Registration Dossier

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2001-02-12
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study E121 (draft), GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))
Version / remarks:
draft
GLP compliance:
yes
Type of method:
HPLC estimation method
Media:
soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 1,6-Hexanediol dimethacrylate
- Substance type: organic
- Physical state at room temperature: liquid
Radiolabelling:
no

Study design

HPLC method

Details on study design: HPLC method:
EQUIPMENT
- Apparatus: HPLC Pump SP 8810, Spectra-Physics Inc.
- Type: Differential Refractometer, Knauer Inc.
- Type, material and dimension of analytical (guard) column: Zorbax CN, 250 x 4.0 mm, 5 µm
- Detection system: refractive index

MOBILE PHASES
- Type: methanol/ water (purified) 55/45 (v/v)
- Experiments with additives carried out on separate columns: no
- Flow velocity: 1.0 mL/min
- Injection volume: 20 µL
- Temperature: 24 °C
- Detection: refractive index

DETERMINATION OF DEAD TIME
- Method: by means of homologous series / by inert substances which are not retained by the column

REFERENCE SUBSTANCES
- Identity:
(0) Urea (inert marker) 20.4 mg/25 ml eluent
(1) Acetanilide 16.7 mg/25 ml solvent
(2) Monuron 15.1 mg/25 ml solvent
(3) Triapenthenol 12.7 mg/25 ml solvent
(4) Linuron 15.4 mg/25 ml solvent
(5) Fenthion 16.2 mg/25 ml solvent
(6) Trifluralin 15.3 mg/25 ml solvent

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 25 mL
- Quantity of reference substances: 25 mL
- Intervals of calibration:
- Test item: 1,6-Hexanediol dimethacrylate 48.6 mg/25ml
- Solvent: methanol/ water (purified): 70/30 (v/v)

REPETITIONS
- Number of determinations: 2

EVALUATION
The distribution coefficient (Kd) is defined as the ratio of equilibrium concentrations c of a dissolved test substance in a two phase system consisting of a sorbent (soil or sewage sludge) and an aqueous phase: c(soil)
Kd = -------------
c(water)
The adsorption coefficient (Koc) is defined as the distribution coefficient Kd normalised to the organic carbon content foc of a sorbent:
Kd
foc = ------------
foc
For the determination of the adsorption coefficient of 1,6-Hexanediol dimethacrylate the HPLC method was chosen.
With the HPLC method the retention of the test material in a HPLC system is compared with the retention of at least six calibration substances with
known Koc values.

- Calculation of capacity factors k': tR - t0
k'= -------------
t0
(where tR is the retention time of the test substance, and to is the dead time, i.e. the average time a solvent molecule needs to pass the column) and
using a calibration plot of log k' versus log Koc of the selected reference compounds.
The adsorption coefficient (Koc) of the test substance is given as its log Koc value.

Results and discussion

Adsorption coefficientopen allclose all
Type:
Koc
Value:
501
Remarks on result:
other: ambient temperature
Type:
log Koc
Value:
2.7
Remarks on result:
other: ambient temperature

Results: HPLC method

Details on results (HPLC method):
Summary of the results of the HPLC measurements of the reference (calibration) substances


No. tR1 [min] tR2 [min] tR [min] k' log k'(x) log Koc (y)
--------------------------------------------------------------------------------------------
0 2.35 2.35 2.35 --- --- ---
1 3.38 3.39 3.39 0.443 -0.354 1.61
2 4.65 4.65 4.65 0.979 -0.009 1.99
3 7.09 7.06 7.08 2.013 0.304 2.37
4 8.53 8.49 8.51 2.621 0.418 2.62
5 17.43 17.28 17.36 6.387 0.805 3.30
6 35.87 35.34 35.61 14.153 1.151 3.92
--------------------------------------------------------------------------------------------

The linear regression of the log k' of the calibration substances against their log Koc has a correlation coefficient of r = 0.9932.

From the retention times of the test item 1,6-Hexanediol dimethacrylate the corresponding k'-value was calculated and with the function above the
log Koc of 1,6-Hexanediol dimethacrylate was determined by interpolation to:

tR k' log k' log Koc log Koc
mean value
------------------------------------------------------------------
8.88 2.779 0.444 2.73
2.7
8.77 2.732 0.436 2.71
------------------------------------------------------------------

There is no greater difference than 0.1 between the two log Koc values and the corresponding mean value.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The adsorption coefficient on soil (Koc) of 1,6-Hexanediol dimethacrylate was determined according OECD Draft guideline No.121 (HPLC method)
and was found to be Koc = 501 (log Koc = 2.7).
Executive summary:

The adsorption coefficient on soil (Koc) of 1,6-Hexanediol dimethacrylate was determined according OECD Draft guideline No.121 (HPLC method) and was found to be Koc = 501 (log Koc = 2.7).

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.