Solubility organic compounds in water

Gross, P.M., Saylor, J.H. (1931) The solubilities of certain slightly soluble organic compounds in water. J. Am. Chem. Soc. 53, 1744-1751. 

Thermodynamically, the electrochemical mineralization (EM) of any soluble organic compound in water should be achieved at low potentials, widely before the thermodynamic potential of water oxidation to molecular oxygen (1.23 V/SHE under standard conditions) as it is given by (1.1) ... 

Dissolved organic carbon (DOC) 1) Carbon contained in colloidal (<10/iim) organic particles and in soluble organic compounds in water. 2) Organic molecules representing decay products of vegetation that pass through a 0.45 /rm filter. 

Divide the saturated solution of n-butyl alcohol in water into three approximately equal parts. Treat these respectively with about 2-5 g. of sodium chloride, potassium carbonate and sodium hydroxide, and shake each until the soli have dissolved. Observe the effect of these compounds upon the solubility of n-butanol in water. These results illustrate the phenomenon of salting out of organic compounds, t.e., the decrease of solubility of organic compounds in water when the solution is saturated with an inorganic compound. The alcohol layer which separates is actually a saturated solution of water in n-butyl alcohol. 

Metal ions in aqueous solution exist as complexes with water. The solubility of organic compounds in water depends primarily on their polarity and their ability to form hydrogen bonds with water. Organic compounds with a large part of polar components such as acetic acid, dissolve in water without limit. In such cases, the polar part dominates. By contrast, soaps and detergents have a polar end attached to a relatively large nonpolar part of the molecule. They have limited solubility and the molecules tend to coalesce to form micelles. 

Since the publication of the third edition, additional data have been critically reviewed. New or additional data included in this edition are bioconcentration factors, aquatic mammalian toxicity values, degradation rates, corresponding half-lives in various environmental compartments, ionization potentials, aqueous solubility of miscellaneous compounds, Henry s law constants, biological, chemical, and theoretical oxygen demand values for various organic compounds. Five additional tables have been added Test Method Number Index, Dielectric Values of Earth Materials and Fluids, Lowest Odor Threshold Concentrations of Organic Compoimds in Water, and Lowest Threshold Concentrations of Organic Compounds in Water. 

Lyubartsev, A.P., Jacobsson, S.P., Sundholm, G and Laaksonen, A. Solubility of organic compounds in water/octanol systems. An expanded ensemble molecular dynamics simulation study of log Pparameters, J. Phys. Chem. B, 105(32) 7775-7782, 2001. 

Simoneit BRT, Elias VO, Kobayashi M, Kawamura K, Rushdi AI, Medeiros PM, Rogge WE Didyk BM, Sugars — dominant water-soluble organic compounds in soils and characterization as tracers in atmospheric particulate matter. Environ Sci Technol 38 5939-5949, 2004. 

Graham B, Mayol-Bracero OL, Guyon P, Roberts GC, Decesari S, Facchini MG, Artaxo P, Maenhaut W, Koll P, Andreae MO, Water-soluble organic compounds in biomass burning aerosols over Amazonia. 1. Characterization... 

Figure 6.13 shows the concentrations of organic compounds in water that are sufficient to immobilize tadpoles, and their values of log P or the partition coefficient between octanol and water. Thymol, with a log P of 1000, is 10,000 times more toxic than ethanol, which has a log P of around 0.3. A plausible explanation of this phenomenon lies in the structure of the membranes of cells, which are made of two layers of lipid, or fat, so that a more fat-soluble substance would find it easier to penetrate the cell and to cause damage. 

Svec HJ, Fritz JS, Calder GV. 1974. Trace soluble organic compounds in potable water supplies. Report to U.S. Department of Interior, Office of Water Resources Research, by Iowa State University, Department of Chemistry, Ames, lA. NTIS No. PB-228523. 

However, it may also be possible that the buffer negatively influences the solubility of the drug and other excipients. Buffer salts can either increase or decrease the solubility of organic compounds in water. The effect depends on a combination of the polarity of the solute and of the salt. Nonpolar solutes are solubilized (salted in) by less polar organic salts and are desolubilized (salted out) by polar salts. Conversely, polar solutes are salted in by polar salts and salted out by organic salts. It was shown that for a semipolar solute such as ampicillin, strong electrolytes... 

When considering the solubility of a solid organic compound in water, conceptually we can imagine first converting it to the liquid state and then proceeding as above for a liquid compound. The free energy cost involved in the solid-to-liquid conversion is referred to as the free energy of fusion, (Chapter 4). This entity can be derived... 

