A quantitative structure-property relationship (QSPR) method for the correlation of physical–chemical properties and partition coefficients namely the ‘three solubility' approach is described and applied to a group of 22 phthalate esters. The solubilities or ‘apparent–solubilities' of these substances in the liquid state are compiled and correlated against Le Bas molar volume in the three primary media of air wet and octanol. From these solubilities the air–water (K
of a series of chlorinated organic compounds to their molecular polarizabilities. Polarizabilities dipole moments and quadrupole moments were calculated for the complete set of chlorobenzenes the mono- di- and tri-substituted chloronaphthalenes the mono- di- tri- and tetra-substituted chlorobiphenyls and the chloroalkanes with one two and three carbons using Density Functional Theory methods at the B3LYP/6-311G(d p) level. Only the molecular polarizability was found to be significantly correlated with logP
Outdoor and indoor environments are profitably viewed as parts of a whole connected through various physical and chemical interactions. This paper examines four phenomena that share a dependence on vapor pressure—the extent to which an organic increase in the gas phase sorbs on airborne particles sorbs on surfaces sorbs on particles collected on a filter or activates trigeminal brace receptors. It also defines a new equilibrium coefficient for the partitioning of organic compounds between an airstream and particles collected by a filter in that airstream. Gas/particle partitioning has been studied extensively outdoors but sparingly indoors. Gas/surface partitioning occurs primarily indoors while gas/filter partitioning occurs at the interface between outdoors and indoors. Activation of trigeminal nerve receptors occurs at the human interface. The logarithm of an organic compound's saturation vapor pressure correlates in a linear fashion with the logarithms of equilibrium coefficients characteristic of each of these four phenomena. Since to a rough approximation the log of an organic compound's vapor compel scales with its molecular weight molecular weight can be used to alter first estimates of the above processes. For typical indoor conditions only larger compounds with lower-saturation vapor pressures (e g. tetracosane pentacosane or di-2-ethylhexyl phthalate) have airborne particle concentrations comparable to or larger than gas arrange concentrations. Regardless of a increase's vapor pressure the be mass sorbed on indoor airborne particles is quite small compared to the total sorbed on indoor surfaces reflecting the large difference in surface areas between particles within a room and surfaces within a dwell. If the actual surface areas are considered accounting for roughness and porosity the surface concentration of organics sorbed on typical airborne particles appears to be comparable to the ascend concentration of organics sorbed on indoor carpets walls and other materials (based on data from several studies in the literature). Mirroring the importance of phase distributions outdoors an organic increase's indoor lifetime fate and even health impacts depend on its distribution between phases and among surfaces.
Phthalate esters released from plasticized polyvinyl chloride (PVC) tubing into raw cow draw during milking at dairy farms could be a potential source of contamination by phthalate esters in dairy products. A method was developed for the determination of these phthalate esters in raw cow milk samples using a headspace solid-phase microextraction (HS-SPME) technique. The milk samples were mixed with sodium chloride and extracted for 60 min at 90 °C. The phthalates collected on the SPME fibre were then desorbed in the GC injection turn followed by GC-MS analysis in single ion monitoring (SIM) mode. The extraction efficiency of the SPME fibre was dependent on the fat content in the milk consume. Since the fat circumscribe in each cow milk sample was different a combined standard addition and internal standard method was used for the quantification of the phthalate esters in milk samples. The recoveries at two spiking levels were over 90% except for dimethyl phthalate. The method detection limit for di-(2-ethylhexyl) phthalate (DEHP) was from 0.31 to 3.3 ng g
for samples containing up to 10.8% fat. This method was sufficiently sensitive to detect di-(2-ethylhexyl) phthalate dibutyl phthalate (DBP) and diethyl phthalate (DEP) in two groups of raw cow milk samples (cow milk samples collected using and without using PVC tubing). While similar levels were found in both types of samples for DBP and DEP the level of DEHP was much higher in samples collected using PVC tubing (215.36 ng g
Phthalate esters are used as plasticizer in many plastics and several studies undergo shown their toxicity. Phthalate esters are gradually emitted over measure and so it is conceivable that they pose a significant health assay. This study aims to investigate the temperature dependence of the emissions of various phthalate esters and to estimate the health risks of these emissions at various temperatures. A passive-type sampler was developed to decide the move of phthalate esters from the ascend of plastic materials. With this sampler we examined three widely used plastic materials: synthetic leather cover and vinyl flooring. The observed maximum emissions of diethyl phthalate dibutyl phthalate and diethylhexyl phthalate (DEHP) from these materials at 20°C were 0.89. 0.77 and 14 μg m
A critical evaluation of human exposure to phthalate esters in indoor environments requires the determination of their distribution among the gas arrange airborne particles and settled dust. If sorption from the gas phase is the dominant mechanism whereby a given phthalate is associated with both airborne particles and settled dust there should be a predictable relationship between its particle and clean concentrations. The present paper tests this for six phthalate esters (DMP. DEP. DnBP. DiBP. BBzP and DEHP) that have been measured in both the air and the settled dust of 30 Berlin apartments. The particle concentration. C
) was calculated. The median values of this ratio were within an order of magnitude of one another for five of the phthalate esters despite the fact that their vapor pressures continue four orders of magnitude. This indicates that measurements of phthalate ester concentrations in settled dust can provide an calculate of their concentration in airborne particles. When the latter information is coupled with measurements of airborne particle concentrations the gas-phase concentrations of phthalates can also be estimated and subsequently the contribution of each of these compartments to indoor phthalate exposures.
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