Fatty acids, C6-19-branched, copper(2+) salts

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-05-30 to 2018-08-03

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, 2019-07-15 (inspection date: 2018-10-25)

Type of method:

flask method

Specific details on test material used for the study:

Appearance: solid, highly viscous, sticky, green
Storage conditions: Keep container tightly closed, in a dry place at room temperature

Key result

Water solubility:

53.1 mg/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

574.5 mg/L

Incubation duration:

34 d

Temp.:

20 °C

pH:

>= 6.07 - <= 6.14

Remarks on result:

other: S.D: ± 6.1 mg/L

Remarks:

Calculated on a mean dissolved copper concentration of 5.84 ± 0.67 mg/L and a copper content of 11 %.

Water solubility:

5.84 mg/L

Conc. based on:

element (dissolved fraction)

Remarks:

Cu

Loading of aqueous phase:

574.5 other: mg test item /L

Incubation duration:

34 d

Temp.:

20 °C

pH:

>= 6.07 - <= 6.14

Remarks on result:

other: S.D: ± 0.76 mg/L

Details on results:

Observations
- 1st test: a resinous substance sticked at the sample boats until day 10. Then the undissolved material was extensively dispersed inside the vessel.
- 2nd test: an undissolved substance is located at the bottom of the test item loaded vessels mostly in the middle.
Temperature: The mean temperature was 19.0 ± 0.2 °C in the 1st and 20.0 ± 0.4 °C in the 2nd test.
Oxygen: no oxygen was detectable in both tests
pH:
- 1st test: test item solutions: 5.5 – 6.8; method blanks: 6.4 – 7.3.
- 2nd test: test item solutions: 4.9 – 6.6; method blanks: 6.7 – 7.8.
Turbidity: In both tests were always <1 NTU indicating that filtered solutions did not contain any undissolved material.

ICP-OES measurement with corresponding LOD/LOQ, correlation coefficient and sum of quality assurance samples and recovery (2^nd test).

Calibration [µg/L] – lowest and highest calibration point	Chosen wavelength [nm]	LOD [µg Cu /L]	LOQ [µg Cu /L]	Correlation coefficient	Sum of quality assurance samples	Recovery / validity of quality assurance samples [%]
July 02, 2018 measurement of samples from d3
1 – 1000 (total of 13 calibration points, 12 used + blank)	219.227	0.748	2.24	0.999947	13	100
July 03, 2018 measurement of samples from d4
1 – 1000 (total of 13 calibration points, 13 used + blank)	224.700	1.65	4.94	0.999945	13	100
July 04, 2018 measurement of samples from d5
1 – 1000 (total of 13 calibration points, 12 used + blank)	219.227	0.538	1.61	0.999986	13	100
July 10, 2018 measurement of samples from d11
2.5 – 1000 (total of 13 calibration points, 12 used + blank)	224.700	1.86	5.59	0.999986	13	100
July 11, 2018 measurement of samples from d12
2.5 – 1000 (total of 13 calibration points, 12 used + blank)	224.700	1.68	5.03	0.999978	13	100
July 12, 2018 measurement of samples from d13
1 – 1000 (total of 13 calibration points, 12 used + blank)	219.227	2.83	8.49	0.999986	13	100
July 17, 2018 measurement of samples from d13
1 – 1000 (total of 13 calibration points, 13 used + blank)	224.700	1.02	3.05	0.999981	13	100
July 18, 2018 measurement of samples from d19
2.5 – 750 (total of 12 calibration points, 11 used + blank)	223.009	3.55	10.6	0.999965	13	100
July 19, 2018 measurement of samples from d20
1 – 1000 (total of 13 calibration points, 12 used + blank)	224.700	0.665	1.99	0.999975	13	100
July 31, 2018 measurement of samples from d32
25 – 1000 (total of 13 calibration points, 8 used + blank)	217.895	2.31	6.93	0.999994	21	100
August 01, 2018 measurement of samples from d33
2.5 – 1000 (total of 13 calibration points, 12 used + blank)	224.700	0.913	2.74	0.999989	21	100
August 02, 2018 measurement of samples from d34
1 – 1000 (total of 13 calibration points, 13 used + blank)	224.700	0.535	1.61	0.999964	21	100
August 03, 2018 measurement of samples from d35
1 – 1000 (total of 13 calibration points, 13 used + blank)	224.700	0.204	0.611	0.999945	13	100

 

