Bismuth tris(2-ethylhexanoate)

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-10-24 to 2018-11-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

yes

Remarks:

Three vessels were set up in a parallel design, each vessel was sampled several times instead of sampling one vessel at every point in time/ exclusion of O2 and CO2, under inert gas (argon)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

2008

Deviations:

yes

Remarks:

Three vessels were set up in a parallel design, each vessel was sampled several times instead of sampling one vessel at every point in time/ exclusion of O2 and CO2, under inert gas (argon)

GLP compliance:

yes (incl. QA statement)

Remarks:

signed, 2020-02-26 (inspection date: 2018-10-25)

Type of method:

flask method

Specific details on test material used for the study:

Appearance: red-brown viscous liquid
Storage Conditions: -15 °C to 40 °C

Key result

Water solubility:

31.2 µg/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

57.5 mg/L

Incubation duration:

>= 1 - <= 9 d

Temp.:

20.1 °C

pH:

>= 4.2 - <= 4.3

Remarks on result:

other: S.D: ± 8.5 µg/L

Remarks:

Calculated on a mean dissolved bismuth concentration of 10.1 ± 2.7 µg/L and a bismuth content of 32.25 %.

Water solubility:

10.1 µg/L

Conc. based on:

element (dissolved fraction)

Remarks:

Bi

Loading of aqueous phase:

57.5 other: mg test item /L

Incubation duration:

>= 1 - <= 9 d

Temp.:

20.1 °C

pH:

>= 4.2 - <= 4.3

Remarks on result:

other: S.D: ± 2.7 µg/L

Details on results:

- The mean temperature was 20.1 ± 0.1 °C
- The pH of test item solutions: 4.2 – 4.3
- The pH of method blank: 6.4 – 7.8
- The turbidity in samples from the test was always < 1 NTU indicating that filtered solutions did not contain any undissolved material.
- Analytical measurements: Subtraction of method blanks is not needed. The Bi concentrations in method blanks were below LOD / LOQ or far below concentrations in actual samples. The variations between the bismuth concentration measured were less than 15 % for the days 2 to 3. Since an increase of the bismuth concentration was observed between test day 1 and 3 the test was continued till day 9. The variation of bismuth concentration analysed at test day 8 and 9 were less than 15 % again and no increase was observed. Thus, the validity criteria as foreseen in OECD 105 and Regulation 440/2008/EC A.6 were fulfilled. All values measured during this test were used for calculation of the water solubility of bismuth tris(2-ethylhexanoate). The determination of the water solubility of Bismuth tris(2-ethylhexanoate) is based on mean dissolved Bi concentrations of sampling days 1, 2, 3, 8 and 9 and a bismuth amount of 32.25 % in the test item.
The bismuth concentration analysed in the triplicate test vessels vary between 7 and 12.5 µg/L (i.e., 7, 10.7 and 12.5 µg/L). This might be due to the viscosity of the test item and hence, due to a different surface area of bismuth tris(2-ethylhexanoate) which may result in different measured bismuth concentrations.

ICP-MS measurement with corresponding LOD/LOQ, correlation coefficient and sum of quality assurance samples and recovery.

Calibration [µg/L] – lowest and highest calibration point	Chosen isotope and gas mode	LOD [µg Bi/L]	LOQ [µg Bi/L]	Correlation coefficient	Sum of quality assurance samples	Recovery of quality assurance samples [%]
November 08, 2018; measurement of test samples and method blanks from days 1, 2, 3
0.5 – 250 (total of 11 calibration points, 11 used + blank)	^209Bi in no gas mode	0.0001	0.0002	0.9999	32	100
November 15, 2018; measurement of test samples and method blanks from days 8 and 9
0.1 – 40 (total of 10 calibration points, 10 used + blank)	^209Bi in high helium mode	0.0002	0.0006	1.0000	11	100

 

Recovery/validation data bismuth of measurement series

Element Bi	Recovery [%]	SD [%]	n (total)	n (valid)
November 08, 2018
Quality control standard (Roth) 1 µg/L	97.5	2.7	6	6
TMDA-52.4 (dilution factor 2), nominal value Bi: 11.1 µg/L – diluted 5.55 µg/L	110	1	6	6
Quality control standard (Roth) 10 µg/L	97.6	0.6	6	6
Recalibration standard 50 µg/L	102	1	6	6
Quality control standard (Roth) 100 µg/L	107	2	6	6
November 15, 2018
TMDA-52.4 (dilution factor 2), nominal value Bi: 11.1 µg/L – diluted 5.55 µg/L	92.9	2.6	3	3
Recalibration standard 10 µg/L	97.2	2.4	3	3
Quality control standard (Roth) 20 µg/L	100	2	3	3

 

Fortification of measurement series

Selected samples were fortified with known amounts of bismuth (by standard addition of commercial standard) to determine the standard recoveries of this element.

