phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 12 September 2018 and 17 November 2018.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt

EC Number:

828-215-2

Cas Number:

172796-84-8

Molecular formula:

C8H12NO7P2Na

IUPAC Name:

phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt

impurity 1

Reference substance name:

4-aminophenylacetic acid

EC Number:

214-828-7

EC Name:

4-aminophenylacetic acid

Cas Number:

1197-55-3

Molecular formula:

C8H9NO2

IUPAC Name:

4-aminophenylacetic acid

impurity 2

Reference substance name:

EBP dimer

Molecular formula:

C16H22N2O12P4

IUPAC Name:

EBP dimer

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Identification: Phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt (“EBP”)
Appearance/Physical state: Beige colored powder
Batch: CHPC071917EBP
Purity: >90%
Expiry date: 01 July 2019
Storage conditions: Room temperature in the dark

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

< -3.3

Temp.:

24.3 °C

pH:

5.3

Details on results:

Preliminary Estimate
The estimated partition coefficient was less than 3.29 x 10^-4 at 22.8 ± 0.5 °C, log Pow < -3.48. The pH of the aqueous phase was 5.0.

Any other information on results incl. tables

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 1.03 mg/L	8.149 x 10^3
Standard 1.55 mg/L	4.910 x 10^4
Standard 1.52 mg/L	4.642 x 10^4
Standard 2.06 mg/L	7.467 x 10^4
Standard 3.09 mg/L	1.322 x 10^5
Organic phase matrix blank	None detected
Organic Sample 1	None detected
Organic Sample 2	None detected
Organic Sample 3	None detected
Organic Sample 4	None detected
Organic Sample 5	None detected
Organic Sample 6	None detected

Aqueous Phase

Solution	Mean Peak Area
Standard 10.3 mg/L	5.678 x 10^5
Standard 20.6 mg/L	1.323 x 10^6
Standard 30.9 mg/L	1.971 x 10^6
Standard 30.3 mg/L	1.974 x 10^6
Standard 43.4 mg/L	3.056 x 10^6
Standard 61.8 mg/L	4.095 x 10^6
Aqueous phase matrix blank	1.249 x 10^5
Aqueous Sample 1	1.920 x 10^6
Aqueous Sample 2	1.940 x 10^6
Aqueous Sample 3	1.994 x 10^6
Aqueous Sample 4	1.931 x 10^6
Aqueous Sample 5	1.958 x 10^6
Aqueous Sample 6	1.974 x 10^6
Stock solution A	1.927 x 10^6
Stock solution B	1.976 x 10^6

The analyzed concentration (mg/L) and test item weight (mg) of the respective phases are shown in the following table:

Flask	Total Weight (mg)*	Organic Phase		Aqueous Phase			% Recovery
		Analyzed Concentration (mg/L)	Weight (mg)†	Analyzed Concentration (mg/L)	Weight (mg)†	pH
1	145	<1.5	<3.6 x 10^-2	2.98 x 10^3	143	5.2	~98.5
2	157	<1.5	<3.9 x 10^-2	3.01 x 10^3	157	5.3	~99.5
3	121	<1.5	<6.0 x 10^-2	3.09 x 10^3	124	5.3	~102
4	84.7	<1.5	<4.2 x 10^-2	3.00 x 10^3	83.9	5.3	~99.1
5	72.6	<1.5	<7.2 x 10^-2	3.03 x 10^3	72.8	5.3	~100
6	90.8	<1.5	<9.0 x 10^-2	3.06 x 10^3	91.7	5.3	~101

pH of n-octanol saturated water:       7.0
pH of stock solution:                         5.0
Temperature:                                     24.3 ± 0.5°C

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

Flask	Organic/Aqueous Volume Ratio	Partition Coefficient	Log10Pow	Overall Partition Coefficient
1	1:2	<5.04 x 10^-4	<-3.30	<5.04 x 10^-4
2		<4.99 x 10^-4	<-3.30
3	1:1	<4.86 x 10^-4	<-3.31	<5.01 x 10^-4
4		<5.01 x 10^-4	<-3.30
5	2:1	<4.94 x 10^-4	<-3.31	<4.94 x 10^-4
6		<4.91 x 10^-4	<-3.31

Overall P_ow:<5.04 x 10^-4                 Log₁₀ P_ow:<-3.30

* From analysis of the stock solution

† From analysis of the respective phase

Applicant's summary and conclusion

Conclusions:

The partition coefficient of the test item at pH 5.3 ± 0.1 has been determined to be less than 5.04 x 10^-4 at 24.3 ± 0.5 °C, log10 Pow <-3.30.

Executive summary:

Partition Coefficient (n-Octanol/Water). Less than 5.0 x 10^-4at 24.3 ± 0.5 °C, log₁₀P_ow <-3.3, at pH 5.3 ± 0.1, using the shake-flask method, designed to be compatible with Method A.8 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.