Barbital sodium

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Dec. 2018 - Jan. 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes

Type of method:

flask method

Key result

Water solubility:

181.6 kg/m³

Conc. based on:

test mat. (dissolved fraction)

Incubation duration:

4 d

Temp.:

20 °C

pH:

>= 9.97 - <= 10.1

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicating that no colloidal dispersed particles or micelles are present.

The data which was acquired during equilibration time is presented in the following table:

Equilibration

Day	Temperature [°C]	pH*	Area 1 (diluted sample)[mAU*min]	Area 2 (diluted sample)[mAU*min]	Measured Concen-tration 1 [mg/L]	Measured Concentration 2 [mg/L]	Concentration test item [g/L]**	Difference to previous sample
1	19.7	11	21.6035	22.0373	44.37	45.29	179.3	-
2	20.1	11	22.0405	22.0238	45.29	45.26	181.1	1.0%
3	19.6	11	21.6070	21.2537	44.38	43.64	176.0	-2.8%
Blank	-	-	0.9115	-	< 10 mg/L	-	-	-

*pH of the filtrated test solution was measured with pH paper

**Dilution factor 4000 is taken into account.

The final measurement was performed for organizational reasons on day 4. All measurements of the day 4 were included in the calculation of the mean.

 Measurements used for Calculation of Solubility

Day	Flask	Concentration [g/L]	Total Mean [g/L]	Total Standard Deviation [g/L] (RSD* [%])
4	2	181.8	181.6	4.7 (2.6)
4	3	174.0
4	4	184.7
4	5	181.4
4	6	186.1

*RSD = relative standard deviation

 

At the plateau, the concentration of Barbital Sodium in water had reached

181.6 ± 4.7 g/L at 20.0 ± 0.2 °C

= 181.6 ± 4.7  kg/m3 (SI units).

The equilibration time can be considered as 1 day, as the values which were measured on the following consecutive days did not give significantly different values.

All replicates showed good correspondence. Standard deviation of the samples which were used for the calculation of water solubility (at plateau) was 4.7 g/L, corresponding to a relative standard deviation of 2.6 %.

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

Conclusions:

The concentration of Barbital Sodium in water was determined in a test according to OECD 105 resp. EU A.6 to be 181.6 ± 4.7 g/L at 20.0 ± 0.2 °C and pH 9.97-10.1.

Description of key information

The concentration of Barbital Sodium in water was determined in a test according to OECD 105 resp. EU A.6 to be 181.6 ± 4.7  g/L at 20.0 ± 0.2 °C and pH 9.97-10.1.

Key value for chemical safety assessment

Water solubility:

181.6 g/L

at the temperature of:

20 °C