disodium 4,4'-bis[(prop-2-enoyl)amino][1,1'-biphenyl]-2,2'-disulfonate

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 Sep - 16 Oct 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Mainz, Germany

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

disodium 4-[(1-hydroxyprop-2-en-1-yl)amino]-4'-(prop-2-enamido)-[1,1'-biphenyl]-2,2'-disulfonate

EC Number:

812-549-0

Cas Number:

881539-89-5

Molecular formula:

C18H14N2Na2O8S2

IUPAC Name:

disodium 4-[(1-hydroxyprop-2-en-1-yl)amino]-4'-(prop-2-enamido)-[1,1'-biphenyl]-2,2'-disulfonate

Results and discussion

Water solubility

Water solubility:

521.04 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

1 330 g/L

Incubation duration:

3 d

Temp.:

20 °C

pH:

>= 6.7 - <= 6.84

Any other information on results incl. tables

FINDINGS

Measurements Preliminary Test Concentration Dependency

The data which was acquired for the preliminary test concentration dependency (flasks 1 and 2) is presented in the following table:

Preliminary test concentration dependency

Flask	Nominal load [kg/L]	Dilution factor	Peak area [mAU*min]	Measured test item concentration [g/L]
1	1.0	10000	38.427 38.161	615.32**
2	1.33	10000	4.490* 4.691* 38.302 38.672	615.74***

 The dilution was performed twice, because the measurement of the first dilution of flask 2 showed implausible results (measurements, written in italics). A dilution error was assumed, and only the second dilution was taken into account therefore.

** The recovery of the QC sample of 91.8% was taken into account.

*** The recovery of the QC sample of 92.2% was taken into account.

Nearly the same concentration was measured in both flasks: In flask 2 the determined concentration was <1% higher than in flask 1. No concentration dependency was detected.

 

Measurements during Equilibration

The data which was acquired during equilibration time (flask 1A-C, days 1 – 3) is presented in the following table:

Equilibration phase

Time [h]	Temperature [°C]	pH*	pH**	Dilution factor	Peak area [mAU*min]	Measured values [g/L]**
24.5 1A	20.0	7	6.84	10000	34.017 33.957	530.93
49 (1B)	19.6		6.70		32.599 32.354	507.27
71 (1C)	19.6		6.82		32.415 32.087	503.74

* pH, tested using indicator paper

** pH, measured using a calibrated pH meter

*** The recovery of the QC sample of 94.4% was taken into account.

As no more rising tendency was observed between samplings at 2 d and 3 d, the plateau was considered reached and sampling of flasks 2-6 was performed at day 7.

 

Measurements at Plateau

Flask	Temperature [°C]	pH*	Dilution factor	Peak area [mAU*min]	Measured values [g/L]**
2	20.4	6.82	10000	32.068 32.020	512.99
3	20.3	6.73		33.396 33.693	537.08
4	20.4	6.70		32.524 32.241	518.43
5	20.3	6.72		32.689 32.515	521.95
6	20.2	6.70		33.547 33.395	535.90

* pH at the plateau was measured using a calibrated pH meter

** The recovery of the QC sample of 92.1% was taken into account

 

Results

The measurements of flasks 1A-C and 2-6 were used for the calculation of the mean.

Flask	Concentration [g/L]	Total mean [g/L]	Total standard deviation [g/L] RSD [%]
1A	530.93	521.04	12.75 (2.4)
1B	507.27
1C	503.74
2	512.99
3	537.08
4	518.43
5	521.95
6	535.90

 

 

DISCUSSION

The solubility of AF-959 in water was determined from the measured test item concentrations in the centrifuged and filtrated test solutions.

The solubility, determined during the pre-tests, was approx. 615 g/L. According to the guideline a 5 fold excess of test item should be used for the main test. Because of the high solubility of the test item usage of 5 fold excess was not possible, because not filterable mixtures were obtained. Water was added stepwise to a mixture with nominal load 5 kg/L

during pre-test. The nominal load of 1.33 kg/L resulted in a filterable mixture during pretest.

Therefore this nominal concentration was used for the main test. Because again not filterable mixtures were obtained during the main test, water was added stepwise again.

After the final addition of water, resulting in a nominal concentration of 1.2 kg/L, all flasks were shaken for further 24 h.

Equilibration time can be considered as approximately 3 days, as the measured values after 3 d and after 2 d did not give significantly different values and no rising tendency was

present in the last three flasks (in this case flasks 1A-C).

All replicates showed good correspondence. Mean value and standard deviation of the eight flasks which were used for the calculation of water solubility at the plateau were 521.04 g/L and 12.75 g/L, respectively, corresponding to a relative standard deviation of 2.4%.

The pH value was 6.70 – 6.84 in all eight flasks, the test temperature was in the acceptable range with 19.6 – 20.4 °C over the test duration (measured in the liquid at sampling time points).

No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

 

DEVIATIONS

Deviations from the Study Plan

The following deviation from the study plan was ascertained:

¨The temperature range for storage of the test item of 2 – 8 °C was 2 times exceeded: once for 30 minutes with maximum 15.1°C and once for 60 minutes with maximum 13.7°C. This is stated as uncritical, because the deviations occurred for a short time only. No effect on the test item is expected.

Deviations from the Guideline

The following deviation from the guideline was ascertained:

¨The quantity of test substance necessary to saturate the desired volume of water is estimated from the preliminary test. About five times the quantity of test item, necessary for saturation, is used for the main test according to the guideline. Because this nominal concentration resulted in non-filterable mixtures, the highest possible nominal load was chosen for the main test. This is stated as uncritical, because saturation was achieved in the main test.