Direct probe atmospheric pressure photoionization/atmospheric pressure chemical ionization high-resolution mass spectrometry for fast screening of flame retardants and plasticizers in products and waste

Abstract

In this study we develop fast screening methods for flame retardants and plasticizers in products and waste based on direct probe (DP)-atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI) coupled to a high resolution time-of-flight mass spectrometer (HR-TOF-MS). DP-APPI is reported for the first time in this study and DP-APCI, that has been scarcely exploited, is optimized for comparison. DP-APPI was more selective than DP-APCI and also more sensitive for the most hydrophobic compounds. No sample treatment was necessary and only a minimal amount of sample (few milligrams) was used for analysis that was performed within a few minutes. Both methods were applied to the analysis of plastic products, electronic waste and car interiors. Polybrominated diphenylethers (PBDEs), new brominated flame retardants (BFRs) and organophosphorus flame retardants (PFRs) were present in most of the samples. The combination of DP with HR mass spectra and data processing based on mass accuracy and isotopic patterns allowed the unambiguous identification of chemicals at low levels of about 0.025 % w/w. Under untargeted screening, resorcinol bis(biphenylphosphate) (PBDPP) and bisphenol A bis(bisphenylphosphate) (BPA-BDPP) were identified in many of the consumer products of which literature data is still very limited.