bis(O,O-2-ethylhexyl-thiophosphoryl)polysulfide

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-05-11 - 2017-10-19 (experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Remarks:

Water solubility

Reason / purpose for cross-reference:

reference to same study

Remarks:

Partition coefficient

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

EC Guideline C.19. Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC). May 31, 2008

Deviations:

no

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))

Version / remarks:

OECD Guideline 121. Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC). January 22, 2001.

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EC Technical Guidance Document on Risk Assessment Part III Chapter 4.3: Use of (Quantitative) Structure Activity Relationships ((Q)SARs) - Soil and Sediment Sorption. 2003.

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

other: The dual composition of a cyanopropyl stationary phase, having polar and non-polar sites allows for interaction of polar and non-polar groups of a molecule in a similar way as is the case for organic matter in soil or sewage sludge matrices.

Specific details on test material used for the study:

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

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: In refrigerator (2-8°C)

Radiolabelling:

no

Test temperature:

35°C

Details on study design: HPLC method:

EQUIPMENT
Analytical Conditions
Instrument: Acquity UPLC system (Waters, Milford, MA, USA)
Detector: Acquity UPLC PDA detector (Waters)
Column: Acquity UPLC HSS Cyano, 100 mm * 2.1 mm i.d., dp = 1.8 µm (Waters)
Column temperature: 35°C ± 1°C
Injection volume: 5 µL
UV detection: 210 nm (unretained compound, reference substance and test solution); 254 nm (test solution)

MOBILE PHASES
- Type:
Solvent A: 100% isopropyl alcohol
Solvent B: 100% water
Solvent C: 100% methanol
- Solutes for dissolving test and reference substances:
Solution of the Unretained Compound: A 5 g/L stock solution of formamide (99.2%, [75-12-7], Alfa Aesar, Karlsruhe, Germany) in methanol was used. The stock solution was diluted to obtain an end solution of 55/45 (v/v) methanol/water. The formamide blank solution was 55/45 (v/v) methanol/water.
Reference Substance Solution: Stock solutions of the reference substances at concentrations of approximately 1 g/L in methanol were used. The stock solutions were diluted to obtain an end solution of 55/45 (v/v) methanol/water.
The blank solution for the mixture of reference substances was 55/45 (v/v) methanol/water.

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

REFERENCE SUBSTANCES
- Identity:
Reference substance Purity CAS number
Acetanilide 99.8% 103-84-4
Monuron 99.9% 150-68-5
2,5-Dichloroaniline 99.9% 95-82-9
Naphthalene 99.5% 91-20-3
Benzoic acid phenylester 99.9% 93-99-2
Fenthion 97.5% 55-38-9
Phenanthrene 98.1% 85-01-8
4,4’-DDT 98.7% 50-29-3

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 5µl of a 100 mg/L solution

REPETITIONS
- Number of determinations: Reference substance and test item solutions were injected in duplicate. Blank solutions were analyzed by single injection.

EVALUATION
- Calculation of capacity factors k': k' = (tr - t0) / t0, where:
tr = retention time
t0 = mean column dead time
- Determination of the log Koc value: Calibration curve: logk' = a * logKoc + b, where:
a = slope
b = intercept

Type:

log Koc

Value:

4.23 dimensionless

Temp.:

35 °C

Remarks on result:

other: Test item – peak 1 (minor constituent)

Remarks:

neutral pH

Type:

log Koc

Value:

4.28 dimensionless

Temp.:

35 °C

Remarks on result:

other: Test item – peak 2 (minor constituent)

Remarks:

neutral pH

Key result

Type:

log Koc

Value:

> 5.63 dimensionless

Temp.:

35 °C

Remarks on result:

other: Test item – peak 3 - 13 (major constituent)

Remarks:

neutral pH

Details on results (HPLC method):

- Retention times of reference substances used for calibration: see table below
- Average retention data for test substance: see table below

Validity criteria fulfilled:

yes

Conclusions:

The study was performed according to OECD TG 121 under GLP on the substance to be registered itself, the test procedure is well documented and therefore reliability of Klimisch 1 has been assigned. The analytical method was properly established. The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of the test item.
The Koc and log Koc values of the test item at neutral pH were:
Koc log Koc
Test item – peak 1 1.7 x 10E4 4.23
Test item – peak 2 1.9 x 10E4 4.28
Test item – peak 3 - 13 > 4.3 x 10E5 > 5.63

Executive summary:

The Adsorption coefficient of the test item was determined according to EC C.19 and OECD 121 under GLP via HPLC method based on soil-adsorption-reference data to log K_oc: > 5.63 (major component).

Description of key information

Adsorption coefficient: log Koc > 5.63, Koc > 4.3 x E5 (major component)(EC C.19, OECD 121, GLP, HPLC method)

Key value for chemical safety assessment

Koc at 20 °C:

450 000

Additional information

[LogKoc: 5.65]