2,2''-dihydroxy-4,4''-(2-hydroxy-propane-1,3-diyldioxy)dibenzophenone

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Principles of method if other than guideline:

The determination was carried out using an HPLC screening method. The procedure employed is that outlined in the draft "HPLC-Screening Method for the Determination of the Adsorption-Coefficient on Soil-Comparison of Different Stationary Phases", W. Kördel, J. Stutte and G. Kotthoff, Faruenhofer - Institut für Umweltchemieand Ökotoxikologie.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

424-210-0

EC Name:

-

Cas Number:

23911-85-5

Molecular formula:

C29 H24 O7

IUPAC Name:

2-benzoyl-5-[3-(4-benzoyl-3-hydroxyphenoxy)-2-hydroxypropoxy]phenol

Radiolabelling:

no

Study design

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: not specified
- Type: not specified
- Type, material and dimension of analytical (guard) column: Spherisorb 5 CN (250 x 4.6 mm i.d.)
- Detection system: UV, 240 nm - dead time and standard solutions 254 nm - sample solution

MOBILE PHASES
- Type: methanol:water (55:45)
- Experiments with additives carried out on separate columns: yes / no
- pH: 7.52
- Solutes for dissolving test and reference substances: methanol

DETERMINATION OF DEAD TIME
- Method: The dead time was determined by measuring the retention time of a 1.05 x 10E4 mg/I solution of formamide (purity 99.5%*) in methanol.
* value quoted by supplier.

REFERENCE SUBSTANCES
- Identity: A reference standard of fenoxaprop-ethyl (purity 98.9%*) was prepared in methanol at a concentration of 420 mg/I.
* value quoted by supplier.

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: An aliquot (0.0250 g) of test material was diluted to 50 ml with methanol. Injection volume 25 µL
- Quantity of reference substances: not specified
- Intervals of calibration: not specified

REPETITIONS
- Number of determinations: 2 (sample and reference)

EVALUATION
- Calculation of capacity factors k': k=(tR - t0)/t0, where tR=retention time of the substance (mins) and t0=dead time (mins)
- Calculation of retention times: measured
- Determination of the log Koc value: The log Koc of the sample was deduced by direct comparison of the sample retention time with that of a standard having a high log Koc value.

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Key result

Type:

Koc

Value:

> 7 410

Adsorption coefficient 2

Key result

Type:

log Koc

Value:

> 3.87

Results: HPLC method

Details on results (HPLC method):

- Retention times of reference substances used for calibration: mean value of 2 injections 6.029 min
- Details of fitted regression line (log k' vs. log Koc): k=1.038; log k=0.01614; logKoc=3.87
- Average retention data for test substance: 7.8025 min

Applicant's summary and conclusion

Conclusions:

The logKoc of the sample was deduced by direct comparison of the sample retention time with that of a standard having a high logKoc value. The soil adsorption coefficient (Koc) of FADEX He 1819 PK has been determined to be greater than 7410, logKoc > 3.87.