Tributyl-2-thiourea

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 22 March 2017 to 01 August 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to other study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 09 June 2017 to 25 July 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes

Type of method:

OECD harmonised ring method

Key result

Surface tension:

56.3 mN/m

Temp.:

20 °C

Remarks on result:

other: Conc.= 90% of test item saturation solubility

Table: Surface tension measurements

 

Measurement	Time passed after transfer test solution to test vessel [minutes]	Surface tension (mN/m)
		individual	mean (1)	mean (2)
1	15	58.1	56.7	56.3
2	16	56.8
3	17	56.6
4	18	56.6
5	20	56.5
6	21	56.8

(1) Mean calculated from measurements 2 to 6, after equilibrium was reached.

(2) Mean multiplied by the calibration factor and Harkins-Jordan corrected.

Conclusions:

The surface tension of an aqueous substance solution at 90% of its saturation solubility was determined to be 56.3 mN/m (at 20°C).

Executive summary:

Using the OECD harmonized ring method in a GLP study according to EC A.5 and OECD 115, the surface tension of an aqueous substance solution at 90% of its saturation solubility was determined to be 56.3 mN/m (at 20°C). According to the EC A.5 guideline the substance is surface active.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Version / remarks:

2008

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

1995

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)

Version / remarks:

1996

Deviations:

no

Principles of method if other than guideline:

In course of the performance of the shake flask method, no indication of surface activity such as foam formation was observed. Furthermore, the measured partition coefficient was in good agreement with the partition coefficient predicted by the Rekker calculation method. Therefore, the partition coefficient study was considered not affected by the slight surface activity of the test item.

GLP compliance:

yes

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Tributyl-2-thiourea

EC Number:

219-350-2

EC Name:

Tributyl-2-thiourea

Cas Number:

2422-88-0

Molecular formula:

C13H28N2S

IUPAC Name:

1,1,3-tributylthiourea

Test material form:

liquid

Details on test material:

- Name of test material (as cited in study report): Tri butyl thiourea
- Appearance: Clear pale to medium brown liquid
- Storage conditions: At room temperature

Study design

Analytical method:

liquid chromatography

Results and discussion

Partition coefficient

Partition coefficient 1

Key result

Type:

log Pow

Partition coefficient:

4

Temp.:

20 °C

pH:

>= 6.7 - <= 6.9

Partition coefficient 2

Key result

Type:

Pow

Partition coefficient:

9 900

Temp.:

20 °C

pH:

>= 6.7 - <= 6.9

Details on results:

- Concentration analysed in the stock solution: 0.100 g/L.
- Nominal quantity of the substance in each test sample: 0.201 mg.
- Recovery (range) for the test samples: 107% - 111%.
- The log Pow values were within the criterion range of ± 0.3 log units (see table below)

Any other information on results incl. tables

Table: Shake-flask results

 

Ratio n-octanol : water [v:v]	Analyzed concentration		Pow		log Pow	pH
	n-octanol [g/L]	water [g/L]	individual	Mean
1:1	0.0358	3.22E-6	1.1E4	8.8E3	4.0	6.8
	0.0365	5.59E-6	6.5E3		3.8	6.8
1:2	0.0545	4.80E-6	1.1E4	1.1E4	4.1	6.9
	0.0559	5.30E-6	1.1E4		4.0	6.8
2:1	0.0272	2.68E-6	1.0E4	1.0E4	4.0	6.7
	0.0273	2.78E-6	9.8E3		4.0	6.8
Mean			9.9E3		4.0
Standard deviation			1.7E3

 

 

Applicant's summary and conclusion

Conclusions:

The log Pow of the substance at neutral pH and 20°C was determined to be 4.0.

Executive summary:

The log Pow of the substance was determined using the shake-flask method in a GLP study according to EC A.8, OECD 107 and OPPTS 830.7550. Quantitative analysis was performed by LC-MS-MS. The partition coefficient was determined at neutral pH and 20°C, obtaining a Pow of 9.9E03 and a standard deviation of 1.7E3. The log Pow of the substance at neutral pH and 20°C was determined to be 4.0.