[1,1'-Biphenyl]-2,2'-diol, 3,3'-bis(1,1-dimethylethyl)-5,5'-dimethoxy-

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

between 08 January 2009 and 01 April 2009.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do no effect the quality of the relevant results

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

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

Test guideline 2

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 19/08/08 Date of Signature: 04/03/09

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Test material

Test material information

Constituent 1

Reference substance name:

EXAMPLE: Indicate the identity for one or more appropriate identifiers, e.g. CAS number, CAS name, IUPAC name. Copy this block of fields as appropriate.

IUPAC Name:

EXAMPLE: Indicate the identity for one or more appropriate identifiers, e.g. CAS number, CAS name, IUPAC name. Copy this block of fields as appropriate.

Details on test material:

Sponsor's identification : L17_Precursor
Description : pale yellow powder
Chemical name : 5,5-dimethoxy-3,3’-di-tert-butyl-2,2’-biphenol
CAS number : 14078-41-2
Purity : 93.4%
Batch number : DALA046312
Date received : 11 November 2008
Storage conditions : room temperature in the dark

Radiolabelling:

no

Study design

HPLC method

Details on study design: HPLC method:

EEQUIPMENT
- Apparatus:
The sample, dead time and reference standard solutions were injected in duplicate using the following HPLC parameters:
HPLC System : Agilent Technologies 1100, incorporating autosampler and workstation
Column : Zorbax SB-CN 5μ (250 x 4.6 mm id)
Column temperature : 30ºC
Mobile phase : methanol:water (55:45 v/v)
pH of mobile phase : 6.0
Flow-rate : 1.0 ml/min
Injection volume : 10 µl
UV detector wavelength : dead time and reference standards: 210 nm
sample : 300 nm


DETERMINATION OF DEAD TIME
The dead time was determined by measuring the retention time of formamide (purity* ≥99.5%, 505 mg/l solution in mobile phase).


REFERENCE SUBSTANCES
- Identity:
Solutions of reference standards (see following table) were prepared in methanol.

Standard Purity (%)* Concentration (mg/l)
Acetanilide 99+ 104
Phenol 99+ 118
Atrazine 97.4 100
Isoproturon 99.8 100
Triadimenol 98.4 112
Linuron 99.5 103
Naphthalene ≥99.0 110
Endosulfan-diol 99.8 105
Fenthion 97.8 126
-Endosulfan 99.6 120
Phenanthrene ≥97.0 104
Diclofop-methyl 99.5 106
DDT 98 104


DETERMINATION OF RETENTION TIMES
The mobile phase was ramped to 100% methanol after the retention time of DDT to elute any highly retained components of the test material.

EVALUATION
- Calculation of capacity factors k':

k= tr- to/ to
where:
k = capacity factor

tr = retention time (min)

t0 = dead time (min)

Batch equilibrium or other method

Analytical monitoring:

no

Details on sampling:

Not applicable

Details on matrix:

Not applicable

Details on test conditions:

Not applicable

Computational methods:

Not applicable.

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Value:

205 000

Adsorption coefficient 2

Type:

log Koc

Value:

5.31

Results: HPLC method

Details on results (HPLC method):

The retention times of formamide and the retention times, capacity factors (k) and log10 Koc values for the reference standards are shown in Tables 1 and 2

Adsorption coefficient of sample
The retention times, capacity factors and log10 Koc values determined for the sample are shown below:

Injection Retention Time (mins) Capacity Factor (k) Log10 k Log10 Koc
1 50.928 17.0 1.23 5.31
2 50.871 17.0 1.23 5.31

Mean log10 Koc: 5.31
Adsorption coefficient: 2.05 x 105

Discussion:
Although the main peak in the chromatography (as shown in attachment 1) that represents the test material eluted before DDT, and so within the range of the calibration curve, a ramp to 100% methanol after the retention time of DDT was performed to show that there were no more significant components in the test material. A chromatogram of a sample blank was subtracted from the chromatograms of the sample to remove the baseline drift due the mobile phase gradient.

Results: Batch equilibrium or other method

Statistics:

None stated.

Any other information on results incl. tables

Calibration

The retention times of formamide and the retention times, capacity factors (k) and log₁₀K_ocvalues for the reference standards are shown in the two following tables below:

Table 1:

Dead Time	Retention Time (mins)		Mean Retention Time (mins)
	Injection 1	Injection 2
Formamide	2.828	2.827	2.828

Table 2:

Standard	Retention Time (mins)		Mean Retention Time (mins)	Capacity Factor (k)	Log10k	Log10Koc
	Injection 1	Injection 2
Acetanilide	3.983	3.983	3.983	0.409	-0.389	1.25
Phenol	3.790	3.797	3.794	0.342	-0.466	1.32
Atrazine	5.829	5.826	5.828	1.06	2.57 x 10^-2	1.81
Isoproturon	6.217	6.217	6.217	1.20	7.87 x 10^-2	1.86
Triadimenol	8.524	8.525	8.525	2.02	0.304	2.40
Linuron	9.037	9.037	9.037	2.20	0.342	2.59
Naphthalene	7.620	7.618	7.619	1.70	0.229	2.75
Endosulfan-diol	11.017	11.024	11.021	2.90	0.462	3.02
Fenthion	14.494	14.494	14.494	4.13	0.616	3.31
a-Endosulfan	20.926	20.930	20.928	6.40	0.806	4.09
Phenanthrene	16.539	16.553	16.546	4.85	0.686	4.09
Diclofop-methyl	23.479	23.469	23.474	7.30	0.863	4.20
DDT	50.123	50.157	50.140	16.7	1.22	5.63

 

Adsorption coefficient of sample

The retention times, capacity factors and log₁₀K_ocvalues determined for the sample are shown in the following table:

Table 3:

Injection	Retention Time (mins)	Capacity Factor (k)	Log10k	Log10Koc
1	50.928	17.0	1.23	5.31
2	50.871	17.0	1.23	5.31

Mean log₁₀K_oc:                     5.31
Adsorption coefficient:        2.05 x 10⁵

Discussion

Although the main peak in the chromatography that represents the test material eluted before DDT, and so within the range of the calibration curve, a ramp to 100% methanol after the retention time of DDT was performed to show that there were no more significant components in the test material. A chromatogram of a sample blank was subtracted from the chromatograms of the sample to remove the baseline drift due the mobile phase gradient.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient (Koc) of the test material has been determined to be 2.05 x 10E5, log10 Koc 5.31.

Executive summary:

Method

The determination was carried out using the HPLC screening method, Method C19 of Commission Directive 2001/59/EC (which constitutes Annex V of Council Directive 67/548/EEC), Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.

Discussion

Although the main peak in the chromatography that represents the test material eluted before DDT, and so within the range of the calibration curve, a ramp to 100% methanol after the retention time of DDT was performed to show that there were no more significant components in the test material. A chromatogram of a sample blank was subtracted from the chromatograms of the sample to remove the baseline drift due the mobile phase gradient.

Conclusion

The adsorption coefficient (K_oc) of the test material has been determined to be 2.05 x 10⁵, log₁₀K_oc 5.31.