• Title, Summary, Keyword: partition coefficient

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The Transport Phenomena of Some Solutes through the Copolymer Membranes of 2-hydroxyethylmethacrylate (HEMA) with Selected Hydrophobic Monomers

  • Kim, Whan-Gun;Jhon, Mu-Shik
    • Bulletin of the Korean Chemical Society
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    • v.6 no.3
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    • pp.128-131
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    • 1985
  • A series of copolymer membranes of 2-hydroxyethylmethacrylate (HEMA) with selected hydrophobic monomers were prepared without crosslinking agents. The equilibrium water content, the partition coefficient, and the permeability of the solutes such as urea, methylurea, 1,3-di-methylurea, and acetamide via these membranes were measured. The partition coefficient data show that as the hydrophobicity of solutes increased, the partition of solutes were dictated by hydrophobic interaction between solute and polymer matrix. Diffusion coefficients obtained in these experiments decrease as the water content of polymer membrane decreases. This decrease is blunt as the excess heat capacities, ${\phi}C^0_p$ (excess) in aqueous solution at infinite dilution of solute increases. To investigate the relationship between water content and diffusion coefficient, the results of the diffusion experiments were examined in light of a free-volume model of diffusive transport. The remarkable increase of urea mobility in the polymer network containing relatively larger bulk water can be considered as water structure breaking effect.

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Feasibility of Fibrous Solid Phase Extraction to Alkylphenols Analysis (섬유상 고상 추출물질을 이용한 알킬페놀 화합물 분석 가능성)

  • Jung, Yong Jun
    • 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.

Large-Scale Purification of Protease Produced by Bacillus sp. from Meju by Consecutive Polyethylene Glycol/Potassium Phosphate Buffer Aqueous Two-Phase System

  • Cho, Seong-Jun;Kim, Chan-Hwa;Yim, Moo-Hyun;Lee, Cherl-Ho
    • 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.

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Distribution between Air-Soil Concentration of Organochlorine Pesticides (유기염소계 살충제의 대기-토양간 분배)

  • Choi, Min-Kyu;Chun, Man-Young
    • Environmental 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.

Protein Partition in an Aqueous Poly (ethyleneglycol)-salt Two-phase System (Poly(ethyleneglycol)과 인산염용액이 형성하는 2상계에서의 단백질 분획에 관한 연구)

  • Lee, Sam-Pin;Lee, Cherl-Ho
    • 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.

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Determination of Short-term Bioconcentration Factor and Partition Coefficient on Chlorothalonil in Carassius auratus(goldfish) (Carassius auratus(goldfish)를 이용한 Chlorothalonil의 단기간 생물농축계수와 분배계수의 측정)

  • 차춘근;전봉식;민경진
    • Journal of Environmental Health Sciences
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    • v.21 no.3
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    • pp.38-47
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    • 1995
  • The Bioconcentration factor (BCF) is used as an important criterion in the risk assessment of environmental contaminants. Also it can be used as indicator of biomagnification of environmentally hazardous chemicals through food-chain as well as a tool for ranking the bioconcentration potential of the chemicals in the environment. This paper reports the measured BCF value on Chlorothalonil in Carassius auratus(goldfish), under steady state, and examined correlation between the BCF value and the partition coefficient or acute toxicity or physicochemical properties. Carassius auratus(goldfish) was chosen as test organism and test period were 3-day, 5-day. Experimental concentrations were 0.005, 0.01 and 0.05 ppm. Chlorothalonil in fish tissue and in test water were extracted with n-hexane and acetonitrile. GC-ECD was used to detecting and quantitating of Chlorothalonil. Partition coefficient was determined by stir-flask method. $LC_{50}$ was determined on Chlorothalonil. Carbaryl and BPMC. The obtained results were as follows. 1. It was possible to determine short term BCFs of Chlorothalonil through relatively simple procedure in environmental concentrations. 2. $BF_3$ of Chlorothalonil in concentration of 0.005, 0.01 and 0.05 ppm were 2.1866$\pm$0.23446, 3.5269$\pm$0.23517, 10.2045$\pm$0.18053 and BCFs were 6.6543$\pm$0.55257, 6.9774$\pm$0.02500, 23.4576$\pm$2.06884, respectively. 3. Chlorothalonil concentration in fish extract and BCFs of Chlorothalonil were increased as increasing test concentration and prolonging test period. 4. Fate of test-water concentration on Chlorothalonil was greater than that of control-water con-centration. It is considered that greater fate of test-water concentration on Chlorothalonil is due to hydrolyzing nitrile group under the mild condition and substituting chloro group by some aromatic compounds in test water. 5. Determined logP of Chlorothalonil was 2.80. And determined $LC_{50}$ of Chlorothalonil in time of 24, 48, 72 and 96 hr were 0.1684, 0.1402, 0.1400, 0.1352(mg/l) respectively. And $LC_{50}$ of Carbaryl in above times were 19.918, 18.635, 18.466, 18.12(mg/l) respectively. $LC_{50}$ of BPMC were 10.248, 9.166, 9.087, 8.921(mg/l) respectively. 6. It is suggested that the BCF of Carbamates depend on partition coefficients. But BCF of Chlorothalonil, organochlorine pesticide, would be strongly influenced by steric, electronic effect of substituents than partition coefficient.

