Reaction of tris(2-chloroethyl)phosphate with reduced sulfur species

Abstract

Tris(2-chloroethyl)phosphates (TCEP) is a widely used flame retardant in the U.S. It has recently been identified as one of the most frequently detected contaminants in U.S. streams. This contaminant is of toxicological concern in sensitive coastal ecosystems such as estuaries and salt marshes. It is likely that reactions with reduced sulfur species such as polysulfides (Sn2−), bisulfide (HS−), and thiophenolate (PhS−) present in anoxic subregions of coastal water bodies could have a significant impact on rates of removal of such a contaminant. The kinetics of reaction of reduced sulfur species with tris(2-chloroethyl)phosphate have been determined in well-defined aqueous solutions under anoxic conditions. Reactions were monitored at varying concentrations of reduced sulfur species to obtain the second-order rate constants from the observed pseudo-first order rate constants. The determined second-order rate constant for the reaction of TCEP with polysulfide at 25°C is 5.0 (± 1.4) × 10−4 M−1 s−1, with thiophenolate at 50 °C is 34 (± 2) × 10−4 M−1 s−1 and with bisulfide at 50 °C is 0.9 × 10−4 M−1 s−1, respectively. In addition, the degradation products of hydrolysis and the reactions with polysulfides, thiophenolate, and bisulfide with TCEP were studied with GC-FID and LC-MS-MS and were quantified.

Environmental fate and effects of organophosphate flame retardants in the soil-plant system

“…However, Si and Al oxide minerals failed to exert a catalytic effect, indicating that OPFRs will persist in soil and aquifer systems dominated by these phases (Fang et al, 2018). Oxidation of OPFRs may also occur in soil, demonstrating that radical OH produced by pyrite activated persulfate could be an effective oxidant for the TCEP removal process (Saint-Hilaire et al, 2011;Lian et al, 2019).…”

Transformation of chlorpyrifos and chlorpyrifos-methyl in prairie pothole pore waters

“…30,31,50,54,55 Thiols constitute a portion of reduced sulfur and organic matter in marine and salt marsh sediments 54,56,57 and act as strong nucleophiles toward organic compounds. 24,58 Due to their demonstrated reactivity and prevalence in anoxic environments, organo-sulfur compounds could be a signicant factor inuencing the transformation of CPM in PPR wetland pore water.…”