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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:
OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))
Principles of method if other than guideline:
To determine Adsorption coefficient (KOC) on soil and on sewage sludge of the 4-Nonylphenol, branched,ethoxylated (CAS No. 127087-87-0) using HPLC.
GLP compliance:
no
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Specific details on test material used for the study:
- EC name: 4-Nonylphenol, branched, ethoxylated
- Name of test material (as cited in study report): Nonylphenol ethoxylates
- Molecular formula: C17H28O2
- Molecular weight: 264.409 g/mol
- Substance type: Organic
- Physical state: Liquid

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:098K0139V

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:Ambient Temp (23 to 27 °C) (Keep container tightly closed in a dry & wellventilated place. Store in cool place. Do not expose to air, light & moisture.)
- Stability under test conditions:Stable in recommended storage conditions

Radiolabelling:
not specified
Test temperature:
25°C
Details on study design: HPLC method:
The solutions of the test substance and reference substances were prepared in the mobile phase. Each of the reference substance and test substance were analysed by HPLC at 210 nm.
After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed.
Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor.
Operating Conditions:
HPLC Model No. : Agilent Technologies,1260 Infinity
Flow Rate : 1.0 mL/min
Column : ZORBAX Eclipse Plus C18, 4.6×100mm, 3.5 μm
Mobile phase : Acetonitrile: water (55:45)
Temperature : 25°C
Detector : Diode Array Detector @210nm
Injector : Autosampler
Injector volume : 10μl
Data Acquisition software : ChemStationOpen lab Control Panel
Details on test conditions:
A test item solution was prepared by accurately weighing 5 μL of test item and diluted with methanol up to 10 ml.Thus, the test solution concentration was 524.5 mg/l. The pH of test substance was 7.5.
Key result
Type:
log Koc
Value:
2.631 dimensionless
pH:
7.5
Temp.:
25 °C
Remarks on result:
other: reported as 2.6311 ± 0.0001
Transformation products:
not specified

Test substance

4-Nonylphenol, branched, ethoxylated

K

Log k

Log Koc

by Generalized Calibration

Graph

Mean of Log Koc ± S.D.

tR1

4.267

3.40805

0.53250

2.63128

2.6311 ± 0.0001

tR2

4.266

3.40702

0.53237

2.63107

Validity criteria fulfilled:
yes
Conclusions:
The Adsorption Coefficient of test substance 4-Nonylphenol, branched, ethoxylated (CAS No. 127087-87-0)was determined as per the HPLC method (OECD Guideline-121). The log Koc value was found to be 2.6311 ± 0.0001 at 25°C.
Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge 4-Nonylphenol, branched, ethoxylated(CAS No.127087-87-0) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The chosen reference substances were having Koc value ranging from 1.239 to 2.47. The Log Koc value was found to be 2.6311 ± 0.0001 at 25°C.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge 4-Nonylphenol, branched, ethoxylated(CAS No.127087-87-0) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The chosen reference substances were having Koc value ranging from 1.239 to 2.47. The Log Koc value was found to be 2.6311 ± 0.0001 at 25°C.

Key value for chemical safety assessment

Koc at 20 °C:
427.66

Additional information

Four studies for adsorption in soil/sediment endpoint including experimental and valid predicted model data of test chemical 4-Nonylphenol, branched, ethoxylated (Cas no. 127087-87-0) with relevant read across chemicals which is 90-80 % structurally similar to target were reviewed as follows:

 

First study from experimental report of UERL (2017) indicates that the adsorption coefficient Koc in soil and in sewage sludge 4-Nonylphenol, branched, ethoxylated(CAS No.127087-87-0) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The chosen reference substances were having Koc value ranging from 1.239 to 2.47. The Log Koc value was determined to be 2.6311 ± 0.0001 at 25°C.

And supporting data of target indicate the Soil Adsorption Coefficient i.e Koc value of 4-Nonylphenol, branched, ethoxylated was estimated using EPI suite KOCWIN Program (v2.00) as Koc 1035 L/kg(log Koc=3.014) by means of MCI method at 25 deg.C. This Koc value indicates that the substance 4-Nonylphenol, branched, ethoxylated has a moderate sorption to soil and sediment and therefore have slow migration potential to groundwater.

 

Whereas experiment result (HSDB database by US EPA) for read across chemical 4-Nonylphenol, ethoxylated (Cas no. 26027-38-3) indicate that using a structure estimation method based on molecular connectivity indices, the Koc of 4-Nonylphenol, ethoxylated can be estimated to be 1300 This estimated Koc value suggests that 4-Nonylphenol, ethoxylated is expected to have low mobility in soil.

 

Study from another read across substance Nonylphenol, ethoxylated (Cas no. 9016-45-9) suggest that the Adsorption of nonylphenol polyethoxylates is dependent upon the number of ethoxylate units present; Sludge adsorption was greatest for nonylphenol (44-48% of the added compound adsorbed) followed by nonylphenol ethoxylate (n=1) (14-15% of the added compound adsorbed to sludge), and nonylphenol diethoxylate (67% of the added compound adsorbed to sludge). Adsorption of nonylphenyl ethoxylate (n=6) to sediment was dependent on the organic matter concentration. A Koc of 6.1 was measured in sediment. Polyethyleneglycol nonylphenyl ether (n=13) was observed to Kd values ranging from 450-1460 L/kg in sediment, 230-590 L/kg in sediment without organic carbon, 25-92L/kg in silica, and 12000-13000 L/kg in sludge, suggesting strong sorption may occur to the solid phase in soil.

 

Thus all above studies for target and read across reports from authorative databases arrive at a conclusion as the test substance 4-Nonylphenol, branched, ethoxylated (Cas no. 127087-87-0) has low mobility in soil/sediment compartment.

[LogKoc: 2.6311]