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1035727 
Journal Article 
Distribution of neutral organic compounds between n-heptane and methanol or N,N-dimethylformamide 
Ahmed, H; Poole, CF 
2006 
Yes 
Journal of Separation Science
ISSN: 1615-9306
EISSN: 1615-9314 
29 
14 
2158-2165 
English 
17069245 
WOS:000240891500006 
Partition coefficients for a number of varied compounds were determined for the n-heptane-methanol and n-heptane-DMF partition systems and used to derive a general model for the distribution of neutral compounds in the biphasic systems. The partition coefficient, log Kp, was correlated through the solvation parameter model giving log Kp = -0.056 + 0.164E-0.620S-1.337A-0.957B + 0.507V for the n-heptane-methanol system with a multiple correlation coefficient of 0.986, standard error of the estimate 0.086, and Fischer statistic 413 for 65 compounds. For n-heptane-DMF, the model is log Kp = 0.065 + 0.030E-1.405S-2.039A-0.806B + 0.721V with a multiple correlation coefficient of 0.991, standard error of the estimate 0.080, and Fischer statistic 560 for 59 compounds. In the models the solute descriptors are excess molar refraction E, dipolarity/polarizability S, overall hydrogen bond acidity, and basicity A and B, respectively, and McGowan's characteristic volume V. Either model is expected to be able to estimate further values of the partition coefficient to about 0.08 log units and is applicable to a wide range of compounds. Applications include the choice of partitioning systems for sample clean-up, countercurrent chromatography, and estimation of solute descriptors for water insoluble or unstable compounds. 
N,N-dimethylformamide; n-heptane; methanol partitioning; solvation parameter model 
• Methanol (Non-Cancer)
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