| 環境中動態 | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 38(SRC), determined from a structure estimation method(2), indicates that N,N-dimethyl-p-benzenediamine is expected to have very high mobility in soil(SRC). The pKa of N,N-dimethyl-p-benzenediamine is 6.59(3), indicating that this compound will exist partially in the cation form in the environment and cations generally adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Aromatic amines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group(5,6)therefore, mobility may be much lower in some soils(SRC). N,N-Dimethyl-p-benzenediamine is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7.91X10-3 mm Hg(SRC), determined from a fragment constant method(7). Volatilization of the neutral species of N,N-dimethyl-p-benzenediamine from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.0X10-8 atm-cu m/mole(SRC), using a fragment constant estimation method(7). N,N-Dimethyl-p-benzenediamine is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7.9X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Biodegradation data in soil were not available(SRC, 2014).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 38(SRC), determined from a structure estimation method(2), indicates that N,N-dimethyl-p-benzenediamine is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 3.0X10-8 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). N,N-Dimethyl-p-benzenediamine in the water column may be susceptible to photo-oxidation via hydroxyl and peroxy radicalshalf-lives for these photo-oxidations may be on the order of 19-30 sunlight hours(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from an estimated log Kow of 1.25(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2014).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), N,N-dimethyl-p-benzenediamine, which has an estimated vapor pressure of 7.9X10-3 mm Hg at 25 °C((SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase N,N-dimethyl-p-benzenediamine is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC)the half-life for this reaction in air is estimated to be 2 hrs(SRC), calculated from its rate constant of 2.0X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). N,N-Dimethyl-p-benzenediamine contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC). |
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