Semiquantitative Nontargeted Screening of Organophosphorus Plastic Additives in Consumer Products Using ³¹P NMR

Mass spectrometry (MS) is typically employed for the nontargeted identification of unknown organophosphorus compounds (OPCs). However, quantitative analysis remains a major challenge due to the lack of authentic standards for most of the OPCs. A phosphorus NMR (³¹P NMR) method for semiquantitative nontargeted analysis was developed and applied to 37 different plastic products, where OPCs were detected in nine at high concentrations (86.9-7206 nmol/g). Three classes of compounds were detected with clearly separated chemical shifts, including organophosphites (δ = 125-140 ppm) and organophosphates (δ = (-20)-5 ppm), as well as an unexpected "unannotated" class (δ = 5-20 ppm). The "unannotated" class was subsequently identified as organophosphite diesters and confirmed through in-lab hydrolysis trials. In this work, we demonstrate how a ³¹P NMR method may serve as a powerful analytical tool when combined with mass spectrometry for the nontargeted analysis of OPCs. We highlight organophosphite diesters as a novel class of compounds which represent a potential source of organophosphate diesters in the environment.