Ionic organic compounds

The boiling points of ionic compounds are higher still, so high that most ionic organic compounds decompose before they boil. 

Uptake ofNon-Ionic Organic Compounds (NOCs).151... 

Reversed-phase chromatography is often used to separate both neutral and ionic organic compounds. In this section, some important aspects for the understanding of the behavior of ionic compounds in reversed-phase chromatography are discussed. The important concepts introduced here are the electrical double layer and the electrostatic surface potential. It will be shown that they are essential for the understanding of the elution profile of ionic compounds. These concepts are further explored in the next section where theoretical models for ion-pair chromatography are discussed. 

To conclude, we should also point out that condensed phases containing the organic compound of interest can be formed at the particle surfaces. Such phenomena occur in cases involving ionic organic compounds that form micelles/hemimicelles... 

Gawlik, B. M., et al., Alternatives for the Determination of the Soil Adsorption Coefficient, AToc, of Non-ionic Organic Compounds—A Review. Chemosphere, 1997 34(12), 2525-2551. 

Ionic organic compounds involving carbanions react readily with oxygen. For example, ethyl-sodium, C2Hj Na+, self-ignites in air. Ionic organometallic compounds are extremely reactive in water, as shown by the following reaction ... 

Lu, X., Tao, S., Hu, H., and Dawson, R.W., Estimation of bioconcentration factors of non-ionic organic compounds in fish by molecular connectivity indices and polarity correction factors, Chemosphere, 41, 1675-1688, 2000. 

Gawlik, B.M., Sotiriou, N., Feicht, E.A., Schulte-Hostede, S., and Kettrup, A., Alternatives for the determination of the soil adsorption coefficient, K, of non-ionic organic compounds — a review, Chemo-... 

Ionic organic compounds are often water soluble while the unionized forms will be less water soluble. Because of this, ion suppression is commonly used to enhance the separation of organic acids. A typical example of the use of ion suppression is for the separation of phenolic acids shown in Figure 5-19. Without the addition of acetic acid to the eluent the acids would have eluted as broadly tailed peaks with little retention. 

Wang et al. [607] studied the adsorption of dissolved organics from industrial effluents onto a commercial activated carbon. As illustrated in Table 20, they place emphasis on the pK, pK, or isoelectric point of the adsorbate and state that the pH effect upon the effectiveness of carbon adsorption mainly depends upon the nature of the adsorbed substance. Based on their own work and analysis of the literature, they postulate that maximum adsorption of organic acids and bases occurs around their respective pK , or pKh value, even though they acknowledge, at least as the ionic organic compounds become more complex, that electrostatic adsorption forces between the adsorbent and the ionic adsorbate appear to govern. ... 

The vesicle bilayer acts as a barrier of medium strength for water-soluble, non-ionic organic compounds. Sucrose solutions, for example, were applied as contrast agents in the light microscopy of stearic acid vesicles ". It took hours for the carbohydrate to penetrate this barrier. Efflux rates of radioactive sucrose were measured in cationic vesicles in the presence of different counterions. For this purpose, external sucrose was removed by ultrafiltration through Nucleopore polycarbonate with 0.4, 0.2 and 0.1 xm pores. The efflux rates were then determined by dialysis methods. In the case of dihexadecyldimethyl-... 

The possibility of complexation of inorganic salts, as well as of ionic and non-ionic organic compounds, can be explained by the dipole effect of the C-O bond in the polyether ring. Other hetero atoms such as nitrogen or sulfur may also act as donor atoms. The selective complexation of a specific cation, which is always associated with an anion because of electroneutrality, depends on the number and position of the hetero atoms. 

Roy, K., Sanyal, 1. and Roy, P.P. (2006) QSPR of the bioconcentration factors of non-ionic organic compounds in fish using extended topochemical atom (ETA) indices. SAR s[ QSAR Environ. Res., 17, 563-582. 

The Swelling Properties of Soil Organic Matter and Their Relation to Sorption of Non-Ionic Organic Compounds... 

Practical aspects. Most of the common anions and alkali/alkaline earth metal cations as well as NH/ can be detected directly. The same is possible for C, and C2 acids and other ionic organic compounds. 

Determination of uronic acids in the free dissolved fraction of seawater poses several difficulties, not least the low expected levels (<0.02 pmole 1" Mopper, 1977) and difficulties in removing inorganic salts from per se ionic organic compounds. 

P. Mukerjee, Use of Ionic Dyes in the Analysis of Ionic Surfactants and Other Ionic Organic Compounds, Analyt. Chem. 28, 870-873 (1956). 

Data on sorption of organic chemicals on dry and partially hydrated soils and of ionic organic compounds from water are limited. Consequently, the present discussion will emphasize the soil sorption of nonionic organic compounds from water. Moreover, the characteristic behavior of nonionic organic chemicals between soil and water is directly applicable in interpreting the fate of the majority of pesticides and industrial pollutants in aquatic systems. 

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