Sodium 4-(4-substitutedanilino)-4-substituedbut-2-enoate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 Jul - 16 Aug 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted in 2008

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted in 1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Department of Health, London, UK

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Specific details on test material used for the study:

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:

< -3.05

Temp.:

22 °C

pH:

ca. 6.9

Any other information on results incl. tables

Preliminary estimate

Approximate solubility in n-octanol: <110 mg/L

Approximate solubility in water: >4.0E05 g/L

Approximate Pow: <2.8E-04

Log₁₀Pow: <-3.6

 

Definitive test

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

Table 3: Organic phase

Solution	Mean peak area
Standard 10.0 mg/L	4.6953E06
Standard 10.0 mg/L	4.5948E06
Organic phase matrix blank	None detected
Sample 1	4.0808E05
Sample 2	<4.0808E05
Sample 3	<4.0808E05
Sample 4	<4.0808E05
Sample 5	<4.0808E05
Sample 6	<4.0808E05

 

Table 4: Aqueous phase

Solution	Mean peak area
Standard 507 mg/L	1.1638E08
Standard 504 mg/L	1.1575E08
Aqueous phase matrix blank	None detected
Sample 1	1.1423E08
Sample 2	1.1459E08
Sample 3	1.1440E08
Sample 4	1.1368E08
Sample 5	1.1444E08
Sample 6	1.1474E08
Stock solution A	1.1325E08
Stock solution B	1.1308E08

 

The total weights [mg] and analyzed concentration [mg/L] of the respective phases are shown in the following table.

Table 5

Sample number	Total weight [mg]^1)	Organic phase		Aqueous phase			% recovery
		Analyzed concentration [mg/L]^2)	Weight [mg]^3)	Analyzed concentration [mg/L]	Weight [mg]^3)	pH
1	78.84	1.763	7.05E-02	1.989E03	79.56	6.9	101
2	78.84	<1.763	<7.05E-02	1.995E03	79.80	6.9	~101
3	106.4	<1.763	<7.05E-02	1.992E03	107.6	7.0	~101
4	106.4	<1.763	<7.05E-02	1.980E03	106.9	7.0	~101
5	53.22	<1.763	<7.05E-02	1.993E03	53.81	7.0	~101
6	53.22	<1.763	<7.05E-02	1.998E03	53.95	7.0	~101

 

pH of n-octanol saturated water: 6.3

pH of stock solution: 7.1

Temperature: 22.0 ± 0.5°C

¹⁾From analysis of the stock solution

²⁾See discussion section

³⁾From analysis of the respective phase

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

Table 6

Sample number	Organic/aqueous volume ratio	Partition coefficient	Log10Pow	Partition Coefficient
1	1:1	8.86E-04	-3.05	<8.85E-04
2		<8.84E-04	<-3.05
3	1:2	<8.85E-04	<-3.05	<8.88E-04
4		<8.90E-04	<-3.05
5	2:1	<8.85E-04	<-3.05	<8.84E-04
6		<8.82E-04	<-3.05

 

Mean Pow : <8.85E-04

log₁₀Pow : <-3.05

Pow standard deviation : 2.78E-06

 

 

Validation

The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 250 to 750 mg/L (aqueous) and 5 to 15 mg/L (organic). The results were satisfactory with a correlation coefficient (r) of 1.000 (aqueous) and 0.9985 (organic) being obtained.

 

Discussion

Due to the low concentration within the organic samples a limit of detection was applied to organic samples 2 to 6 based on organic sample 1 which had the highest concentration determined. Therefore, the overall result was a less than value.

The stock solution was prepared in n-octanol saturated water in place of water saturated n-octanol. This was due to low solubility of the test item in the organic phase. This issue has been considered to have had a negligible impact on the overall result and has been considered to be more appropriate to obtain a more realistic partition coefficient value.

 

Conclusion

The partition coefficient of the test item has been determined to be less than 8.85E-04 at 22.0 ± 0.5 °C, log₁₀Pow less than -3.05.