4-(4-isopropoxyphenylsulfonyl)phenol

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2003-03-04 to 2003-04-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

2001/59/EC

Deviations:

no

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))

Version / remarks:

2001-01-22

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

Not indicated

Details on study design: HPLC method:

HPLC System: Agilent Technologies 1050, incorporating autosampler and workstation;
Column: Genesis 4µCN (250 x 4.6 mm i.d.);
Column temperature: 40 °C;
Mobile phase: Determination 1: methanol/water (55 : 45 v/v) adjusted to pH 5.5 using acetic acid;
Determination 2: methanol : water (55 : 45 v/v) adjusted to pH 9 using 0.1 M sodium hydroxide;
pH of mobile phase: Determination 1: 5.5
Determination 2: 9.0;
Flow rate: 1 mL/min;
UV detector wavelength: dead time and reference standards: 210 nm;
sample: 254 nm;
Injection volume: 10 µL;

Key result

Type:

Koc

Value:

258 dimensionless

pH:

5.5

Key result

Type:

log Koc

Value:

2.41 dimensionless

pH:

5.5

Type:

Koc

Value:

28.4 dimensionless

pH:

9

Type:

log Koc

Value:

1.45 dimensionless

pH:

9

Details on results (HPLC method):

Adsorption coefficient of sample:
Determination 1 (pH 5.5):
Injection 1/ Injection 2:
Retention time (min): 4.938/4.953;
Capacity factor (k) 0.662/0.667;
log10k: -0.179/-0.176;
log10Koc: 2.40/2.42;
Mean log10Koc: 2.41;
Adsorption coefficient: 258;

Determination 2 (pH 9.0):
Injection 1/ Injection 2:
Retention time (mins): 4.101/4.107;
Capacity factor (k) 0.376/0.378;
log10k: -0.424/-0.422;
log10Koc: 1.45/1.46;
Mean log10Koc: 1.45;
Adsorption coefficient: 28.4

The retention times, capacity factors and log10Koc values for the sample are shown in the following tables:

Table 1: Determination 1 - pH 5.5:

Injection	Retention Time (mins)	Capacity Factor (k)	log10k	log10Koc
1	4.938	0.662	-0.179	2.40
2	4.953	0.667	-0.176	2.42

Mean log10 Koc: 2.41

Adsorption coefficient: 258

Table 2: Determination 2 - pH 9.0

Injection	Retention Time (mins)	Capacity Factor (k)	log10k	log10Koc
1	4.101	0.376	-0.424	1.45
2	4.107	0.378	-0.422	1.46

Mean log10 Koc: 1.45

Adsorption coefficient: 28.4

Validity criteria fulfilled:

yes

Conclusions:

At the pH 5.5, the adsorption coefficient Koc was determined to be 258 and the logKoc to be 2.41, respectively. At pH 9.0 Koc was determined to be 28.4 and the logKoc to be 1.45, respectively.

Executive summary:

The adsorption coefficient of D-8 was determined using the HPLC method according to EU Method C.19 and OECD 121. The guidelines state that the measurement should be carried out on substances in their ionised and unionised forms. This is applicable if the test material has a dissociation constant which falls within the pH range of approximately 5.5 to 7.5 and more than 10 % of the test material could be ionised in this pH range. D-8 was predicted to have a dissociation constant of approximately 7.3 for the OH group adjacent to the aromatic ring. Therefore, testing was carried out at the two pH limits of the test (5.5 and 9.0) with the test material being ionised at pH 9.0 and unionised at pH 5. At the pH 5.5, the adsorption coefficient Koc was determined to be 258 and the logKoc to be 2.41, respectively. At pH 9.0 Koc was determined to be 28.4 and the logKoc to be 1.45, respectively.

Description of key information

At the pH 5.5, the adsorption coefficient Koc was determined to be 258 and the logKoc to be 2.41, respectively. At pH 9.0 Koc was determined to be 28.4 and the logKoc to be 1.45, respectively. According to OECD 121, the environmental relevant pH range is between 5.5 and 7.5, therefore, the Koc determined at pH 5.5 is used as key value for further risk assessment and PNEC derivation.

Key value for chemical safety assessment

Koc at 20 °C:

258

Additional information

The adsorption coefficient of D-8 was determined using the HPLC method according to EU Method C.19 and OECD 121. The guidelines state that the measurement should be carried out on substances in their ionised and unionised forms. This is applicable if the test material has a dissociation constant which falls within the pH range of approximately 5.5 to 7.5 and more than 10 % of the test material could be ionised in this pH range. D-8 was predicted to have a dissociation constant of approximately 7.3 for the OH group adjacent to the aromatic ring. Therefore, testing was carried out at the two pH limits of the test (5.5 and 9.0) with the test material being ionised at pH 9.0 and unionised at pH 5. At the pH 5.5, the adsorption coefficient Koc was determined to be 258 and the logKoc to be 2.41, respectively. At pH 9.0 Koc was determined to be 28.4 and the logKoc to be 1.45, respectively.