Rapid qualitative and semi-quantitative determination of polymer additives in polymermatrix by electrospray ionization-triple quadrupole mass spectrometry with accelerated solvent extraction (ASE–ESI-MS/MS)

Abstract

A rapid method for the qualitative and semi-quantitative determination of polymer additives was developed to determine a set of eight polymer additives used in plastic samples by accelerated solvent extraction–electrospray ionization-triple quadrupole mass spectrometry (ASE–ESI-MS/MS). The eight additives were Tinuvin 328, Tinuvin 770, Cyasorb 2908, Cyasorb 3853, Irgafos 168, Antioxidant 405, Irganox 565, Irganox MD 1024. In order to enable the fast identification of additives, an ESI-MS library for 100 additives was built. By using a molecular weight search of the library, and comparing the MS/MS spectra, additives in polymers can be easily identified. Moreover the additives can be quantified by ESI-MS/MS without a column separation step. ASE was used for sample preparation. Three static extraction cycles were carried out for 20 min per cycle at 1500 psi and 100 °C, using trichloromethane/acetone (1/1, v/v) as the extraction solvent, then the samples were washed with a 20% volume of the maximum bottle (66 mL) of extraction solvent. Finally the samples were purged with nitrogen for 100 s and re-dissolved in 1 mL methanol, diluted 100 times and 5 μL directly injected into the instrument for analysis. Limits of detection for the multi-reaction-monitoring mode of the ESI-MS/MS analysis varied from 0.1 to 10 ng mL⁻¹. The calibration curves were linear with R ≥ 0.993. The relative recoveries were between 84.0% and 120% with relative standard deviations (RSD, n = 6) lower than 20%. This quantification method was successfully used in the determination of additives in real samples. The method was confirmed by UPLC–MS/MS and the results were in excellent accordance.