Hexanamide, N-(2-hydroxyethyl)-3,5,5-trimethyl-

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

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

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Test temperature:

25 ± 1°C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Waters 2695 with Waters 486 uv detector
- Type: HPLC -UV
- Type, material and dimension of analytical column: Zorbax CN RP 250 x 4.6 mm, 5 μm
- Detection system: UV at 210 nm

MOBILE PHASES
- Type: 55/45 Methanol/0.01M Citrate buffer (pH 6.0)
- Experiments with additives carried out on separate columns: no
- pH: 6.0
- Solutes for dissolving test and reference substances: Methanol: Milli-Q water (55:45 v/v)

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column - Formamide

REFERENCE SUBSTANCES
- Identity: Formamide, Acetanilide, Methyl Benzoate, Naphthalene, 1,2,3-Trichlorobenzene, Phenanthrene and DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 40 µg
- Quantity of reference substances: Formamide (1.2 µg), Acetanilide (0.2 µg), Methyl Benzoate (0.2 µg), Naphthalene (0.04 µg), 1,2,3-Trichlorobenzene (0.4 µg), Phenanthrene (0.4 µg) and DDT (0.8 µg)
- Intervals of calibration: reference substance injections bracketing 2 test item injections

REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': k′ =(tR - to)/to
tR : HPLC retention time of test and reference substance (minutes)
to : HPLC dead time (minutes)

Log10 k’ was then calculated for each reference compound

- Calculation of retention times: Automatic peak retention time parameters by Thermo Labsystems Atlas 2002, Release 1 Data Handling

- Determination of the log Koc value:
Additol® SXW 6246/90 coating additives is present as a complex reaction product of variable compocition. The chromatographic end-point was designed to determine the test item's principal hydrocarbon components Koc. A range of components were found to be present in Additol® SXW 6246/90 coating additives.
Following chromatography, a correlation graph was produced for the reference standard mix by plotting Log10 k’ value versus Log10 KOC value, for each compound. Literature Log10 KOC values were obtained from OECD Guideline 121.
A Log10 KOC value for each component of the test item was then extrapolated from the correlation graph of the reference standard mix run immediately adjacent to it.

Type:

log Koc

Value:

>= 1.04 - <= 1.14 dimensionless

Temp.:

25 °C

Remarks on result:

other: Principal Component (72.7-74.4% total peak area): Koc >=11.0 <=13.8

Type:

log Koc

Value:

>= 3.55 - <= 3.57 dimensionless

Temp.:

25 °C

Remarks on result:

other: Minor Component (9.5-10.1% total peak area): Koc >=3548 <=3715

Type:

log Koc

Value:

>= 4.24 - <= 4.25 dimensionless

Temp.:

25 °C

Remarks on result:

other: Minor Component (7.1-8.1% total peak area): Koc >=17378 <=17783

Type:

log Koc

Value:

>= 4.89 - <= 4.91 dimensionless

Temp.:

25 °C

Remarks on result:

other: Minor Component (0.8-1.2% total peak area): Koc>=77625 <=81283

Type:

log Koc

Value:

>= 5.5 - <= 5.52 dimensionless

Temp.:

25 °C

Remarks on result:

other: Minor Component (0.3-1.3% total peak area): Koc >=316228 <=331131

Type:

log Koc

Value:

> 5.63 dimensionless

Temp.:

25 °C

Remarks on result:

other: Minor Components (0.9-4.6% individually of total peak area); all greater retention time than last eluting reference substance DDT (Log Koc = 5.63): Koc >=426580

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
- Details of fitted regression line (log k' vs. log Koc):
- Graph of regression line:
- Average retention data for test substance:

For these details see overall remarks and attachments

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the study, the log Koc value of the main component (72.7-74.4%) was 1.04-1.14 (Koc = 11-14) while the Log Koc values of the minor components (18.6-25.3%) ranged from >3.55 to >5.63 (Koc >3548 to >426580).