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A Study on the Partition Coefficients for Sulfur Compounds Related Composition of LPG (LPG 조성에 따른 황화합물의 분배계수에 관한 연구)

  • Kim, Yeong Gu
    • Journal of the Korean Chemical Society
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    • v.46 no.6
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    • pp.523-527
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    • 2002
  • Partition coefficient related composition of LPG are studied. Analysed sulfur compounds are ethyl mer-captan,n-propyl mercaptan and n-butyl mercaptan. The composition of liquid phase and gas phase in LPG are deter-mined by gas chromatography. The partition coefficient to related the boiling point of sulfur compounds, the temperature and the compositions of solvents, determined by using MLR(multiple linear regression) of SAS is follows; Kpc= $0.61222({\pm}0.6578)-0.04670({\pm}0.000959)Bp+0.26984(\pm0.06504)C4+0.003803(^{\circ}ae0.0019993)Tk,$ N=24, F=14.851, $R^2_{adj}$=0.6437. The boiling points of sulfur compounds at atmospheric pressure and the compositions of LPG effect mostly on partition coefficients. It is presumed that the gas odor elevating effects should be increased, where being on high tem-perature and larger amounts of n-butane.

Slow-Stirring Methods for Determining the n-Octanol/Water Partition Coefficient(Pow) of Highly Hydrophobic Chemicals (극소수성 물질들에 대한 Slow-Stirring방법에 의한 옥탄올/물 분배계수 측정)

  • Chang Hee Ra;Lee Bong Jae;Kim Kyun;Kim Yong Hwa
    • Environmental health and toxicology
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    • v.20 no.4
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    • pp.351-358
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    • 2005
  • The n -octanol/water partition coefficient (Pow) is one of the most important parameters employed for estimating a chemiral's environmental fate and toxicity. The shake-flask method, one direct experimental method, i.1 prone to experimental artifacts for highly hydrophobic compounds. Thus, a valid method for direct determination of the Pow of highly hydrophobic compounds is needed. The slow -stirring method has been demonstrated to provide reliable log Pow data to log Pow greater than 5. This study was performed to evaluate the accuracy of slow- stirring experiment for determination of log Pow, particularly for highly hydrophobic compounds. 1, 2, 3, 4-tetrachlorobenzene, hexachlorobezene, 2, 2', 3, 3', 5, 5', 6, 6'-octachlorobiphenyl, decachlorobiphenyl, and p, p'-DDT (4.5$\times$0.02, 5.41$\times$0.06, 7.26$\times$0.04, 7.87$\times$0.10, and 6.03$\times$0.06, respectively. The octanol/water partition coefficient by the slow-stirring method were very similar to the literature values. These results indicate that the slow- stirring method allows for reliable determination of log Pow of highly hydrophobic chemicals.