• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1183-1186
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• 2007

A shake-flask method was used to determine the n-octanol/water partition coefficients of sulfamethazine, sulfadimethoxine, sulfamethoxydiazine, sulfamonomethoxine, sulfamethoxazole, sulfaquinoxaline and sulfachloropyrazine from (298.15 to 333.15) K. The results showed that the n-octanol/water partition coefficient of each sulfonamide decreased with the increase of temperature. Based on the fluid phase equilibrium theory, the thermodynamic relationship of n-octanol/water partition coefficient depending on the temperature is proposed, and the changes of enthalpy, entropy, and the Gibbs free energy function for sulfonamides partitioning in n-octanol/ water are determined, respectively. Sulfonamides molecules partitioning in n-octanol/water is mainly an enthalpy driving process, during which the order degrees of system increased. The temperature effect coefficient of n-octanol/water partition coefficient is discussed. The results show that its magnitude is the same as that of values in the literature.

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.189-196
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• 2001

Octanol/water partition coefficients of 52 chemicals were calculated using RP-HPLC estimation method and predicted by computer program, PCHEM. The result showed relationship between literature values and RP-HPLC observed values (relative coefficient r$^2$＝0.916), but the relationship of PCHEM values with literature values was lower than RP-HPLC value (relative coefficient r$^2$＝0.795). The average difference in partition coefficient between the RP-HPLC method and flask-shaking method was log Kow＝0.54, while the average difference between the values predicted form the computer program and flask- shaking method was log Kow = 0.36 Compared to octanol/water partition coefficients by 3 methods (Flask-shaking, RP-HPLC, computer prediction), the octanol/water partition coefficient values based on the flask-shaking method were very similar to the literature values, while the octanol/water partition coefficient values by RP-HPLC method without to consider the dead time, and computer prediction values did not significantly differ with the literature values.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.11a
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• pp.50-53
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• 1996

This paper reports the experimental results for the determination of the overall partition coefficient of VOCs in unsaturated soil, A chromatographic method was used for the determination of gaseous partition coefficients to natural soil under various water content conditions. The equilibrium vapor pressure of water over saturated salt solution was used to fix the relative humidity of the air and control the water content of the soil systems. The transport behavior was studied for dichloromethane, trichloroethane and dichlorobenzene pollutants, with log octanol-water partition coefficients(log $K_{ow}$ ) which range from 1.25 to 3.39, or water to soil partitioning which varies by 135 times; water solubility constants which vary by 3 times; and vapor pressures which range from 1 to 362 torr. Water content of the soil had a pronounced effect on the effective partition coefficient(between gas and soil + water stationary phase) as well as on the effective dispersion coefficient.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.140-145
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• 1987

The partition coefficient of the proteins of known effective hydrophobicity was determined in a poly (ethylene glycol)-dextran aqueous two-phase system. The changes in the partition coefficient was also determined when a fraction of PEG-palmitate (PEG-P) was added to the system. The partition coefficient of the proteins increased as the concentrations of PEG and dextran increased at a constant phase volume ration irrespective of the effective hydrophobicity of the proteins. When small amounts of PEG-P were added to the PEG phase, the partition coefficients of BSA and ${\beta}-lactoglobulin$, which had relative hydrophobicity (RI) of 700 and 120, respectively, increased more than ten-fold, whereas ovalbumin whose RI was 5 showed little change. The drastic increases m the partition coefficient were observed by the addition of PEG-P in 2% level to the PEG system. Addition of PEG-P over 5% level resulted in a slight further increase in the partition coefficient of all proteins tested.

• Environmental Analysis Health and Toxicology
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• v.22 no.4
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• pp.299-304
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• 2007

This paper was studied to investigate the equilibrium state between organochlorine pesticides (OCPs) concentration of air and soil, and to know whether soil is a secondary pollution source of OCPs in air or not. The OCPs concentration of air ($C_{air}$) and soil ($C_{soil}$) is not related to molecular weight, vapor pressure ($P_L$) and octanol-air partition coefficient ($K_{oa}$). The slope of the regression line between soil-air partition coefficient ($K_{sa}$) and scavenging coefficient ($C_{soil}/C_{air}$) was 0.2952, which the OCPs concentration between air and soil did not reached to the equilibrium state. The soil/air fugacity quotients ($f_{soil}/f_{air}$) of p, p'-DDT/DDD/DDE and ${\beta}-HCH\;(0.30{\sim}0.67$), which is smaller than 1, means the deposit of OCPs from air to soil. However, $f_{soil}/f_{air}$ of heptachlor, heptachlor epoxide, ${\alpha}/{\gamma}-chlordane$, trans-nonachlor, endosulfan sulfate and ${\alpha}/{\gamma}-HCH\;(1.90{\sim}73.25)$, which is greater than 1, means that soil is secondary pollution source of OCPs in air.

• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.498-503
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• 1999

Protease produced from Bacillus sp. FSE-68 was isolated from Meju, a Korean fermented soybean starter, and was purified by a two-consecutive aqueous two-phase system. The change of partition coefficient (K) in the polyethylene glycol (PEG)/potassium phosphate buffer (PPB) aqueous two-phase system was measured at different pHs (6.0- 9.2), PPB concentrations (8-12%), and temperatures (4 and $20^{\circ}C$). As the PPB concentration in the aqueous two-phase system increased, the protease concentration in the top phase (PEG-rich phase) increased, thereby enhancing the partition coefficient. The minimum partition coefficient of the protease was achieved at pH 7.0, whereas that of the total protein was at pH 6.0. The biggest difference in partition coefficients of total protein and protease occurred at pH 6.0. It was interesting to note that the partition coefficient of protease decreased as the temperature increased. The optimum condition of the primary aqueous two-phase extraction of Bacillus sp. FSE-68 was pH 6.0, 14% (w/w) PPB, and 16% (w/w) PEG at $4^{\circ}C$, and the crude enzyme concentration in this system was 50% (w/w). The protease, which was concentrated in the top phase, was further mixed with 15% (w/w) PPB (pH 7.0) in the ratio of 1:1 at $20^{\circ}C$ to elute the bottom phase (PPB-rich phase). Using these steps, the purification fold achieved was 9.2 with a 44.7% yield.

• Journal of Korean Society on Water Environment
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• v.27 no.3
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• pp.329-333
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• 2011

p-phenylene-2,5-benzobisoxazole (PBO; Zylon$(R)$) fibers as an adsorbent were employed for solid phase extraction of aqueous alkylphenols. The removal ratios for 10 kinds of alkylphenols at initial concentration of $100{\mu}gL^{-1}$ were in the range of 16.8-96.3% and the removals increased with the increase of the phase ratio (fiber weight/solution volume). The plots of the logarithm of partition coefficient (log K) were correlated with the logarithm of the n-octanol/water partition coefficient (log P). The adsorbed alkylphenols were completely desorbed with the mixture of acetonitrile and dichloromethane.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1463-1464
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• 2011

• Journal of Environmental Science International
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• v.5 no.2
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• pp.243-252
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• 1996

In order to investigate the effects of pH and organic matter content on cadmium adsorption and exchangeable cations desorption in soils, the adsorption isotherms of cadmium and the desorption isotherms of calcium and magnesium on four New jersey soils at four pH values were plotted, and the cadmium partition coefficients (Kd) were also calculated. The slopes of cadmium adsorption isotherms dramatically increased with increasing solution pH. Judging from Langmuir adsorption equations, the maximum adsorption quantities(b) of cadmium at high pH values were much greater than those at low pH values for the same soil. The partition coefficients increased greatly with increasing solution pH. The slopes of regression equations between partition coefficients and pH values were steep in the order of the organic matter content of the soils. The correlation coefficients (r2) between partition coefficient and organic matter content for soils. The correlation coefficients (r2) between partition coefficient and organic matter content for $1\times10^{-4}$M increased from 0.3027 at pH 4.0 to 0.9964 at pH 8.5 and from 0.2093 at pH4.0 at 0.9657 at pH 8.5 for$2\times10^{-4}$M ${Cd(NO_3)}_2$. The desorption quantities of calcium and magnesium decreased with increasing solution pH and increased with- increasing cadmium adsorption.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.285-289
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• 1987

The partition behavior or proteins in an aqueous two-phase system of poly (ethyleneglycol)-potassium phosphate buffer (PEG/PPB) was investigated. The proteins of different surface hydrophobicity, i.e. Bovine serum albumin (BSA), ${\beta}-lactoglobulin$, ovalbumin. moved to the PPB-rich bottom phase in a PEG(12%)/PPB (12%) two-phase system resulting in very low partition coefficients. When the concentration of PPB increased to 15% level. the electric potential of bottom phase changed from +50 mV to zero and the partition coefficient tended to increase. The change In the molar ratio of $K_2HPO_4/KH_2PO_4$ in PPB from 1.43 to 9.55 caused the volume ratio of top to bottom phase $(V_t/V_b)$ to be decreased and protein partition coefficient increased. When the concentration of PPB was elevated from 14% to 26%, the $V_t/V_b$ decreased from 1.5 to 0.39 and the partition coefficient of proteins increased drastically; ${\beta}-lactoglobulin$ 74 fold. BSA 32 fold, ovalbumin 12 fold and lysozyme 5 fold.