Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-[2-[bis(phosphonomethyl)amino]methylethyl]-.omega.-[2-[bis(phosphonomethyl)amino]methylethoxy]-, sodium salt (1:?)

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Testing was conducted between 15 June 2011 and 20 December 2011.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted 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. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

-4.33

Temp.:

22 °C

pH:

5.1

Details on results:

See any other information on results incl. tables section.

Preliminary estimate

Approximate solubility in n-octanol:        1.10 x 10^-2% w/w
Approximate solubility in water    :          61.8% w/w
Approximate P_ow  :           1.78 x 10^-4
Log₁₀P_ow :          

-3.75

Definitive test

The mean peak areas obtained for the standard, stock and sample solutions are shown in the following two tables:

Organic Phase

Solution	Mean Peak Area
Standard 1.08 x 10^3mg/l	7.280 x 10^8
Standard 860 mg/l	4.938 x 10^8
Standard 645 mg/l	3.331 x 10^8
Standard 662 mg/l	3.132 x 10^8
Standard 430 mg/l	1.963 x 10^8
Standard 215 mg/l	6.058 x 10^7
Standard 108 mg/l	2.366 x 10^7

  Continued – Organic Phase

Solution	Mean Peak Area
Organic phase matrix blank	0.000
Sample 1	1.100 x 10^6
Sample 2	1.240 x 10^6
Sample 3	1.286 x 10^6
Sample 4	1.729 x 10^6
Sample 5	1.747 x 10^6
Sample 6	1.205 x 10^6

Aqueous Phase

Solution	Mean Peak Area
Standard 1.04 x 10^3mg/l	5.646 x 10^8
Standard 833 mg/l	4.196 x 10^8
Standard 625 mg/l	2.906 x 10^8
Standard 631 mg/l	3.028 x 10^8
Standard 416 mg/l	1.743 x 10^8
Standard 208 mg/l	6.434 x 10^7
Standard 104 mg/l	2.336 x 10^7
Aqueous phase matrix blank	0.000
Sample 1	2.803 x 10^8
Sample 2	2.690 x 10^8
Sample 3	2.818 x 10^8
Sample 4	2.697 x 10^8
Sample 5	2.892 x 10^8
Sample 6	2.834 x 10^8
Stock solution A	2.606 x 10^8
Stock solution B	2.627 x 10^8

 

Please see attached background material for Calibration Curves.

The total weights (mg) and analysed concentration (mg/l) of the respective phases are shown in the following table:

Sample Number	Total Weight (mg)*	Organic Phase		Aqueous Phase
		Analysed Concentration (mg/l)	Weight (mg)†	Analysed Concentration (mg/l)	Weight (mg)†	pH
1	301	0.233	0.121	6.12 x 10^3	318	5.0
2	371	0.263	0.168	5.92 x 10^3	379	5.0
3	168	0.240	0.138	6.14 x 10^3	178	5.1
4	174	0.366	0.217	5.94 x 10^3	178	5.1
5	98.5	0.370	0.254	6.27 x 10^3	107	5.1
6	92.7	0.256	0.159	6.17 x 10^3	98.7	5.1

*From analysis of the stock solution

†From analysis of the respective phase

pH of n-octanol saturated water:  6.3
pH of stock solution:                     5.1
Temperature:                               22.0 ± 0.5°C

The partition coefficient determined for each sample is shown in the following table:

Sample Number	Organic/Aqueous Volume Ratio (nominal)	Partition Coefficient	Log10Pow	Mean Partition Coefficient
1	10:1	3.81 x 10^-5	-4.42	4.13 x 10^-5
2		4.44 x 10^-5	-4.35
3	20:1	3.90 x 10^-5	-4.41	5.03 x 10^-5
4		6.16 x 10^-5	-4.21
5	40:1	5.90 x 10^-5	-4.23	5.02 x 10^-5
6		4.14 x 10^-5	-4.38

Mean P_ow : 4.73 x 10^-5        log₁₀P_ow: -4.33        P_ow standard deviation : 1.03 x 10^-5

Validation

Recovery of analysis of the sample procedure was assessed and proved adequate for the test.

At a nominal concentration of 0.1 mg/l, a mean percentage recovery of 114% was obtained (range 106 to 120%).

Concentrations have not been corrected for recovery of analysis.

Conclusions:

The partition coefficient of the test item has been determined to be 4.73E-05 at 22.0 ± 0.5°C, log10 Pow, -4.33.

Executive summary:

Determination of partition coefficient was carried out using the shake-flask Method, designed to be compatible with Method A8 Partition Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 107 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

The partition coefficient of the test item was determined to be 4.73 x 10^-5at 22.0 ± 0.5°C (log P_ow, -4.33).

Description of key information

The partition coefficient of the test item has been determined to be 4.73 x 10^-5 (log Pow, -4.33).

Key value for chemical safety assessment

Log Kow (Log Pow):

-4.33

at the temperature of:

22 °C

Additional information

4.73 x 10^-5 , log₁₀ Pow -4.33 at 22.0 ± 0.5°C, using the flask method, designed to be compatible with Method A8 Partition Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 107 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.