Temperature dependent properties of environmentally important synthetic musks

Abstract

Environmental fate determining physical properties including their temperature dependence for five nitro musks and for seven polycyclic musks were estimated. The properties evaluated were vapor pressure in a solid and liquid state (PS and PL), solubility in water (S), Henry's law coefficient (H = PL/S) and log octanol-water partition coefficient (log KOW). Gas chromatography for starting values of vapor pressure estimation and HPLC experiments at 5-20 degrees C for comparison of the theoretical versus experimental solubilities in water were performed. The values of temperature (T) dependence coefficients (Ai and Bi) in equations: log (Property)i = Ai - Bi/T were determined. Values of properties were compared with literature-based data, and an example of their use in environmental hazard estimation by fate modeling was given.

Estimation of vapour pressure, solubility in water, Henry’s law function, and Log Kow as a function of temperature for prediction of the environmental fate of chemicals

“…Thirdly, our research group contributed in the evaluation and chromatographic validation of the temperature-dependent properties, including also LogKow, of twelve environmentally important synthetic musks. There, also an example of automatic use of temperature correction coefficients in risk estimation by modelling was presented [10].…”

“…(2) for liquid state vapour pressure Pl from one known value (Pl 1 at T 1 ) with no other approximations needed than structure parameter K F . It was adopted in our program VPLEST to derive Apl and Bpl coefficients [10] by regression at given temperature (from 0 to +30 O C as the usual environmental range). Comparison of Pl assessments by VPLEST and gas chromatography [13] Comparison of Pl values determined by QSAR program VPLEST by author and gas chromatography by Lei et al [13].…”

“…Unfortunately, all their results are only for one temperature (25 O C). WATSOLU program is our modification of Ruelle's equations [16,17] to consist of separate temperature non-dependent and dependent parts for calculation of As and Bs coefficients to use in eqn (5) and first applied to the As and Bs evaluation for selected POPs [8] and synthetic musks [10] …”

“…The procedure was to subtract solubility equations for Log S in water-saturated n-octanol and in pure water from each other, which resulted to equation of Log Kow. We isolated temperature independent and dependent parts from these equations to produce coefficients Aow and Bow in eqn (10). Most temperature dependence was eliminated by subtraction, but some remained by polyfunctional molecules.…”

“…We learnt that ambient temperature was an essential factor in all model predictions of the fate of chemicals in the environment, but automatic temperature corrections of physical and chemical properties of the target substances were absent in their program codes. These procedures were, first time, taken in to our FATEMOD where all temperature dependent physical (Pl, S, H and Log Kow) and chemical (degradation life-times) properties of chemical ( Figure 1) were instantly corrected to the ambient temperature [9][10][11]. Development of these temperature adjustments and their applications in PEC modelling is reviewed in this paper.…”