEs increasing 18-29% compared to that of using ultrasonic extraction procedure. The proposed homogeneous-ultrasonic extraction GC-MS-CWT procedure provides an alternative novel way for simultaneous determination of multiple phthalate plasticizers in PVC packaging materials.