4,4'-[(1,10-dioxodecane-1,10-diyl)bis(oxy)]bis(2,2,6,6-tetramethylpiperidine-1-oxidanyl)

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

equivalent or similar 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:

not specified

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil

Test material

Test material information

Constituent 1

Reference substance name:

1,10-bis(2,2,6,6-tetramethyl-1-piperidinyloxy)-1,10-dioxodecane

EC Number:

417-440-8

EC Name:

1,10-bis(2,2,6,6-tetramethyl-1-piperidinyloxy)-1,10-dioxodecane

Cas Number:

2516-92-9

Molecular formula:

C28 H50 N2 O6

IUPAC Name:

bis(1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl) decanedioate

Details on test material:

Batch: CXA681901

Radiolabelling:

no

Study design

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus:
HPLC pump: M 480, from Gynkotek, Munchen, BRD
Degasser: DG-1300, from Gynkotek, Munchen, BRD
Autosampler: Gina M 160, from Gynkotek, Munchen, BRD
Thermostat: MGW Lauda RM 20, from MGW, Lauda-Konigshofen, BRD
Chromatographic data system: PC AT486 with GYNKOSOFT Version 5.50, from Gynkotek, Munchen, BRD
Stationary phase: cyanopropyl (5 pm, Zorbax CN), from VDS Optilab, Berlin, BRD
Injection volume: variable between 10 pl and 200 pl
Flow rate: 1.0 ml/min
Spectrometer: Lambda 5 UV/VIS-Spektrometer (Perkin-Elmer, Uberlingen, BRD)
- Type, material and dimension of analytical (guard) column:
Column thermostat: Cosytherm, from Labor Technik Barkey, Bielefeld, BRD
Column temperature: 40°C
Column dimensions: 250x4.6 mm
- Detection system:
Diode array detector: UVD 320, from Gynkotek, Munchen, BRD

MOBILE PHASES
- Type: not specified
- Experiments with additives carried out on separate columns: no
- pH: 6
- Solutes for dissolving test and reference substances:
methanol: 0.01 mol/l citrate buffer pH 6.0 = 55 : 45 / v:v

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column
In this study Forrnamide was used as inert substance.
Preparation of solution: 10.5 mg Formamide were dissolved in 10 ml of methanol. An aliquot of this solution was chromatographed under standard chromatographic conditions and the retention time was determined.

REFERENCE SUBSTANCES
N-Phenylacetamide
Atrazine
Monuron
Triapenthenol
Linuron
Fenthion
Trifluralin

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column:
A stock solution of the test substance was prepared by dissolving 10.19 mg in 10 ml of methanol. 490 pl of the stock solution were diluted to 10 ml with methanol.
- Quantity of reference substances:
A stock solution of each reference substance was prepared by dissolving approximately 10 mg in 10 ml of methanol. The stock solutions were diluted 1:100 with methanol.
- Intervals of calibration:
The calibration was performed at regular inten/als in duplicate at least once daily, so that possible changes in column performance could have been allowed for.

REPETITIONS
- Number of determinations: once

EVALUATION
- Calculation of capacity factors k': k' = (tR-tO)/tO.
tR = retention time of test substance or reference substance; tO= column dead time (retention time of formamide)
- Calculation of retention times: measured
- Determination of the log Koc value: Log Koc of the test substance was calculated from the fitted regression line (log k' versus logKoc).

Results and discussion

Adsorption coefficient

Sample No.:

#1

Type:

log Koc

Value:

3.58 dimensionless

pH:

6

Results: HPLC method

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
N-Phenylacetamide: 3.34 min
Atrazine: 3.82 min
Monuron: 3.94 min
Triapenthenol: 4.86 min
Linuron: 5.00 min
Fenthion: 6.65 min
Trifluralin: 10.01 min
- Details of fitted regression line (log k' vs. log Koc):
log Koc = 2.239 • log k' + 2.874.
coefficient of correlation = 0.979
- Graph of regression line attached: see figure
- Average retention data for test substance: 8.49 min

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The determination of the adsorption coefficient (log Koc) of CXA 5415 (TK A 40075) on soil by means of a HPLC-screening method gave the following result:
log Koc = 3.58

Executive summary:

The determination of the adsorption coefficient (log Koc) of CXA 5415 (TK A 40075) on soil by means of a HPLC-screening method gave the following result:

log Koc = 3.58

A suitable set of reference substances with adsorption coefficients (log Koc), which had been determined using the OECD guideline 106, and the test substance were chromatographed under standard chromatographic conditions and their retention times (t„) were determined. Using the retention times and the column dead time (t„), which was determined by means of formamide, the corresponding capacity factors (k') were calculated. The log k' of the reference substances and their log Koc-values were used to construct a calibration plot of log k' versus log Koc. The adsorption-coefficient (log Koc) of the test substance was calculated using the log k' of the test substance and the fitted regression line.