Octanol-Water Partition Coefficient, Kow
Water Quality Testing
WESHIN INSPECTION TECH CO., LTD_

n-Octanol/Water Partition Coefficient log Pow

 

Quantifying lipophilicity to predict environmental fate and bioaccumulation potential.
 

The n-octanol/water partition coefficient ($\log P_{ow}$) describes how a chemical distributes itself between an organic solvent (1-octanol) and water. At Weshin Inspection Tech , we conduct partition coefficient studies following OECD Test Guidelines (TG 107, 117, 123) to provide essential data for REACH registration, agrochemical dossiers, and PBT assessments.


The Critical Importance of log Pow

 

As a fundamental physico-chemical property, log Pow is a key driver in environmental risk assessment:

  • Bioaccumulation Prediction: High log Pow values indicate a propensity for the substance to accumulate in the fatty tissues of organisms.

  • Environmental Mobility: It dictates whether a substance will partition into soil and sediments or remain dissolved in water, moving through aquatic systems.

  • Toxicokinetics & Permeability: Lipophilicity is a major determinant of how easily a chemical crosses biological membranes and exerts toxicological effects.

  • Regulatory Compliance: A mandatory parameter for identifying Persistent, Bioaccumulative, and Toxic (PBT) substances under global chemical frameworks.
     

Our Testing Methodologies

 

Weshin Inspection Tech selects the most robust method based on the substance's expected hydrophobicity:

  • Shake Flask Method (OECD TG 107): The standard approach for substances with log Pow between -2 and 4.

  • HPLC Method (OECD TG 117): A rapid estimation technique for substances with log Pow in the range of 0 to 6, based on correlation with retention times.

  • Slow-Stirring Method (OECD TG 123): The highly accurate "gold standard" for extremely lipophilic substances (up to log Pow 8.2), eliminating errors caused by micro-emulsions.
     

Why Partner with Weshin Inspection Tech?

 

  • Full Spectrum Capability: Delivering reliable data across the entire hydrophobicity scale, from highly polar to ultra-lipophilic compounds.

  • Advanced Analytical Detection: Utilizing LC-MS/MS and GC-MS for high-sensitivity quantification of test substances in both aqueous and organic phases.

  • pH-Adjusted Testing: For ionizable substances, we provide $\log P_{ow}$ determination at environmentally relevant pH levels to ensure data accuracy for acidic or basic compounds.


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