GC-MS Determination of 18 Phthalates in Urine with Separation by Solid-Phase Extraction

Eighteen phthalates (PTA′s) in urine were separated on a self-made SPE column made by packing a glass column with fillers of LC-C18, Envi-carb and PSA and mixing with a swirling mixer. Mixed istopic PTA′s (i.e. D4-DBP and D4-DEHP) were added as internal standards. After passing the urine sample through the SPE column, the column was eluted with n-hexane-ethylacetate (1+1) mixture. DB-5MS capillary column was used for chromatographic separation, and EI as well as SIM mode was adopted in MS analysis. Linear relationships between values of peak area and mass concentration were obtained in definite ranges with values of DL (3S/N) ranged from 0.002 5 to 0.005 mg·kg-1. Values of recovery found by standard addition method were in the range of 80.0%-120%, with RSD′s (n=6) ranged from 2.5% to 14%.