Figure 5: GC-MS SIM chromatogram (a) in comparison with the corresponding GC-MS/MS MRM chromatogram (b) in a tubing of medical infusion set containing bis(2-ethylhexyl) phthalate (DEHP) (1) and dioctyl terephthalate (DOTP) (2). SIM chromatogram shows an inconsistent high noise level and interfering peaks, and false-positive identification of di-n-octyl phthalate (DNOP) is represented by an asterisk in SIM chromatogram, but elimination is clear in MRM chromatogram.