Determination of n-octanol/water partition coefficients of tetrachlorobenzyltoluenes individually and in a mixture by the slow stirring method

Haelst, A.G. van; Heesen, P.F.; Wielen, F.W.M. van der; Govers, H.A.J.

doi:10.1016/0045-6535(94)90312-3

Cited by 20 publications

(9 citation statements)

References 29 publications

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“…The slow‐stirring method [6–10] has been shown to be applicable for the determination of K ow values of very hydrophobic compounds. Slow‐stirring prevents the formation of a microemulsion of octanol in the water phase.…”

Section: Introductionmentioning

confidence: 99%

Physicochemical properties of polycyclic aromatic hydrocarbons: Aqueous solubilities, n‐octanol/water partition coefficients, and Henry's law constants

Maagd

Hulscher

Heuvel

et al. 1998

Enviro Toxic and Chemistry

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Aqueous solubilities, n-octanol/water partition coefficients (K ow s), and Henry's law constants were determined for a range of polycyclic aromatic hydrocarbons (PAHs) using a generator-column, slow-stirring, and gas-purge method, respectively. The currently obtained data were compared to available literature data. For seven of the PAHs no K ow s previously were determined with the slow-stirring method. For four of the PAHs the present study reports the first experimental Henry's law constants. Relationships between subcooled liquid solubilities, K ow s, and Henry's law constants as a function of molar volume are discussed. A consistent data set was obtained, for which an excellent correlation was found between subcooled liquid solubility and molar volume. A linear fit did not accurately describe the relationship between log K ow and molar volume. This is probably due to a decreasing solubility in n-octanol with increasing molar volume. Finally, a high correlation was found between Henry's law constant and molar volume. The presently obtained dataset can be used to predict the fate and behavior of unsubstituted homocyclic PAHs.

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Section: Introductionmentioning

confidence: 99%

Physicochemical properties of polycyclic aromatic hydrocarbons: Aqueous solubilities, n‐octanol/water partition coefficients, and Henry's law constants

Maagd

Hulscher

Heuvel

et al. 1998

Enviro Toxic and Chemistry

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“…This method is an adaption of the slow-stir technique initially developed to determine the octanol-water partition coefficients (K ow ) of hydrophobic organic chemicals [15] and has been applied by a number of researchers to measure K ow . [16][17][18][19]. The slow-stir method for K ow determination is recognized as an OECD test guideline [20].…”

Section: Introductionmentioning

confidence: 99%

Inter-laboratory comparison of water solubility methods applied to difficult-to-test substances

et al. 2021

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Water solubility is perhaps the single most important physical–chemical property determining the environmental fate and effects of organic compounds. Its determination is particularly challenging for compounds with extremely low solubility, frequently referred to as “difficult-to-test” substances and having solubility’s generally less than 0.1 mg/L. The existing regulatory water solubility test for these compounds is the column elution method. Its applicability, however, is limited, to non-volatile solid or crystalline hydrophobic organic compounds. There currently exists no test guideline for measuring the water solubility of very hydrophobic liquid, and potentially volatile, difficult-to-test compounds. This paper describes a “slow-stir” water solubility methodology along with results of a ring trial across five laboratories evaluating the method’s performance. The slow-stir method was applied to n-hexylcyclohexane, a volatile, liquid hydrophobic hydrocarbon. In order to benchmark the inter-laboratory variability associated with the proposed slow-stir method, the five laboratories separately determined the solubility of dodecahydrotriphenylene, a hydrophobic solid compound using the existing column elution guideline. Results across the participating laboratories indicated comparable reproducibility with relative standard deviations (RSD) of 20% or less reported for each test compound – solubility method pair. The inter-laboratory RSD was 16% for n-hexylcyclohexane (mean 14 µg/L, n = 5) using the slow-stir method. For dodecahydrotriphenylene, the inter-laboratory RSD was 20% (mean 2.6 µg/L, n = 4) using the existing column elution method. This study outlines approaches that should be followed and the experimental parameters that have been deemed important for an expanded ring trial of the slow-stir water solubility method.

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“…Among them are the dialysis bag experiment [16], the generator column experiment with an octanol phase on a solid support [17,18] or bulk liquid phase [19], and the slow-stirring experiment. The latter, introduced by Brooke et al [20] and subsequently applied successfully in determining the log P ow of highly hydrophobic chemicals, such as polychlorinated biphenyls (PCBs) and chlorinated pesticides, higher n-alkanes, chlorinated alkanes, and polycyclic aromatic hydrocarbons [14,[20][21][22][23][24][25][26][27], avoids formation of microscopic octanol droplets in the water phase. As a consequence, overestimation of C w,i because of test-compound molecules associated to such droplets does not occur, and precise and accurate determination of the P ow of compounds with log P ow of as high as 8.2 is possible [14].…”

Section: Introductionmentioning

confidence: 99%

SLOW-STIRRING METHOD FOR DETERMINING THE n-OCTANOL/WATER PARTITION COEFFICIENT (Pow) FOR HIGHLY HYDROPHOBIC CHEMICALS: PERFORMANCE EVALUATION IN A RING TEST

Tolls¹,

Bodo²,

Felip³

et al. 2003

Environ Toxicol Chem

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The n-octanol/water partition coefficient (Pow) is one of the most important parameters employed for estimating a chemical's environmental fate and toxicity. The currently adopted test guidelines for its determination do not allow for reliable determination of log Pow greater than 5. The slow-stirring experiment, in contrast, has been demonstrated to provide reliable log Pow data up to log Pow of 8.3. To validate this method and to obtain its approval as an official Organization for Economic Cooperation and Development (Paris, France) test guideline, a ring test was performed to evaluate the accuracy and precision of the slow-stirring experiment for determination of log Pow, particularly for highly hydrophobic compounds. Up to 15 volunteer laboratories tested 1,2,3,4-tetrachlorobenzene, hexachlorobenzene. 2,2',3,3',5,5',6,6'-octachlorobiphenyl, and decachlorobiphenyl (4.5 < log Pow < 8.2). The ring-test results for the respective chemicals were 4.62, 5.50, 7.39, and 8.18. The results deviated by less than 0.1 log Pow units from the reference log Pow. In addition, the relative standard deviations of log Pow were less than 2%. Using the protocol of the ring test, log Pow of p,p'-DDT was determined to be 6.24 +/- 0.05 (mean +/- standard deviation). In combination, these results indicate that the slow-stirring method is precise and accurate and, thus, allows for reliable determination of log Pow of highly hydrophobic chemicals.

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Determination of n-octanol/water partition coefficients of tetrachlorobenzyltoluenes individually and in a mixture by the slow stirring method

Cited by 20 publications

References 29 publications

Physicochemical properties of polycyclic aromatic hydrocarbons: Aqueous solubilities, n‐octanol/water partition coefficients, and Henry's law constants

Physicochemical properties of polycyclic aromatic hydrocarbons: Aqueous solubilities, n‐octanol/water partition coefficients, and Henry's law constants

Inter-laboratory comparison of water solubility methods applied to difficult-to-test substances

SLOW-STIRRING METHOD FOR DETERMINING THE n-OCTANOL/WATER PARTITION COEFFICIENT (Pow) FOR HIGHLY HYDROPHOBIC CHEMICALS: PERFORMANCE EVALUATION IN A RING TEST

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