The worldwide generation of plastic electronic waste (e-waste) is reaching epic proportions. The presence of toxic brominated flame retardants (BFRs) within these materials limits their ability to be recycled, resulting in large amounts of e-waste reaching landfills.
Liquid extraction surface analysis mass spectrometry (LESA-MS) employing a chip-based nanoelectrospray coupled to a triple quadrupole mass spectrometer represents a novel control technology for directing e-waste streams for recycling. LESA-MS allows direct sampling and analysis of solid material, capable of detecting BFRs including polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBP-A), the two most common flame retardant additives currently in circulation.
Authentic PBDE congeners and TBBP-A were deposited on glass and characterised by LESA-MS analysis. PBDEs are notoriously difficult to detect via electrospray; however, they were detected with ease by utilising a combination of nanoelectrospray and solvent doped with ammonium acetate. In situ detection of TBBP-A within plastic e-waste was also possible by performing LESA-MS on the surface of granulated material provided by a commercial waste depot. E-waste sample analysis was completely automated, with each sample analysed in less than 1 min.
LESA-MS is fast, simple, and robust allowing unambiguous detection of a range of additives through tandem mass spectrometry. LESA-MS does not require dissolution of the solid matrix nor the sample to be present under vacuum and the use of separative techniques prior to analysis is not necessary.