Dotriacontane

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 7.9X10+8(SRC), determined from a structure estimation method(2), indicates that dotriacontane is expected to be immobile in soil(SRC). Volatilization of dotriacontane from moist soil surfaces is expected to be a fate process(SRC) given an estimated Henry's Law constant of 2700 atm-cu m/mole(SRC), using a fragment constant estimation method(2). However, adsorption to soil is expected to attenuate volatilization(SRC). Dotriacontane is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2X10-7 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). A biodegradation oxygen consumption value of 7.8 ug/mL using a soil suspension(3) indicates that biodegradation of dotriacontane may be a slow environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 7.9X10+8(SRC), determined from a structure estimation method(2), indicates that dotriacontane is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 2700 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 6.2 hours and 8.4 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The estimated volatilization half-life from a model pond is more than 2 years if adsorption is considered (4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 16.06(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). A biodegradation oxygen consumption value of 7.8 ug/mL using a soil suspension(5) indicates that biodegradation of dotriacontane may be a slow environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dotriacontane, which has an estimated vapor pressure of 2X10-7 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase dotriacontane 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 9 hours (SRC), calculated from its rate constant of 4.22X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2). Particulate-phase dotriacontane may be removed from the air by wet and dry deposition(SRC). Dotriacontane does not contain chromophores that absorb at wavelengths >290 nm(3) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: Dotricantane is a higher n-alkane containing 32 carbon atoms (C32). It is used in research. HUMAN EXPOSURE AND TOXICITY: There are no data available. ANIMAL STUDIES: Inhalation studies in cigarette-smoking baboons have been performed using (14)C-dotriacontane as a label for particulate matter. (14)C-dotriacontane was recovered from the lungs lavage. Samples of the pork, veal and chicken contained n-alkanes ranged from C12-C33.

Dotriacontane detections in plants used in food and medicinal applications(1). /Dotriacontane/[Table#8389]

n-Dotriacontane detections in plants used in food and medicinal applications(1).[Table#8390]

Using a structure estimation method based on molecular connectivity indices(1), the Koc of dotriacontane can be estimated to be 7.9X10+8(SRC). According to a classification scheme(2), this estimated Koc value suggests that dotriacontane is expected to be immobile in soil.

URBAN/SUBURBAN: Dotriacontane was detected in particulate air samples from Georgia Tech campus, GA at mean concentrations of 0.5 and 0.9 ng/cu m for summer 2005 and winter 2006, respectively(1). A mean dotriacontane concentration of approximately 5 ng/cu m was reported in the particulate phase of air samples collected in an urban and industrialized area in Prato, Italy during 2002(2). Dotriacontane concentration were 7.3 and 5.1 ng/cu m in particulate phase in the summer and winter, respectively; concentrations of 0.7 and 0.6 ng/cu m were detected in the vapor phase in summer and winter, respectively; samples were collected in an urban area in Nagoya, Japan in 1991(3).

RURAL/REMOTE: Dotriacontane was detected in particulate air samples from a rural area of Yorkville, GA at mean concentrations of 0.08 and 0.38 ng/cu m for summer and winter, respectively(1).

SOURCE DOMINATED: Dotriacontane was detected in particulate air samples from an interstate highway in Georgia at a mean concentration of 0.61 and 1.27 ng/cu m for summer and winter, respectively(1). Dotriacontane was detected at 25-190 pg/cu m with a mean of 93 pg/cu m in particulate air samples collected near a highway in Raleigh, NC; concentrations in samples collected 275 meters from the highway contained 20-240 pg/cu m with a mean of 80 pg/cu m(2).

AEROBIC: Oxygen consumption of 7.8 ug/mL over 10 days was reported for dotriacontane using a soil suspension of Hudson-Collamer silt loam soil incubated in the dark at 25 °C(1).

PURE CULTURE: Using 5 different marine bacterial strains and 4 different nitrogen sources, biodegradation of petroleum oil was examined under aerobic conditions at 26 °C for 10 days. Data reported for similar long chain alkanes, hexacosane (C26), octacosane (C28), and triacontane (C30), which were present as components of the petroleum oil, indicate that these compounds were degraded by 4 of 5 bacterial strains with certain nitrogen sources and consumption ranged from 5 to 96%(1). Other long chain alkanes such as dotriacosane (C32) may behave similarly(SRC).

An estimated BCF of 3 was calculated in fish for dotriacontane(SRC), using an estimated log Kow of 16.06(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for dotriacontane is estimated as 2700 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that dotriacontane is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 6.2 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 8.4 days(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The volatilization half-life from a model pond is greater than 2 years when adsorption is considered(3). Dotriacontane's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Dotriacontane is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2X10-7 mm Hg(SRC), determined from a fragment constant method(4).