N4,N4'-hexane-1,6-diylbis[N-butyl-6-chloro-N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)-1,3,5-triazine-2,4-diamine]

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

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))

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material:
190701
- Expiration date of the lot/batch:
24 July 2021
- Purity:
>90%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
Room Temperature
- Stability under storage conditions:
Stable

Radiolabelling:

no

Test temperature:

Room temperature

Details on study design: HPLC method:

INSTRUMENT HPLC-DAD (Agilent 1100)
COLUMN Luna CN (150mmx4.6mmx5.0um)
COLUMN TEMPERATURE 25°C
AUTOSAMPLER TEMP 20°C
WAVELENGTH 210 nm (scan 190-400)
MOBILE PHASE A% = 45%10 mM citrate buffer at pH 6.0
B% = 55% methanol
FLOW 1.0 mL/min
MOBILE PHASE Signal, Bw (nm): 210, 4
Reference, Bw (nm): 360, 100
INJECTION VOLUME 5.0 pl
RUN TIME 8 min

Details on test conditions:

TEST CONDITIONS
- Buffer:
About 5.88 g of Sodium citrate tribasic dihydrate was quantitatively weighed and transferred into a beaker contained about 1500 mL of HP water.
- pH:
The pH was measured and corrected with HCI 1M until the value was 6. The solution was brought to 2000 mL with HP water.
- Suspended solids concentration:
not applicable


TEST SYSTEM
- Type, size and further details on reaction vessel:
not applicable
- Water filtered (i.e. yes/no; type of size of filter used, if any):
not applicable
- Amount of soil/sediment/sludge and water per treatment (if simulation test):
not applicable
- Soil/sediment/sludge-water ratio (if simulation test):
not applicable
- Number of reaction vessels/concentration:
13
- Measuring equipment:
Agilent Series 1100 High Performance Liquid Chromatograph (HPLC) equipped with an Agilent Series 1100 variable wavelength UV-DAD detector, a binary pump, an autosampler and a data station with Chemstation - internal code LV-B1162.
- Test performed in closed vessels due to significant volatility of test substance:
not applicable
- Test performed in open system:
not applicable
- Method of preparation of test solution:
Mobile Phase/Solvent Mixture
450 mL of Citrate Buffer pH 6 was mixed with 550 mL of Methanol.

Sodium Nitrate stock solution (conc. = 1.0 mg/mL)
About 50 mg of Sodium Nitrate reference standard was exactly weighed into a 50 mL volumetric flask and brought to volume with Methanol (Solution A).
Sodium Nitrate solution (conc. = 0.025 mg/mL)
0.4 mL of Sodium Nitrate stock solution was diluted to 20 mL with solvent mixture.
Benzamide stock solution (conc. = 1.0 mg/mL)
About 50 mg of Benzamide reference standard was exactly weighed into a 50 mL volumetric flask and brought to volume with Methanol (Solution B).
Benzamide solution (conc. = 0.025 mg/mL)
0.5 mL of Benzamide stock solution was diluted to 20 mL with solvent mixture
Acetanilide stock solution (conc. = 1.0 mg/mL)
About 50 mg of Acetanilide reference standard was exactly weighed into a 50 mL volumetric flask and brought to volume with Methanol (Solution C).
Acetanilide solution (conc. = 0.015 maq/mL)
0.3 mL of Acetanilide stock solution was diluted to 20 mL with solvent mixture.
2,5-Dichloroaniline stock solution (conc. = 1.0 mg/mL)
About 50 mg of 2,5-Dichloroaniline reference standard was exactly weighed into a 50 mL volumetric flask and brought to volume with Methanol (Solution D).
2,5-Dichloroaniline solution (conc. = 0.0075 maq/mL)
0.15 mL of 2,5-Dichloroaniline stock solution was diluted to 20 mL with solvent mixture.
Benzoic acid Phenylester stock solution (conc. = 1.0 mg/mL)
About 50 mg of Benzoic acid Phenylester reference standard was exactly weighed into a 50 mL volumetric flask and brought to volume with Methanol (Solution E).
Benzoic acid Phenylester solution (conc. = 0.025 mg/mL)
0.5 mL of Benzoic acid Phenylester stock solution was diluted to 20 mL with solvent mixture.
Fenthion stock solution (conc. = 1.0 mg/mL)
About 10 mg of Fenthion reference standard was exactly weighed into a 10 mL volumetric flask and brought to volume with Methanol (Solution F).
Fenthion solution (conc. = 0.025 mg/mL)
0.5 mL of Fenthion stock solution was diluted to 20 mL with solvent mixture.
Phenanthrene stock solution (conc. = 1.0 mg/mL)
About 50 mg of Phenanthrene reference standard was exactly weighed into a 50 mL volumetric flask and brought to volume with Methanol (Solution G).
Phenanthrene solution (conc. = 0.025 ma/mL)
0.25 mL of Phenanthrene stock solution was diluted to 20 mL with solvent mixture.

