Comparative study of thermal desorption and solvent extraction-gas chromatography-mass spectrometric analysis for the quantification of phthalates in polymers.

For the quantitative analysis of phthalates in polymers, a thermal desorption (TD)-GC-MS method was compared with solvent extraction (SE)-GC-MS methods which require the long pretreatment procedures using large amount of harmful organic solvents. Calibration curves of TD-GC-MS showed good linearity (r(2)>0.9997) and low method detection limit (<30mg/kg with 9.0% RSD). Quantification results for three kinds of test phthalate polymer samples (test PTPSs) showed an RSD below 7.4% and acceptable recoveries (78.3-117.4%) as in the standard method of International Electrotechnical Commission. Even in a sample with a high concentration of phthalates (PTPS #3), the method also showed good recovery with low RSD values. The TD-GC-MS results were comparable with those results by SE-GC-MS methods, indicating that TD-GC-MS method also can be used for the quantification of phthalates in polymers. The average recovery (92-103%) and RSD (<20%) values obtained from international inter-laboratory study for TD-GC-MS performed in six laboratories also indicated that TD-GC-MS can be used as an international standard method for the quantification of phthalates in polymers.