Estimating n-octanol-water partition coefficients for neutral highly hydrophobic chemicals using measured n-butanol-water partition coefficients

Kaila B. Hanson; Dale J. Hoff; Tylor J. Lahren; David R. Mount; Anthony J. Squillace; Lawrence P. Burkhard

doi:10.1016/j.chemosphere.2018.11.141

Estimating n-octanol-water partition coefficients for neutral highly hydrophobic chemicals using measured n-butanol-water partition coefficients

Kaila B. Hanson, Dale J. Hoff, Tylor J. Lahren, David R. Mount, Anthony J. Squillace, Lawrence P. Burkhard

Research output: Contribution to journal › Article › peer-review

21 Scopus citations

Abstract

Direct measurement of the n-octanol partition coefficients (K_OW) for highly hydrophobic organic chemicals is extremely difficult because of the extremely low concentrations present in the water phase. n-Butanol/water partition coefficients (K_BW) are generally much lower than K_OW due to the increased solubility of solute in the alcohol saturated aqueous phase, and therefore become easier to measure. We measured the K_BW for 25 neutral organic chemicals having measured log K_OWs ranging from 2 to 9 and 4 additional highly hydrophobic chemicals, with unmeasured K_OWs, having estimated log K_OWs ranging from 6 to 18. The measured log K_BW and log K_OW values were linearly related, r² = 0.978, and using the regression developed from the data, K_OWs were predicted for the 4 highly hydrophobic chemicals with unmeasured K_OWs. The resulting predictions were orders of magnitude lower than those predicted by a variety of computational models and suggests the estimates of K_OW in the literature for highly hydrophobic chemicals (i.e., log K_OW greater than 10) are likely incorrect by several orders of magnitude.

Original language	English (US)
Pages (from-to)	616-623
Number of pages	8
Journal	Chemosphere
Volume	218
DOIs	https://doi.org/10.1016/j.chemosphere.2018.11.141
State	Published - Mar 2019
Externally published	Yes

Bibliographical note

Funding Information:
We thank David Tobias for his comments on an earlier draft of this manuscript. The information in this document has been funded wholly by the U.S. Environmental Protection Agency (US-EPA). This manuscript has been reviewed in accordance with the requirements of the US-EPA and approved for publication. Approval does not signify that the contents reflect the views of the Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.

Publisher Copyright:
© 2018

Keywords

Collander equation
n-Butanol/water partition coefficients
n-octanol/water partition coefficients (K)

Access

10.1016/j.chemosphere.2018.11.141

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442469

OpenUrl availability

Full text

Cite this

@article{d25be548e5284cceaa4ba1870a2d2caf,

title = "Estimating n-octanol-water partition coefficients for neutral highly hydrophobic chemicals using measured n-butanol-water partition coefficients",

abstract = "Direct measurement of the n-octanol partition coefficients (KOW) for highly hydrophobic organic chemicals is extremely difficult because of the extremely low concentrations present in the water phase. n-Butanol/water partition coefficients (KBW) are generally much lower than KOW due to the increased solubility of solute in the alcohol saturated aqueous phase, and therefore become easier to measure. We measured the KBW for 25 neutral organic chemicals having measured log KOWs ranging from 2 to 9 and 4 additional highly hydrophobic chemicals, with unmeasured KOWs, having estimated log KOWs ranging from 6 to 18. The measured log KBW and log KOW values were linearly related, r2 = 0.978, and using the regression developed from the data, KOWs were predicted for the 4 highly hydrophobic chemicals with unmeasured KOWs. The resulting predictions were orders of magnitude lower than those predicted by a variety of computational models and suggests the estimates of KOW in the literature for highly hydrophobic chemicals (i.e., log KOW greater than 10) are likely incorrect by several orders of magnitude.",

keywords = "Collander equation, n-Butanol/water partition coefficients, n-octanol/water partition coefficients (K)",

author = "Hanson, {Kaila B.} and Hoff, {Dale J.} and Lahren, {Tylor J.} and Mount, {David R.} and Squillace, {Anthony J.} and Burkhard, {Lawrence P.}",

