• Title, Summary, Keyword: partition coefficient

Search Result 275, Processing Time 0.044 seconds

Applicability of the HPLC Method for the Estimation of Octanol/water Partition Coefficient to Pesticides of Domestic Use (국내 사용 농약을 대상으로 한 HPLC 방법에 의한 옥탄올/물 분배계수 추정법의 적용성 검토)

  • Kim, Kyun;Kwon, Jin-Wook;Kim, Yong-Hwa
    • Environmental health and toxicology
    • /
    • v.16 no.4
    • /
    • pp.189-196
    • /
    • 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.

  • PDF

Diffusion of Progesterone in Polyacrylamide Gel (Polyacrylamide gel에서 Progesterone의 확산 거동)

  • 김명희;김말남;민병례
    • Korean Journal of Microbiology
    • /
    • v.28 no.3
    • /
    • pp.278-282
    • /
    • 1990
  • Diffusion and partition of progesterone into the polyacrylamide gel was examined. Diffusion coefficient of progesterone decreased down to an asymptotic value as the concentration of the organic solvents in the diffusing medium increased. However the partition coefficient diminished steadily. Crosslinking density in the gel didn't affected the diffusion coefficient considerably but lowered the partition coefficient due to the contraction of pore volume of the gel. Progesterone showed higher diffusion coefficient as well as partition coefficient in the polyurethane than in the polyacrylamide gel, which seems to be ascribed to the difference in hydrophobicity, pore volume and pore size of the polymer matrix.

  • PDF

Determination and Temperature Dependence of n-Octanol/Water Partition Coefficients for Seven Sulfonamides from (298.15 to 333.15) K

  • Congliang, Zhang;Yan, Wang;Fuan, Wang
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.7
    • /
    • pp.1183-1186
    • /
    • 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.

Organic Pollutant Transport in Unsaturated Porous Media by Atmospheric Breathing Processes( I ) - Partition Coefficient -

  • Ja-Kong;Lim, Jae-Shin;Do, Nam-Young
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • /
    • pp.50-53
    • /
    • 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.

  • PDF

Partition Coefficient of Proteins of Different Surface Hydrophobicity in Poly (ethylene glycol)-Dextran Aqueous Two Phase System (Poly(ethylene glycol)-Dextran 수용액 2상계에서 단백질들의 소수성에 따른 분획계수)

  • Lee, Sam-Pin;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
    • /
    • v.19 no.2
    • /
    • pp.140-145
    • /
    • 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.

  • PDF

BTEX와 액상간 분배성 알코올류 추적자의 분배특성 연구

  • Lee Seong-Su;Ju Sang-Yeon;Park Jun-Beom
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • /
    • pp.115-118
    • /
    • 2006
  • The partitioning tracer method has been studied as an alternative method for characterizing aquifers contaminated by nonaqueous phase liquids (NAPLs). Accurate partition coefficients of tracers partitioning between NAPL and water are needed to improve the reliability of the partitioning tracer method. In this research, partition coefficients of alcohol tracers partitioning between benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds and water are estimated from using the approach of equivalent alkane carbon number (EACN). General agreement was observed in between the measured and estimated partition coefficients. Based on these results we can verify that the EACN approach is suitable for estimating the partition coefficient.

  • PDF

Cadmium Adsorption and Exchangeable Cations Desorption in Soils: Effects of pH and Organic Matter Content (토양에서 카드뮴의 흡착과 치환성양이온의 탈착 : pH와 유기물함량의 영향)

  • 박병윤;신현무
    • Journal of Environmental Science International
    • /
    • v.5 no.2
    • /
    • pp.243-252
    • /
    • 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.

  • PDF

Nalidixic Acid Prodrugs: Amides from amino acid ester and nalidixic acid

  • Taori, Ashish;Nema, Rajesh;Kohli, D.V.;Uppadhyay, R.K.
    • Archives of Pharmacal Research
    • /
    • v.14 no.1
    • /
    • pp.48-51
    • /
    • 1991
  • Amides from amino acid ester and nalidixic acid were synthesized. The solubility characteristics and partition coefficient of the compounds were studied. The hydrolysis of the compounds was studied in the simulated gastric fluid and simulated intestinal fluid. Some compounds showed better antibacterial activity than nalidixic acid.

  • PDF

A study on the effects of intake port eccentricity and a partition between the two intake ports on the in-cylinder swirl characteristics in a valve diesel engine (4밸브 디젤기관의 흡기포트 편심과 두 흡기포트 사이의 격막이 실린더 내 선회 특성에 미치는 영향에 관한 연구)

  • Lee, Ji-Geun;Gang, Sin-Jae;No, Byeong-Jun
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.21 no.7
    • /
    • pp.948-961
    • /
    • 1997
  • The effects of intake port eccentricity and a partition between the two intake ports on the incylinder swirl characteristics in a 4 valve diesel engine having the two intake ports, one is a helical intake port and the other is a tangential intake port, were investigated by using the impulse swirl meter(ISM) in a steady flow test rig. Mean flow coefficient ( $C_{f(mean)}$, swirl ratio ( $R_{s}$) and the mass flowrate through the two intake ports with and without intake port partition were measured. The results showed that the characteristics of in-cylinder swirl ratio formed by a 4-valve cylinder head were largely affected by valve eccentricity ratio ( $N_{y}$) and the existence of an intake port partition between the two intake ports. Mean flow coefficient ( $C_{f(mean)}$) increases and swirl ratio ( $R_{s}$) decreases in case of being the partition between the two intake ports. And also the mass flowrate through the tangential intake port is 19.0% and 7.7% more than that of the helical intake port in case of the two intake ports with and without partition respectively.ively.

불포화 토양내 유류성분의 포화도 평가를 위한 분배추적자의 활용 방안

  • Park Gi-Ho;Park Min-Ho;Sin Hang-Sik;Go Seok-O
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • /
    • pp.20-28
    • /
    • 2006
  • Partitioning tracer tests were conducted to quantify the saturation degree of diesel and water in unsaturated soil, respectively. The use of partitioning tracers that partition into diesel, water, and air (i.e., three-phase partitioning), is in attractive alternative to traditional coring and analysis method. These gaseous partition tracers not global warming gas like CFC's are Butane, Acetylene, Ethylene, Methylene chloride, and Methane. The glass column packed with sandy soil was prepared, in which a three-phase system of air, water, and diesel was maintained. Conservative and partition gas tracers were injected into the columns and detected easily using a single GC detector(FID). For each tracer, a method of moments was used to estimate partition coefficient between water, diesel. and the air, respectively. The results from the column studies showed that the diesel/air tracer partition coefficient ranged from 8.2 to 868 and 9.2 for water/air. Saturation degree of diesel and water in the column, predicted by the partition coefficients obtained from tests, was underestimated up to 66% and 23% respectively.

  • PDF