Registration Dossier

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2002-04-17 until 2002-06-24
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP 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:
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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material: Tri (hexyl, octyl, decyl)-citrat
- Substance type: Product
- Physical state: Colourless liquid
- Analytical purity: 99.9%
- Lot/batch No.: 00073032
- Storage condition of test material: room temperature
Radiolabelling:
no

Study design

Test temperature:
25 °C

HPLC method

Details on study design: HPLC method:
EQUIPMENT
- Apparatus: pump: Jasco PU980
- Type, material and dimension of analytical (guard) column: Zorbax CN, 25x0.46 cm
- Detection system: Jasco UV-975 set to 220 nm

MOBILE PHASES
- Type: Methanol-water, 55:45
- flow rate: 1.0 mL/min
- pH: not mentioned
- Solutes for dissolving test and reference substances: mobile phase

DETERMINATION OF DEAD TIME
- Method: by means of homologous series / by inert substances which are not retained by the column: was measured using formamide as a non-retained solute.

REFERENCE SUBSTANCES
- Identity: Acetanilide; N,N-dimethylbenzamide; methyl benzoate; aniline; linuron; naphthalene; fenthion; phenanthrene; DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 26.82 µg
- Quantity of reference substances: 0.05 µg Acetanilide; 0.05 µg N,N-dimethylbenzamide; 0.06 µg methyl benzoate; 0.05 µg aniline; 0.05 µg linuron; 0.01 µg naphthalene; 0.28 µg fenthion; 0.05 µg phenanthrene; 0.28 µg DDT
- Intervals of calibration: two calibration lines were constructed, each containg six calibration substances. Part 1 included acetanilide; N,N-dimethylbenzamide; methyl benzoate; linuron; naphthalene; fenthion. Part 2 included: aniline; linuron; naphthalene; fenthion; phenanthrene; DDT.

REPETITIONS
- Number of determinations: two runs

EVALUATION
- Calculation of capacity factors k': the capacity factor, k, may be calculated from the retention time: k = (TR - T0)/T0 (TR = retention time for the calibration substances, and T0 is that for the void volume marker. The log of the capacity factor is plotted against the log of the adsorption coefficient to derive calibration graph: log k = slope x log Koc + constant.
- Calculation of retention times: KPLC retention data are generated for a series of calibration substances and the test substance.
- Determination of the log Koc value: The estimated adsorption coefficient is then calculated from the calibration graph obtained using the calibration substances: log Koc = (log k - constant)/slope. Consideration of the fiducial limits according to Fieller's Theorem permits derivation of the 95% confidence interval for the results.

Batch equilibrium or other method

Analytical monitoring:
no

Results and discussion

Adsorption coefficient
Type:
log Koc
Value:
> 5.5 - < 6.5
Temp.:
25 °C

Results: HPLC method

Details on results (HPLC method):
- Retention times of reference substances used for calibration:
Run 1: min log k Run 2 min log k
Formamide: 3.173 - 3.177 -
Acetanilide: 3.920 -0.628 3.907 -0.639
N,N-dimethylbenzamide: 4.180 -0.499 4.177 -0.502
Methyl benzoate: 4.618 -0.342 4.610 -0.346
Aniline: 5.610 -0.115 5.313 -0.172
Linuron: 6.203 -0.020 6.213 -0.020
Naphthalene: 6.247 -0.014 6.247 -0.015
Fenthion: 8.990 0.263 8.998 0.263
Phenanthrene: 10.177 0.344 10.193 0.344
DDT: 18.057 0.671 18.070 0.671

- Details of fitted regression line (log k' vs. log Koc):
The two calibration lines were highly linear:
Run 1 Part 1: Slope = 0.4215; Intercept = -1.1353; Correlation = 0.9937
Run 1 Part 2: Slope = 0.2265; Intercept = -0.5832; Correlation = 0.9699
Run 2 Part 1: Slope = 0.4255; Intercept = -1.1472; Correlation = 0.9933
Run 2 Part 2: Slope = 0.2358; Intercept = -0.6246; Correlation = 0.9679

- Average retention data for test substance: The test substance eluted as three evaluated components:
Run 1 Peak 1: 3.0275 min; log Koc: cannot be evaluated
Run 1 Peak 2: 18.0500 min; log Koc: 5.54
Run 1 Peak 3: 27.5900 min; log Koc: 6.49

Run 2 Peak 1: 3.0325 min; log Koc: cannot be evaluated
Run 2 Peak 2: 18.1475 min; log Koc: 5.51
Run 2 Peak 3: 27.7175 min; log Koc: 6.42

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

The test substance eluted as three evaluated components:

11.5% by peak area eluted at a shorter retention time than that of the void volume marker compound formamide, and the log Koc value cannot therefore be defined.

73.4% by peak area eluted at a retention time equivalent to a log Koc value of 5.5, and within a 95% confidence area of 5.0 to 6.3.

15.1% by peak area eluted at a retention time equivalent to a log Koc value of 6.5, and within a 95% confidence area of 5.8 to 7.5.