Figure 5.6 Illustration of the effect of a completely water-miscible solvent (CMOS, i.e., methanol) on the activity coefficient of organic compounds in water-organic solvent mixtures decadic logarithm of the activity coefficient as a function of the volume fraction of methanol. Note that the data for naphthalene (Dickhut et al., 1989 Fan and Jafvert, 1997) and for the two PCBs (Li and Andren, 1994) have been derived from solubility measurements whereas for the anilins (Jayasinghe etal., 1992), air-water partition constants determined under dilute conditions have been used to calculate y,f.

Svec, H. J. Fritz, J. S. Calder, G. V. Trace Soluble Organic Compounds in Potable Water Completion Report, Project A-064-1A Department of Chemistry, Iowa State University, December 1973. 

A previous exploratory study attempted to recover the soluble, poorly volatile subclass of organic compounds in water (3). It used a set.of sequential adsorbents. Silica gel, the first adsorbent, filtered out particulate matter and adsorbed some hydrophobic compounds. The next adsorbent was a cation-exchange bed that recovered cations and amphoteric substances, and the last adsorbent was an anion-exchange bed. The effluent from this series of adsorbents contained the neutral compounds. The eluates from each bed and the effluents were then concentrated under vacuum. This system, the parfait method, was demonstrated to recover parts-per-billion concentrations of several known mutagens in amounts sufficient to be detected by bioassay. 

Solubilities of 1,3-butadiene and many other organic compounds in water have been extensively studied to gauge the impact of discharge of these materials into aquatic systems. Estimates have been advanced by using the UNIFAC derived method (19,20). Similarly, a mathematical model has been developed to calculate the vapor—liquid equilibrium (VLE) for 1,3-butadiene in the presence of steam (21). 

Two methods have been utilized to circumvent the low solubility of organic compounds in water. The first is use of emulsifying ngem.--. such aa common household detergents, from which the product ran bo separated readily by steam-distillation sw.yot.iss The second is use of a suitable mutual solvent, e.g. acetone,1 fort-butanol,741-777 or dioxan.80- i . m>, 4ei, ess. iocs. i 7s. i4 e, ims, ms.m ... 

An emulsifier is a molecule that possesses both polar and nonpolar moieties, i.e., it is amphiphilic. In very dilute water solutions, emulsifiers dissolve and exist as monomers, but when their concentration exceeds a certain minimum, the so-called critical micelle concentration (CMC), they associate spontaneously to form aggregates - micelles. Micelles are responsible for many of the processes such as enhancement of the solubility of organic compounds in water, catalysis of many reactions, alteration of reaction pathways, rates and equilibria, reaction loci for the production of polymers, etc. 

Research is ongoing to develop a "Master Analytical Scheme" for organic compounds in water (Michael et al. 1988), which includes chlorobenzene as an analyte. The overall goal is to detect and. quantitatively measure organic compounds at 0.1 pg/L in drinking water, 1 pg/L in surface waters, and 10 pig/L in effluent waters. Analytes are to include numerous semivolatile compounds and some compounds that are only "semi-soluble" in water, as well as volatile compounds (bp < 150°C). 

However, not every aerosol particle serves as CCN. Accumulation mode aerosols provide the nuclei for most cloud drops (Penner et al., 2001). As in the case of anthropogenic and natural sulphate particles, OAs can also serve as CCN (Ramanathan et al., 2001). Additionally, the presence of water-soluble organic compounds in the particles and the presence of soluble gases (HN03) in the atmosphere can amplify the CCN activity of the aerosols and further increase the concentration of cloud droplets and the indirect forcing (Charlson et al., 2001). Also, biomass... 

Cappiello, A., Simoni, E., Fiorucci, C., Mangani,F., Palma, P.,Trufelli, H., Decesari, S., Facchini, M. C., and Fuzzi, S. (2003). Molecular characterization of the water-soluble organic compounds in fogwater by ESIMS/MS. Environ. Sci. Technol. 37,1229-1240. 

Chan, M. N., Choi, M. Y., Ng, N. L., and Chan, C. K. (2005). Hygroscopicity of water-soluble organic compounds in atmospheric aerosols Amino acids and biomass burning derived organic species. Environ. Sci. Technol. 39,1555-1562. 

Decesari, S., Facchini, M. C., Matta, E., Lettini, F., Mircea, M., Fuzzi, S., Tagliavini, E., and Putaud, J.-P. (2001). Chemical features and seasonal variation of fine aerosol water-soluble organic compounds in the Po Valley, Italy. Atmos. Environ. 35, 3691-3699. 

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