Degradation of Three Trishaloalkyl Phosphates under Anoxic Condition in the Presence of Reduced Sulfur Species.

摘要

Tris(haloalkyl)phosphates are widely used flame retardant in the U.S. They have recently been identified as one of the most frequently detected contaminants in U.S. streams. These contaminants are 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 ( Sn-2), bisulfide (HS -), and thiophenolate (PhS-) present in anoxic subregions of coastal water bodies could have a significant impact on rates of removal of such contaminants. The kinetics of reactions of reduced sulfur species with three tris(haloalkyl)phosphates have been determined in well-defined aqueous solutions under anoxic conditions. Reactions were monitored at varying concentrations of reduced sulfur species to obtain second-order rate constants from the observed pseudo-first order rate constants. The reactivity of Sn-2, PhS -, and HS-, were compared in this work. The degradation products of hydrolysis and the reactions with polysulfides, thiophenolate, and bisulfide with tris(2-chloroethyl)phosphate (TCEP) were studied with GC-FID and LC-MS-MS and were quantified. In addition, the degradation products of hydrolysis and the reactions with polysulfides and thiophenolate, with tris(2-chloroisopropyl)phosphate (TCPP) and tris(1,3-dichloro-2-propyl)phosphate (TDCP) were quantified as well.