The solution was brought to volume with solvent mixture.

Test item stock solution (conc. = 1 mg/mL - double preparation)
About 50 mg of test item was exactly weighed into a 50 mL volumetric flask and brought to volume with Methanol.
Test item solution + sodium nitrate (conc. = 0.2 mg/mL - double preparation)
2 mL of this solution and 0.5 mL of solution A was diluted to 10 mL with solvent mixture.
Test item solution (conc. = 0.2 mg/mL)
2 mL of this solution was diluted to 10 mL with solvent mixture.

- Are the residues from the adsorption phase used for desorption:
no

Key result

Sample No.:

#1

Type:

log Koc

Value:

> 4.09 dimensionless

pH:

6

Temp.:

20 °C

Matrix:

Soils

Remarks on result:

not determinable because of methodological limitations

Key result

Sample No.:

#2

Type:

log Koc

Value:

> 4.35 dimensionless

pH:

6

Temp.:

20 °C

Matrix:

sewage sludge

Remarks on result:

not determinable because of methodological limitations

Details on results (HPLC method):

The results are reported below :
The calibration reference standards, consist of 6 reference substances of known log Kcc: Acetanilide, Benzamide, 2,5-Dichloroaniline, Benzoic acid Phenylester, Fenthion and Phenanthrene.
The standards chosen had a log Ko, for soils between 1.26 — 4.09 and a log Ko, for sewage sludge between 1.52 — 4.35.

Calibration line of the reference standardsfor soils
Linear Correlation:
slope 3,9830
intercept 2,1717
correlation 0,9771
R2 0,9547

Calibration line of the reference standards for sewage sludge
Linear Correlation:
slope 4,1077
intercept 2,4246
correlation 0,9822
R2 0,9647

Sample peak didn’t elute in the conditions prescribed by OECD 121 and log Koc cannot be estimate. It can be supposed that log K,, on soils and sewage sludge are higher than logkK,, on soils and sewage sludge of phenanthrene (the most retained standard).

Transformation products:

no

Validity criteria fulfilled:

yes

Executive summary:

The aim of the study was to estimate Adsorption Coefficient (Koc) on Soil and on Sewage Sludge by high performanceliquid chromatography (HPLC) method according to OECD 121 oftest item “N4,N4'- hexane-1 ,6-diylbis[N-butyl-6-chloro-N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)-1,3,5-triazine-2,4 diamine].

The adsorption coefficient is defined as the ratio between the concentration of the substance in the soil/sludge and the concentration of the substance in the aqueous phase at adsorption equilibrium. The adsorption coefficient normalised to the organic carbon content of the soil (Koc) is a useful indicator of the binding capacity of a chemical on organic matter of soil and sewage sludge and allows comparisons to be made between different chemicals.

The adsorption coefficient was estimated by the HPLC method .

The Test Item didn’t elute with the chromatographic conditions prescribed by the guidelines OECD 121 (methanol/0.01M buffer citrate pH 6.0, 55/45%v/v) and it was retained in the column, so it cannot be estimated the logKoc of the test item.

Since the most retained reference standard, used in the calibration curve, was phenanthrene (logKoc on soils: 4.09 - logKoc on sewage sludge: 4.35), it can be supposed that, at pH 6, logKoc on soils for the test item is higher than 4.09 and logKoc on sewage sludge is higher than 4.35.

Description of key information

The adsorption coefficient was estimated by the HPLC method .

The Test Item didn’t elute with the chromatographic conditions prescribed by the guidelines OECD 121 (methanol/0.01M buffer citrate pH 6.0, 55/45%v/v) and it was retained in the column, so it cannot be estimated the logKoc of the test item.

Since the most retained reference standard, used in the calibration curve, was phenanthrene (logKoc on soils: 4.09 - logKoc on sewage sludge: 4.35), it can be supposedthat, at pH 6, logKoc on soils for the test item is higher than 4.09 and logKoc on sewage sludge is higher than 4.35.

Key value for chemical safety assessment

Koc at 20 °C:

4.35