4-chloro-3,5-xylenol

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

other: methanol: water (75:25 v/v)

Test material

Test material information

Constituent 1

Reference substance name:

4-chloro-3,5-xylenol

EC Number:

201-793-8

EC Name:

4-chloro-3,5-xylenol

Cas Number:

88-04-0

Molecular formula:

C8H9ClO

IUPAC Name:

4-chloro-3,5-dimethylphenol

Test material form:

solid: crystalline

Details on test material:

Sponsor's identification
Description
Batch number
Date received
Storage conditions
PCMX
cream coloured, crystalline solid
285/13847
27 September 2001
room temperature, in the dark

Specific details on test material used for the study:

Sponsor's identification
Description
Batch number
Date received
Storage conditions
PCMX
cream coloured, crystalline solid
285/13847
27 September 2001
room temperature, in the dark
Sample solutions were prepared in stoppered glass flasks at a nominal concentration of
5.0 x 10·2 g/l in the three buffer solutions.
The solutions were shielded from light whilst maintained at the test temperature.

Radiolabelling:

no

Study design

Test temperature:

25C

HPLC method

Details on study design: HPLC method:

The sample, formamide and reference standard solutions were injected in duplicate using the
following HPLC parameters:
HPLC System
Column
Column temperature
Mobile phase
pH of mobile phase
Flow-rate
UV detector wavelength
Injection volume
Construction of calibration curve
Agilent Technologies 1100, incorporating
autosampler and workstation
Luna 5μ CN (250 x 4.6 mm id)
30°C
methanol: water (55:45 v/v)
6.2
1.0 ml/min
dead time and reference standards: 210 nm
sample: 221 nm
10 μl

Batch equilibrium or other method

Details on sampling:

.

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Key result

Sample No.:

#1

Type:

log Koc

Value:

2.08

Temp.:

25 °C

Adsorption coefficient 2

Key result

Sample No.:

#2

Type:

log Koc

Value:

2.08

Temp.:

25 °C

Results: HPLC method

Details on results (HPLC method):

Table 5.4
Injection
Retention Time Capacity Factor (k) (mins) log10 k log10 Koc
I 4.562 0.328 -0.485 2.08
2 4.561 0.327 -0.485 2.08
Mean log10 Koc: 2.08
Adsorption coefficient: 120

Any other information on results incl. tables

Table 5.4

Injection

Retention Time Capacity Factor (k) (mins) log10 k log10 Koc

I 4.562 0.328 -0.485 2.08

2 4.561 0.327 -0.485 2.08

Mean log10 Koc: 2.08

Adsorption coefficient: 120

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient (Koc) of the test material has been determined to be 120, log10 Koc 2.08.

Executive summary:

The method guideline states that the measurement of adsorption coefficient should be carried out

on substances in their ionised and unionised forms. However, the dissociation constants of certain

functional groups found in the test material made it impossible to satisfy this criteria. Testing

would be required at pH 11 or above to obtain the hydroxyl group in an ionised form. The

dissociation constant of the hydroxyl group was estimated to be 9.8. As a consequence of this, the

functional group will always be present in its unionised form. Therefore, as pH 11 or above is

outside the environmental pH range for this test and also experimentally impractical, testing was

carried out at approximately neutral pH with the functional group unionised only.