Tributylphosphine

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2017-03-08 - 2017-09-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Version / remarks:

EC Guideline A.24. Partition Coefficient (n-octanol/water), High Performance Liquid Chromatography (HPLC) Method. March 1, 2016.
EPA Product Properties Test Guideline OPPTS 830.7570: Partition Coefficient (n-octanol/water), Estimation by Liquid Chromatography. August 1996.

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Tributylphosphine

EC Number:

213-651-2

EC Name:

Tributylphosphine

Cas Number:

998-40-3

Molecular formula:

C12H27P

IUPAC Name:

tributylphosphane

Test material form:

not specified

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Partition coefficient 1

Type:

log Pow

Partition coefficient:

6.8

Remarks on result:

other: Calculated

Partition coefficient 2

Type:

log Pow

Partition coefficient:

3.1

Temp.:

30 °C

pH:

7

Remarks on result:

other: Major hydrolysis product

Partition coefficient 3

Type:

log Pow

Partition coefficient:

3

Temp.:

30 °C

pH:

11

Remarks on result:

other: Major hydrolysis product

Any other information on results incl. tables

The calculation method was used for a preliminary estimation of the Pow of the test item. Calculation was performed using the Rekker calculation method (PrologP 6.0, module in Pallas 3.0, CompuDrug International, San Francisco, CA, USA). The Pow of the test item was calculated to be 5.9 x 10e6 (log Pow 6.8) using the Rekker calculation method. Based on the calculation it was decided to perform the HPLC method for the determination of the Pow of the test item.

The HPLC P_ow and log P_ow values of the test item at pH 7 and pH 11 were:

	pH 7			pH 11
	Pow	log Pow	Peak area (%)	Pow	log Pow	Peak area (%)
Test item – peak 1	3.8x10^1	1.6	5.6	n.a.	n.a.	5.4
Test item – peak 2	2.2x10^2	2.3	7.4	2.4x10^1	1.4	5.0
Test item – peak 3	1.2x10^3	3.1	71	1.8x10^2	2.3	10
Test item – peak 4	7.9x10^3	3.9	2.4	9.9x10^2	3.0	62
Test item – peak 5	1.5x10^7	> 6.5	13	7.4x10^3	3.9	2.2
Test item – peak 6	-	-	-		> 6.5	15

 

Applicant's summary and conclusion

Conclusions:

The Pow of the test item was calculated to be 5.9 x 10e6 (log Pow 6.8) using the Rekker calculation method. Using the HPLC method, the log Pow is >= 3.1 for 86.4% of the analysed substances.

Executive summary:

Tributylphosphine oxidizes readily in contact with water. The Pow of the test item was calculated to be 5.9 x 10e6 (log Pow 6.8) using the Rekker calculation method.

The OECD 117 test measured 6 peaks in the HPLC analysis corresponding to 6 different hydrolysis products (no analytical monitoring could be done to determine what these products were). The log Pow measured for the major component (largest peak area measured) was 3.1 at pH 7 and 3.0 at pH 11. When taking into account the peaks from the components above that indicates that in total the log Pow is >= 3.1 for 86.4% of the analysed substances.