LAUSR

There is increasing scientific interest in the environmental pollution and public health of organophosphate esters (OPEs). Using liquid chromatography coupled to a hybrid quadrupole orbitrap high-resolution mass spectrometer (LC-Orbitrap-HRMS), a novel, robust and untargeted screening strategy for the identification of novel OPEs in indoor dust samples was presently developed based on the characteristic molecular fragmentation pathways, and twelve previously reported OPEs and six previously unrecognized OPEs were detected in the combined extracts of indoor dust samples, collected in Nanjing, eastern China. One of the six detected OPEs, bis-(2-ethylhexyl)-phenyl phosphate (BEHPP), was identified by comparison of unique LC and MS characteristics with a synthesized pure standard. Accurate concentrations of BEHPP were determined in n = 50 individual indoor dust samples with 100% detection frequency with a median concentration range of 50-1530 ng/g dry weight, that were generally greater or at least comparable to traditional OPEs, i.e. triphenyl phosphate (TPHP) and 2-ethylhexyl diphenyl phosphate (EHDPP), in the same dust samples. Statistically significant, positive correlations were found for log transformed concentrations of BEHPP versus EHDPP (r2 = 0.7884, p < 0.0001), and BEHPP versus tris(2-ethylhexyl) phosphate (TEHP; r2 = 0.4054, p < 0.0001), suggesting their similar commercial applications and sources in the environment.