Discovery of Three Organothiophosphate Esters in River Water Using High-Resolution Mass Spectrometry

Abstract

Records of the environmental occurrence of organothiophosphate esters (OTPEs), which are used as flame retardants and food and industrial additives, are unavailable. In this study, we discovered three OTPEs, namely O,O,O-tris(2,4-di-tert-butylphenyl) phosphorothioate (AO168S), O-butyl O-(butyl-methylphenyl) O-(di-butylphenyl) phosphorothioate (BBMDBPt)/O,O-bis(dibutylphenyl) O-methyl phosphorothioate (BDBPMPt), and O-butyl O-ethyl O-hydrogen phosphorothioate (BEHPt), in the surface water of the Yangtze River Basin by applying a characteristic phosphorothioate fragment-directed high-resolution mass spectrometry method. Among the 17 water samples tested, the detection frequencies of AO168S and BEHPt were 100% and that of BBMDBPt/BDBPMPt was 29%. The mean concentration of AO168S was 56.9 ng/L (30.5–148 ng/L), and semi-quantitative analysis revealed that the mean concentrations of BEHPt and BBMDBPt/BDBPMPt were 17.2 ng/L (5.5–65.4 ng/L) and 0.8 ng/L (<the limit of quantification, LOQ, to 6.3 ng/L), respectively. Twelve organophosphate esters were also detected, of which the highest mean concentration was found for tris(2,4-di-tert-butylphenyl) phosphate (AO168O, 366 ng/L), followed by triphenyl phosphate (84.3 ng/L), triethyl phosphate (19.3 ng/L), and tributyl phosphate (15.7 ng/L). The Spearman’s correlation coefficient between AO168S and AO168O was 0.547 (p < 0.05), suggesting that AO168S commonly transforms into AO168O or that these chemicals have a similar source and behavior in the environment. Future studies are warranted to assess the potential toxicity, environmental behavior, and health risks posed by OTPEs.

Unregistered Hexaphenoxycyclotriphosphazene and Its Metabolite Antagonize Retinoic Acid and Retinoic X Receptors and Cause Early Developmental Damage

“…The detected concentration was relatively low when compared to the no observed adverse effect level of 3.7 ng/L, which was estimated by the lowest observed adverse effect level considering an uncertainty factor of 10. In our previous paper, we analyzed TPhP in the same water samples, which gives us a chance for comparison. HPCTP was lower than that of TPHP (0.4–473 ng/L with a median concentration of 23.2 ng/L).…”

Discovering Novel Organophosphorus Compounds in Wastewater Treatment Plant Effluents through Suspect Screening and Nontarget Analysis

“…Nontarget screening was performed using 14 characteristic fragments compiled from the literature ,, and identified suspect compounds (Table S4). In ESI+ mode, 10 fragments were included: triphenyl phosphate ion (C 18 H 16 O 4 P + ), cresyl phenyl phosphate ion or methyl diphenyl phosphate ion (C 13 H 14 O 4 P + ), cresyl phenyl phosphate dehydrated ion (C 13 H 12 O 3 P + ), diphenyl phosphate ion (C 12 H 12 O 4 P + ), diphenyl phosphate dehydrated ion (C 12 H 10 O 3 P + ), monophenyl phosphate ion (C 6 H 8 O 4 P + ), phosphate ion (H 4 O 4 P + ), phosphorothioate ion (H 4 O 3 PS + ), ethylphosphonate ion (C 2 H 8 O 3 P + ), and methylphosphonate ion (CH 6 O 3 P + ).…”

“…Nontarget screening was performed using 14 characteristic fragments compiled from the literature 30,31,34 and identified suspect compounds (Table S4 using Xcalibur Qual Browser (Thermo Scientific) to extract MS/MS chromatograms for these characteristic fragments in each isolation window with a mass tolerance of 5 ppm. Potential precursors were identified by searching the ions in the MS spectra or MS/MS spectra within the corresponding m/z range of the isolation window.…”

“…Over the past decade, suspect and nontarget screening strategies based on HRMS have uncovered more than 50 OPCs in various environmental matrices . This significantly enhanced our understanding of previously unrecognized OPCs. − For instance, Meng et al demonstrated the efficacy of functional group-dependent screening, revealing an abundant OPE bis­(2-ethylhexyl)-phenyl phosphate in indoor dust at levels comparable to or even higher than traditional OPEs. Additionally, eight novel OPCs were identified for the first time in rainfall runoffs and agricultural soils near a plastic recycling industrial park .…”

Comprehensive Characterization of the Transformation of Wastewater Effluent via Advanced Oxidation Processes Using Nontarget Mass Spectrometric Analysis

“…Organic micropollutants (OMPs), such as pharmaceuticals, pesticides, and industrial chemicals, are important emerging contaminants. Incomplete elimination of OMPs via traditional biological treatment processes results in their release into surface water. − Numerous OMPs, including perfluoroalkyl and polyfluoroalkyl substances, antibiotics, pesticides, and organothiophosphate esters, are frequently detected in surface water in the concentration range of nanograms per liter to micrograms per liter. − Considering the closed water cycle, OMPs can have long-term adverse effects on drinking water sources and aquatic ecosystems, leading to increased antibacterial resistance and endocrine disruption. , Therefore, reducing the load of the OMPs discharged from wastewater treatment plants (WWTPs) is necessary to protect aquatic ecosystems and drinking water supplies.…”