Direct temperature resolved HRMS of fire-retarded polymers by in-source PyMS on an external ion source Fourier transform ion cyclotron resonance mass spectrometer

Rapid microscale analysis with high mass accuracy is demonstrated by direct temperature resolved desorption and pyrolysis from a Pt/Rh filament probe inside the external ion source of a 7-T FTICR-MS. High pressure generated during desorption and pyrolysis in the ion source does not interfere with analysis in the hydrocarbon free UHV of the ICR cell, thus allowing short observation cycles at high resolution. The typical conditions achieved, a mass resolution (m/Dm)50% equals 50 000 at m/z 600 with cycle times of 100 ms, were used to analyze isobaric compound mixtures generated by pyrolysis of brominated fire-retarded polymers spiked with antimony-containing synergists. Unknown fire-retarded polymer blends sampled from household appliances were found to contain brominated biphenyls, brominated diphenyl ethers, tetra bromoBisphenol-A and its butylated isomers, polystyrene, and antimony oxides. High-resolution temperature resolved analysis by "in-source" pyrolysis FTICR-MS conforms the elemental composition. The resolution is sufficient to separate the nominally isobaric ions from the antimony(III) oxide (Sb₄0₆) synergist and the n-butyl ether derivative of tetrabromoBisphenol-A.