Suspect and Non-Targeted Analysis of Organophosphate Esters in Plastic Consumer Products via Ion Mobility Spectrometry-Mass Spectrometry

Abstract

Organophosphate esters (OPEs) are widely used as plasticizers and flame retardants in plastic products, posing critical environmental and human health risks. Traditional liquid chromatography-high resolution mass spectrometry (LC-HRMS) approaches face trade-offs between comprehensive coverage and spectral purity. This study established an advanced multidimensional identification framework utilizing LC coupled with cyclic ion mobility spectrometry and quadrupole time-of-flight mass spectrometry (LC-cIMS-QTOF). An integrated screening workflow merging targeted analysis, suspect screening, and nontargeted analysis (NTA) was deployed to characterize the OPEs in consumer plastics. A total of 63 OPEs were successfully characterized across seven polymer types, with 10, 22, and 31 compounds identified via targeted, suspect, and NTA workflows, respectively. Notably, 14 OPEs were traced back to the transformation products of phosphite antioxidants, ethoxy-linked OPEs constituted another predominant class with 22 congeners. This comprehensive characterization enriches current knowledge regarding the diversity of OPEs within plastic products, providing critical target lists for future migration and exposure assessments. Methodologically, the benefits of IMS, including providing cleaner mass spectra, discriminating isomers, and improving confidence levels, were demonstrated throughout the OPEs identification workflow. This established multidimensional screening strategy serves as a robust and efficient tool for uncovering OPEs contaminants in both plastic matrices and broader environmental media.