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Environmental fate & pathways

Adsorption / desorption

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Administrative data

Endpoint:
adsorption / desorption
Remarks:
adsorption
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This study was not a standardized method, but it was well described. No information was available about the purity of the test substance.

Data source

Reference
Reference Type:
publication
Title:
Adsorption of substituted phenols by soil
Author:
Boyd S.A
Year:
1982
Bibliographic source:
Soil Science, 134 : 337-343

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Soil adsorption isotherm
GLP compliance:
not specified
Type of method:
batch equilibrium method
Media:
soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Phenols used in this study were obtained from Aldrich Chemical Co., Eastman Kodak Co., and Mallinckrodt and used without further purification
Radiolabelling:
no

Study design

Batch equilibrium or other method

Analytical monitoring:
yes
Details on matrix:
A Brookston clay loam soil obtained from the Michigan State University Soils Research Farm, Eas Lansing, Michigan, was used in this study. Samples were collected from the top 15 cm of the soil profile, air-dried, and ground to pass through an 18-mesh (1-mm) screen.
Details on test conditions:
Batch equilibrations were set up inside an anaerobic glovebox using a 1:10 soil:solution ratio and 5 initial concentrations of Guaiacol : 5, 10, 20, 30 and 50 ppm.

Triplicate samples were measured for each initial concentration.

Aqueous solutions (100 mL) of Guaiacol were prepared in 0.0025 M CaCl2 that had been deoxygenated by purging for 10 min. with purified N2. For isotherm of Guaiacol, 152.5 g of soil samples were weighed into 50-mL Oak Ridge-type polypropylene centrifuge tubes and transferred into an anaerobic glove box. 25-mL aliquots of Guaiacol solution were added to triplicate soil samples, and remaining 25 mL aliquot was saved for use as an analytical standard. The centrifuge tubes were subsequently capped, removed from the glove box, and shaken for 24 h at 20+/-1°C. At the end of the 24 h equilibration period, the samples were centrifuged at 20 000 g for 20 min. in a refrigerated centrifuge set at 20°C.
Portion of the aqueous phase was then filtered through small glass wool plugs held in 9-in. Pasteur pipets. Samples were collected in glass vials, capped, and analysed immediately, using HPLC.
Duration of adsorption equilibration
Duration:
24 h
Temp.:
20

Results and discussion

Adsorption coefficient
Type:
Koc
Value:
40.01

Applicant's summary and conclusion

Executive summary:

Adsorption isotherms of guaiacol have been determined using a Brookston clay loam soil, a soil:solution ratio of 1:10 and 5 initial concentrations (5, 10, 20, 30 and 50 ppm).

The measured soil organic carbon partition coefficient Koc was 40.01.

Based on this result, guaiacol is not considered to be a highly adsorptive substance.