2-octanol extraction conditions

On the basis of data obtained the possibility of substrates distribution and their D-values prediction using the regressions which consider the hydrophobicity and stmcture of amines was investigated. The hydrophobicity of amines was estimated by the distribution coefficient value in the water-octanole system (Ig P). The molecular structure of aromatic amines was characterized by the first-order molecular connectivity indexes ( x)- H was shown the independent and cooperative influence of the Ig P and parameters of amines on their distribution. Evidently, this fact demonstrates the host-guest phenomenon which is inherent to the organized media. The obtained in the research data were used for optimization of the conditions of micellar-extraction preconcentrating of metal ions with amines into the NS-rich phase with the following determination by atomic-absorption method. 

Such ion-pair constants are conditional , in that they depend on the concentration of the counterion with which the charged drug molecule enters into the octanol phase as an ion-pair. This is due to the low dielectric property of octanol, inducing charge neutrality upon uptake of charged drug molecules. Extraction constants may be used to explicitly include the participahon of the counterion [18]. 

Kawata et al. [ 128] have described the effects of headspace conditions on recoveries of volatile organic compounds from sediments and soils. Hewitt [129] compared three vapour partitioning headspace and three solvent extraction methods for the preparation of soil samples for volatile organic carbon determination in soils. Methanol extraction was the most efficient method of spiked volatile organic carbon recovery, which depended on the soil organic carbon content, the octanol-water partitioning coefficients of analytes and the extraction time. 

Several studies have been conducted on the stability of selected plastics additives for food contact in EU aqueous, fatty and alternate stimulants. Thus, Simoneau and Hannaert [17] showed that bis(2-ethylhxyl)phthalate plasticiser and octadecyl 3-(3,5-di-ter -butyl 4-hydroxy phenyl) propionate antioxidant are quite stable under all heat exposure conditions tested (20-40 °C, 1 h to 10 days) and all food simulents used (15% ethanol, 95% ethanol, 3% acetic acid, olive oil and iso-octanol). In these tests, the amounts of additives remaining in the plastic at the end of the test were between 90% and 107% of the amounts present in the plastic before extraction. 

The coacervation extraetion has been employed for the phase separation of ionic smfactants, and it is induced by other conditions such as the presence of HCl (pH induced coacervation) for anionic surfactants [231] or the presence of saturated sodimn chloride and 1-octanol for cationic surfactants [232]. The separation of anionic surfactants into two isotropic phases in an acid medium takes plaee at room temperature. The main advantages of this approach are the absenee of UV ehromophore groups in alkylsulfate or alkylsulfonate molecules of ionic surfactants, the laek of time and temperature dependence in the extraction-preconeentration step, the speed of extraetion, and the ability to extraet thermally labile and polar eompoimds. An important disadvantage is the utilization of quite acidic conditions,... 

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