Recognition of Organophosphate Esters (OPEs) in the Sediment of 12 Lakes in the Taihu Lake Basin of China

Organophosphate esters (OPEs) have been frequently detected in various environmental matrices. However, there is a lack of investigation on comprehensively screening for potential OPEs from the known to the unknown, especially for the ones in surface sediments, which play an important role in the fate of OPEs in the environment. Thus, target, suspect, and nontarget screening of OPEs in n = 65 surface sediments from 12 lakes around Taihu Lake was investigated by a developed strategy of ultrahigh-performance liquid chromatography with Q Exactive hybrid quadrupole-Orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) in this study. For target screening, 17 OPEs were detected in 5-100% of the sediment samples with n-ary sumation 20OPEs (sum of the OPE concentrations) ranging from 34.8 to 623 ng/g dw (median of 106 ng/g dw). Surprisingly, tris(2,4-di-tert-butylphenyl)phosphate (TDTBPP, median of 72.1 ng/g dw) was the dominant OPE congener with a DF of 100%. For suspect screening, 16 OPEs were successfully identified. Interestingly, (2,4-di-tert-butylphenyl)pentaerythritol phosphatenovel (mBDTPDP, median of 5.51 ng/g dw, DF of 100%) and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphate (BDTPDP, median of 3.46 ng/g dw, DF of 78.0%) were the two most frequently detected ones. Beyond that, three unknown peaks were detected for the nontarget screening method, while tridodecyl phosphate (TDP) showed high abundance in 12 lakes (median of 0.59 ng/g dw, DFs of 86%), which may be additives applied in cosmetics. These results indicate that some unreported OPE congeners are ubiquitous in sediment samples, which were unfortunately overlooked previously.