Lithium neodecanoate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-05-14 to 2018-05-25

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:

Two vessels will be set up in a parallel design, each vessel will be 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:

Two vessels will be set up in a parallel design, each vessel will be 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 2016-05-31

Type of method:

flask method

Specific details on test material used for the study:

Storage conditions: Keep container tightly closed, in a dry place at room temperature.

Water solubility:

19.1 g/L

Conc. based on:

element

Remarks:

lithium

Loading of aqueous phase:

1 007 other: Lithium neodecanoate

Incubation duration:

>= 9 - <= 11 d

Temp.:

20.9 °C

pH:

>= 10.5 - <= 11.2

Remarks on result:

other: S.D.: ± 1.2 g Li/L

Key result

Water solubility:

482 g/L

Conc. based on:

test mat. (dissolved fraction)

Remarks:

lithium neodecanoate

Loading of aqueous phase:

1 007 g/L

Incubation duration:

>= 9 - <= 11 d

Temp.:

20.9 °C

pH:

>= 10.5 - <= 11.2

Remarks on result:

other: S:D: ± 30 g/L

Details on results:

- Mean temperature during the test was 20.9 ± 0.3 °C (necessary range 20.0 ± 1.0 °C)
- the pH value of solutions containing the test item was in the range of 10.5 – 11.2
- the pH value in method blanks was in the range of 6.5 - 7.4
- Turbidity in samples from test (day 9) was always <1 NTU indicating that filtered solutions did not contain any undissolved material
- Analytical measurements:
Slight lithium concentrations in method blanks were detected (up to 14 µg/L), but far below the concentrations in test samples (19.1 g/L). Therefore, no background subtraction was performed. The concentrations in method blanks might be due to the ubiquitous lithium.
The calculated variations / changes between sampling points were less than 15 % for the days 9, 10 and 11. Furthermore, no increase of the lithium concentrations were observed. Thus, the validity criteria as foreseen in OECD 105 and Regulation 440/2008/EC A.6 were fulfilled.

ICP-OES measurement of test samples and method blanks with corresponding LOD/LOQ, correlation coefficient and sum of quality assurance samples and recovery.

date	Calibration [µg/L] – lowest and highest calibration point	Chosen wavelength [nm]	LOD [µg/L]	LOQ [µg/L]	correlation coefficient	Sum of quality assurance samples	Recovery of quality assurance samples [%]
May 24, 2018; measurement of test samples (9 d and 10 d) and method blanks	50 – 1000 (total of 12 calibration points, 11 used + blank)	Li: 670.783	Li: 0.04	Li: 0.11	Li: 0.99951	Li: 18	Li: 94.4
May 25, 2018; measurement of test samples (11 d) and method blanks	50 – 1000 (total of 11 calibration points, 11 used + blank)	Li: 670.783	Li: 0.04	Li: 0.12	Li:0.99985	Li: 13	Li: 100

                                      

Recovery / validation data lithium of measurement series

Element Li	Recovery [%]	SD [%]	n (total)	n (valid)
May 24, 2018
Quality control standard (Roth) 100 µg/L	106	1	4	4
Quality control standard (Roth) 500 µg/L	102	<1	4	4
Recalibration standard 250 µg/L	99.7	0.3	4	4
Recalibration standard 750 µg/L#	109	5	4	3
May 25, 2018
Quality control standard (Roth) 100 µg/L	103	0.2	3	3
Quality control standard (Roth) 500 µg/L	102	0.5	3	3
Recalibration standard 250 µg/L	97.6	0.2	3	3
Recalibration standard 750 µg/L	99.7	0.9	3	3

Fortification of measurement series

element	measured concentration [µg/L]	calculated level after addition [µg/L]	recovery [µg/L] / [%]
May 24, 2018
Li	638	608	592/ 97.4
Li	609	842	849/ 101
May 25, 2018
Li	697	299	291/ 97.2

The determination of the water solubility of lithium neodecanoate is based on mean lithium concentrations of sampling days (9, 10, 11 day) and a mean lithium amount of 3.964 % in the test item. The amount of dissolved lithium neodecanoate was calculated with a test item purity of 100 % (w/w) according to test substance data sheet as follows:

Mean Li concentrations
Vessel 1: 19.1± 1.1 g/L Li
Vessel 2: 19.1 ± 1.4 g/L Li
Mean: 19.1 ± 1.2 g/L Li

Based on a test item purity of 100 % the water solubility of lithium neodecanoate is:

Mean of concentration x 100 % / 3.964 %:

Vessel 1: 481± 28 g/L test item
Vessel 2: 482 ± 36 g/L test item
Mean: 482 ± 30 g/L test item

Conclusions:

Under the conditions of this test (under exclusion of CO2 and O2, under inert gas; flask method; loadings of 1.006 and 1.008 kg/L test substance in vessel 1 and 2, respectively), a solubility equilibrium was reached at day 9, 10, 11 of testing. The mean measured amount of dissolved lithium on day 9, 10 and 11 at a test temperature of 20.9 ± 0.3 °C is 19.1 ± 1.2 g/L (determined as dissolved lithium, separated by centrifugation from undissolved test item). This corresponds to a water solubility of dissolved lithium neodecanoate of 482 ± 30 g/L, calculated on a lithium content of 3.964 % and a test substance purity of 100 % (w/w). Solution pH in samples containing the test item remained at 10.5 – 11.2 while the pH in method blanks ranged from 6.5 - 7.4.

Description of key information

According to OECD Guideline 105 (1995) and EU Method 440/2008 A.6, the test item lithium neodecanoate has a water solubility of 482 ± 30 g/L at 20 °C.

Key value for chemical safety assessment

Water solubility:

482 g/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 1.006 and 1.008 kg/L test substance in vessel 1 and 2, respectively), a solubility equilibrium was reached at day 9, 10, 11 of testing. The mean measured amount of dissolved lithium on day 9, 10 and 11 at a test temperature of 20.9 ± 0.3 °C is 19.1 ± 1.2 g/L (determined as dissolved lithium, separated by centrifugation from undissolved test item). This corresponds to a water solubility of dissolved lithium neodecanoate of 482 ± 30 g/L, calculated on a lithium content of 3.964 % and a test substance purity of 100 % (w/w). Solution pH in samples containing the test item remained at 10.5 – 11.2 while the pH in method blanks ranged from 6.5 - 7.4.