Molybdenum, bis(dibutylcarbamodithioato)di-μ-oxodioxodi-, sulfurized

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:

02 March 2016 to 25 September 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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))

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Specific details on test material used for the study:

- Purity: This substance has an Unknown or Variable composition, is a Complex reaction product, or a Biological material (UVCB).
- Description: Yellow powder
- Storage: Room temperature in the dark

Details on study design: HPLC method:

Preparation of sample solution
Test item (0.01115 g) was diluted to 100 mL with MeCN to give a concentration of 0.11 g/L.

Preparation of dead time solution
The dead time was determined by measuring the retention time of formamide (purity 99.94%, (value quoted by supplier), 889 mg/L solution in methanol:water 55:45 v/v).

Preparation of reference standard solutions
Solutions of reference standards were prepared in methanol.

Determination of retention time
The sample, dead time and reference standard solutions were injected in duplicate using the following HPLC parameters:
- HPLC System: Agilent Technologies 1100 Series
- Detector type: Ultraviolet (UV)
- Column: XSelect HSS Cyano 5 μm (150 x 4.6 mm id)
- Column temperature: 30ºC
-Mobile phase: Methanol:water (55:45 v/v), ramped to 100% after 30 mins for sample
- pH of mobile phase: 6.01
- Flow-rate: 1.0 mL/min
- Injection volume: 10 μL
- UV detector wavelength: dead time and reference standards: 210 nm, sample: 246 nm

Key result

Sample No.:

#1

Type:

log Koc

Value:

> 5.63

Key result

Sample No.:

#2

Type:

log Koc

Value:

> 5.63

Details on results (HPLC method):

Overall log10 Koc: greater than 5.63
Adsorption coefficient: greater than 4.27 x 10^5

The retention times, capacity factor and log10 Koc value determined for the sample are shown in the following table:

 

Peak	Injection	Rentention time (mins)	Capacity factor (k')	Log10 k'	Log10 Koc	Mean log10 Koc	Adsorption Coefficient
1	1	37.208	18.3	1.26	>5.63	>5.63	>4.27 x 10^5
	2	37.213	18.3	1.26	>5.63
2	1	37.797	18.7	1.27	>5.63	>5.63	>4.27 x 10^5
	2	37.792	18.6	1.27	>5.63

 

Overall log10 Koc: greater than 5.63

Adsorption coefficient: greater than 4.27 x 10⁵

Discussion

As the test item had a high affinity for the stationary phase of the column, the mobile phase was adjusted to 100% solvent shortly after the retention time of DDT to elute the sample

As the slope of the calibration curve for the reference standards showed good first order correlation and as the retention times between duplicate injections for each solution was consistent, the HPLC method was considered valid for the determination of adsorption coefficient. Based on the chromatographic data, the test item was considered to be stable during the test procedure.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the study, the adsorption coefficient (Koc) of the test item has been determined to be greater than 4.27 x 10^5, log10 Koc > 5.63.

Executive summary:

Under the conditions of the study, the adsorption coefficient of the test item has been determined to be greater than 4.27 x 10⁵, log10Koc > 5.63, using the HPLC screening method, designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.

Description of key information

Under the conditions of the study, the adsorption coefficient of the test item has been determined to be greater than 4.27 x 10⁵, log10Koc > 5.63, using the HPLC screening method, designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.