Executive summary:

A study was conducted to determine the adsorption / desorption of the test substance using high performance liquid chromatography (HPLC), according to OECD Guideline 121, in compliance with GLP. A range of components were found to be present in the test substance. The log Koc values for the test substance were determined to range from ≥1.04 to >5.63 (Koc ≥11 to >426580 L/kg), where the log Koc value of the main component (72.7-74.4%) was determined to be 1.04 -1.14 (Koc = 11-14) and the log Koc values of the minor components (18.6-25.3%) were >3.55 (Koc >3548). The log Koc values identified for the different components were as follows:

- log Koc: ≥1.04 - ≤1.14 (Koc ≥11.0-≤13.8) at 25°C (Principal Component (72.7-74.4% total peak area)

- log Koc: ≥3.55 - ≤3.57 (Koc ≥3548-≤3715) at 25°C (Minor Component (9.5-10.1% total peak area)

- log Koc: ≥4.24 - ≤4.25 (Koc ≥17378-≤17783) at 25°C (Minor Component (7.1-8.1% total peak area)

- log Koc: ≥4.89 - ≤4.91 (Koc ≥77625-≤81283) at 25°C (Minor Component (0.8-1.2% total peak area)

- log Koc: ≥5.5 - ≤5.52 (Koc ≥316228- ≤331131) at 25°C (Minor Component (0.3-1.3% total peak area)

- log Koc: >5.63 (Koc  >426580) at 25°C (Minor Components (0.9-4.6% individually of total peak area)

Under the study conditions, the major components of the test substance indicate a low adsorption potential while the minor components indicate a higher adsorption potential (Browne, 2013).

Description of key information

The log Koc value of the main component (72.7-74.4%) was determined to be 1.04 -1.14 (Koc = 11-14), indicating low adsorption potential, while the log Koc values of the minor components (18.6 -25.3%) ranged from >3.55 to >5.63 (Koc >3548 to >426580) indicating high adsorption potential. Although the overall test substance can be considered to be not very adsorptive, the highest log Koc value of >5.63 (Koc >426580) representing <5% components of the test substance has been considered further for risk assessment as a conservative approach.

Key value for chemical safety assessment

Koc at 20 °C:

426 580

Additional information

A study was conducted to determine the adsorption / desorption of the test substance using high performance liquid chromatography (HPLC), according to OECD Guideline 121, in compliance with GLP. A range of components were found to be present in the test substance. The log Koc values for the test substance were determined to range from ≥1.04 to >5.63 (Koc ≥11 to >426580 L/kg), where the log Koc value of the main component (72.7-74.4%) was determined to be 1.04 -1.14 (Koc = 11-14) and the log Koc values of the minor components (18.6-25.3%) were >3.55 (Koc >3548). The log Koc values identified for the different components were as follows:

- log Koc: ≥1.04 - ≤1.14 (Koc ≥11.0-≤13.8) at 25°C (Principal Component (72.7-74.4% total peak area)

- log Koc: ≥3.55 - ≤3.57 (Koc ≥3548-≤3715) at 25°C (Minor Component (9.5-10.1% total peak area)

- log Koc: ≥4.24 - ≤4.25 (Koc ≥17378-≤17783) at 25°C (Minor Component (7.1-8.1% total peak area)

- log Koc: ≥4.89 - ≤4.91 (Koc ≥77625-≤81283) at 25°C (Minor Component (0.8-1.2% total peak area)

- log Koc: ≥5.5 - ≤5.52 (Koc ≥316228- ≤331131) at 25°C (Minor Component (0.3-1.3% total peak area)

- log Koc: >5.63 (Koc  >426580) at 25°C (Minor Components (0.9-4.6% individually of total peak area)

Under the study conditions, the major components of the test substance indicate a low adsorption potential while the minor components indicate a higher adsorption potential (Browne, 2013).