Sample	Element	Measured concentration [µg/L]	Calculated level after addition [µg/L]	Recovery [µg/L] / [%]
November 08, 2018
Vessel 3 sample a 1d (18AB3582, dilution 10-fold) 1 mL sample 4 mL 5 µg/L standard	Bi	1.02	4.20	3.92 / 93.3
Vessel 5 sample a 3d (18AB3618) 1 mL sample 4 mL 25 µg/L standard	Bi	7.42	21.5	21.8 / 101
November 15, 2018
Vessel 3 sample a 8d (18AB3648) 1 mL sample 4 mL 20 µg/L standard	Bi	9.60	17.9	17.5 / 97.8
Vessel 4 sample a 9d (18AB3660) 1 mL sample 4 mL 30 µg/L standard	Bi	12.3	26.5	25.5 / 96.3

The determination of the water solubility of Bismuth tris(2-ethylhexanoate) is based on mean dissolved Bi concentrations of sampling days 1, 2, 3, 8 and 9 and a bismuth amount of 32.25 % in the test item.

Mean Bi concentrations:

Vessel 3:       10.7 ± 1.5 µg/L

Vessel 4:       12.5 ± 1.9 µg/L

Vessel 5:        7.0 ± 0.6 µg/L

Mean:            10.1 ± 2.7 µg/L

                                             

The water solubility of Bismuth tris(2-ethylhexanoate)is:

Mean of concentration x 100 % / 32.25 %:

Vessel 3:       33.1 ± 4.6 µg/L

Vessel 4:       38.8 ± 6.0 µg/L

Vessel 5:        21.6 ± 2.0 µg/L

Mean:            31.2 ± 8.5 µg/L

Calculation of water solubility according to bismuth content and 100% purity

Sample	Bi conc. [µg/L]	Mean Bi conc. [µg/L]	SD [µg/L]	mean Bi all samples [µg/L]	SD [µg/L]	Bi in test item [%]	Calculated amount of test item dissolved on Basis of Bi [µg/L]	Mean dissolved test item [µg/L]	SD [µg/L]	mean all samples [µg/L]	SD [µg/L]
vessel 3 sample a 1d	10.2	10.7	1.5	10.1	2.7	32.25	31.59	33.1	4.6	31.2	8.5
vessel 3 sample b 1d	9.77						30.28
vessel 3 sample a 2d	12.0						37.35
vessel 3 sample b 2d	11.5						35.79
vessel 3 sample a 3d	12.8						39.80
vessel 3 sample b 3d	12.7						39.24
vessel 3 sample a 8d	9.60						29.76
vessel 3 sample b 8d	9.62						29.82
vessel 3 sample a 9d	8.41						26.07
vessel 3 sample b 9d	10.1						31.28
vessel 4 sample a 1d	10.4	12.5	1.9				32.21	38.8	6.0
vessel 4 sample b 1d	9.33						28.94
vessel 4 sample a 2d	11.7						36.29
vessel 4 sample b 2d	15.8						49.07
vessel 4 sample a 3d	14.4						44.70
vessel 4 sample b 3d	14.3						44.27
vessel 4 sample a 8d	12.2						37.97
vessel 4 sample b 8d	12.1						37.52
vessel 4 sample a 9d	12.3						38.06
vessel 4 sample b 9d	12.7						39.38
vessel 5 sample a 1d	5.95	7.0	0.6				18.44	21.6	2.0
vessel 5 sample b 1d	5.92						18.36
vessel 5 sample a 2d	7.34						22.77
vessel 5 sample b 2d	7.19						22.29
vessel 5 sample a 3d	7.42						23.00
vessel 5 sample b 3d	7.84						24.33
vessel 5 sample a 8d	7.13						22.10
vessel 5 sample b 8d	7.39						22.92
vessel 5 sample a 9d	6.70						20.78
vessel 5 sample b 9d	6.83						21.19

Conclusions:

Under the conditions of this test (under exclusion of CO2 and O2, under inert gas; flask method; loadings of 51.5, 68.5 and 52.5 mg/L ultrapure water solubility equilibrium was observed during testing (day 1 – day 9). The dissolved bismuth concentration at 20.1 ± 0.1 °C is 10.1 ± 2.7 µg/L (determined as dissolved bismuth, separated by filtration from undissolved test item). This corresponds to a water solubility of bismuth tris(2-ethylhexanoate) of 31.2 ± 8.5 µg/L, calculated on a bismuth content of 32.25 %.

Description of key information

Bismuth tris(2-ethylhexanoate) has a water solubility of 31.2 ± 8.5 µg/L at 20 °C.

Key value for chemical safety assessment

Water solubility:

31.2 µg/L

at the temperature of:

20 °C

Additional information

Under the conditions of this test (under exclusion of CO2 and O2, under inert gas; flask method; loadings of 51.5, 68.5 and 52.5 mg/L ultrapure water solubility equilibrium was observed during testing (day 1 – day 9). The dissolved bismuth concentration at 20.1 ± 0.1 °C is 10.1 ± 2.7 µg/L (determined as dissolved bismuth, separated by filtration from undissolved test item). This corresponds to a water solubility of bismuth tris(2-ethylhexanoate) of 31.2 ± 8.5 µg/L, calculated on a bismuth content of 32.25 %.