note = "Funding Information: We thank David Tobias for his comments on an earlier draft of this manuscript. The information in this document has been funded wholly by the U.S. Environmental Protection Agency (US-EPA). This manuscript has been reviewed in accordance with the requirements of the US-EPA and approved for publication. Approval does not signify that the contents reflect the views of the Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Publisher Copyright: {\textcopyright} 2018",

year = "2019",

month = mar,

doi = "10.1016/j.chemosphere.2018.11.141",

language = "English (US)",

volume = "218",

pages = "616--623",

journal = "Chemosphere",

issn = "0045-6535",

publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Estimating n-octanol-water partition coefficients for neutral highly hydrophobic chemicals using measured n-butanol-water partition coefficients

AU - Hanson, Kaila B.

AU - Hoff, Dale J.

AU - Lahren, Tylor J.

AU - Mount, David R.

AU - Squillace, Anthony J.

AU - Burkhard, Lawrence P.

N1 - Funding Information: We thank David Tobias for his comments on an earlier draft of this manuscript. The information in this document has been funded wholly by the U.S. Environmental Protection Agency (US-EPA). This manuscript has been reviewed in accordance with the requirements of the US-EPA and approved for publication. Approval does not signify that the contents reflect the views of the Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Publisher Copyright: © 2018

PY - 2019/3

Y1 - 2019/3

N2 - Direct measurement of the n-octanol partition coefficients (KOW) for highly hydrophobic organic chemicals is extremely difficult because of the extremely low concentrations present in the water phase. n-Butanol/water partition coefficients (KBW) are generally much lower than KOW due to the increased solubility of solute in the alcohol saturated aqueous phase, and therefore become easier to measure. We measured the KBW for 25 neutral organic chemicals having measured log KOWs ranging from 2 to 9 and 4 additional highly hydrophobic chemicals, with unmeasured KOWs, having estimated log KOWs ranging from 6 to 18. The measured log KBW and log KOW values were linearly related, r2 = 0.978, and using the regression developed from the data, KOWs were predicted for the 4 highly hydrophobic chemicals with unmeasured KOWs. The resulting predictions were orders of magnitude lower than those predicted by a variety of computational models and suggests the estimates of KOW in the literature for highly hydrophobic chemicals (i.e., log KOW greater than 10) are likely incorrect by several orders of magnitude.

AB - Direct measurement of the n-octanol partition coefficients (KOW) for highly hydrophobic organic chemicals is extremely difficult because of the extremely low concentrations present in the water phase. n-Butanol/water partition coefficients (KBW) are generally much lower than KOW due to the increased solubility of solute in the alcohol saturated aqueous phase, and therefore become easier to measure. We measured the KBW for 25 neutral organic chemicals having measured log KOWs ranging from 2 to 9 and 4 additional highly hydrophobic chemicals, with unmeasured KOWs, having estimated log KOWs ranging from 6 to 18. The measured log KBW and log KOW values were linearly related, r2 = 0.978, and using the regression developed from the data, KOWs were predicted for the 4 highly hydrophobic chemicals with unmeasured KOWs. The resulting predictions were orders of magnitude lower than those predicted by a variety of computational models and suggests the estimates of KOW in the literature for highly hydrophobic chemicals (i.e., log KOW greater than 10) are likely incorrect by several orders of magnitude.

KW - Collander equation

KW - n-Butanol/water partition coefficients

KW - n-octanol/water partition coefficients (K)

UR - http://www.scopus.com/inward/record.url?scp=85059309649&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85059309649&partnerID=8YFLogxK

U2 - 10.1016/j.chemosphere.2018.11.141

DO - 10.1016/j.chemosphere.2018.11.141

M3 - Article

C2 - 30502700

AN - SCOPUS:85059309649

SN - 0045-6535

VL - 218

SP - 616

EP - 623

JO - Chemosphere

JF - Chemosphere

ER -

Estimating n-octanol-water partition coefficients for neutral highly hydrophobic chemicals using measured n-butanol-water partition coefficients

Abstract

Bibliographical note

Keywords

Access

OpenUrl availability

Other files and links

Fingerprint

Cite this