Recovery/validation data copper of the 2^nd test

Date	Recovery [%] ± SD [%] (n total/ n valid)
	Recalibration standard 50 µg/L	Recalibration standard 500 µg/L	Quality control standard (Roth) 100 µg/L	TMDA-70.2 nominal value 406 µg/L diluted 2-fold nominal value 203 µg/L	Quality control standard (Roth) 750 µg/L
July 02, 2018	95.2 ± 2.2 (3/3)		106 ± 1 (3/3)	103 ±1 (3/3)	103 ± 1 (3/3)
July 03, 2018	100 ± 1 (3/3)		106 ± 1 (3/3)	103 ± 1 (3/3)	103 ± 1 (3/3)
July 03, 2018	99.2 ± 1.0 (3/3)		106 ± <1 (3/3)	104 ± 1 (3/3)	103 ± <1 (3/3)
July 10, 2018	96.8 ± 0.4 (3/3)		103 ± 1 (3/3)	102 ± <1 (3/3)	101 ± <1 (3/3)
July 11, 2018	98.9 ± 0.8 (3/3)		103 ± 1 (3/3)	101 ± 1 (3/3)	101 ± 1 (3/3)
July 12, 2018	97.1 ± 0.9 (3/3)		103 ± 1 (3/3)	101 ± 2 (3/3)	102 ± <1 (3/3)
July 17, 2018		98.9 ± 0.9 (3/3)	104 ± 2 (3/3)	101 ± <1 (3/3)	101 ± 1 (3/3)
July 18, 2018		99.0 ± 0.6 (3/3)	107 ± <1 (3/3)	104 ± 1 (3/3)	102 ± <1 (3/3)
July 19, 2018		98.3 ± 0.6 (4/4)	103 ± 1 (4/4)	101 ± 1 (4/4)	101 ± 1 (4/4)
July 31, 2018		97.4 ± 0.9 (5/5)	102 ± 1 (5/5)	101 ± 2 (5/5)	99.6 ± 0.4 (5/5)
August 01, 2018		100 ± 1 (5/5)	103 ± 1 (5/5)	105 ± 1 (5/5)	102 ± <1 (5/5)
August 02, 2018		99.3 ± 1.5 (5/5)	103 ± 2 (5/5)	102 ± <1 (5/5)	102 ± 2 (5/5)
August 03, 2018		98.8 ± 0.8 (3/3)	103 ± 1 (3/3)	101 ± 1 (3/3)	101 ± 1 (3/3)

A selected sample was fortified with a known amount of copper (by standard addition of commercial standard) to determine the standard recovery of this element.

Cu fortification: Measurement series from the 2^nd test

Sample / Date	Measured concentration [µg/L]	Calculated level after addition [µg/L]	Recovery [µg/L] / [%]
July 02, 2018
Vessel 1 sample a 3d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	255	131	132 / 101
July 03, 2018
Vessel 1 sample a 4d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	266	133	141 / 106
July 04, 2018
Vessel 1 sample a 5d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	278	136	136 / 100
July 10, 2018
Vessel 1 sample a 11d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	330	146	146 / 99.7
July 11, 2018
Vessel 1 sample a 12d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	331	146	146 / 99.7
July 12, 2018
Vessel 1 sample a 13d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	345	149	148 / 99.4
July 17, 2018
Vessel 1 sample a 13d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	377	155	155 / 99.4
July 18, 2018
Vessel 1 sample a 19d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	395	159	154 / 97.0
July 19, 2018
Vessel 1 sample a 20d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	400	160	162 / 101
July 31, 2018
Vessel 1 sample a 32d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	514	183	181 / 98.9
August 01, 2018
Vessel 1 sample a 33d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	555	191	193 / 101
August 02, 2018
Vessel 1 sample a 34d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	534	187	190 / 102
August 03, 2018
Vessel 1 sample a 35d sampling; dilution 10-fold; 1 mL sample + 4 mL 100 µg/L standard	559	192	196 / 102

Results:

1^st test

Background copper levels of method blanks remained ≤ 5 µg Cu/L during the whole test. A background correction was not considered relevant, since copper concentrations of solutions containing the test item are at least 650 times higher.

The variation between the sampling days for the copper concentration measured was less than 15 % for the days 2, 3, 10, 11, 15 and 16. Thus, the validity criteria were fulfilled. However, since the relative standard deviation of analysed copper content between the two replicate test vessels after 3 days of testing varies between 13.3 % and 39.7 % and a slight increase of the copper concentration was observed till test day 17, the test was repeated.

2^nd test

Background copper levels of method blanks remained ≤ 11 µg Cu/L during the whole test. A background correction was not considered relevant, since copper concentrations of solutions containing the test item are at least 200 times higher.

The variation between the sampling days for the copper concentration measured was less than 15 % for at least the days 33 and 34. Hence, the test is considered as fully reliable. Nevertheless, the copper concentration in vessel 2 on day 35 increases significantly. This may be due to the low remaining test item solution. Hence, as proposed by the study monitor, values of day 35 of testing were neglected. Since, the values in the three replicate test vessels slightly increases (< 15 % as described above) during the test period of 35 days and based on the low remaining test item solution on day 35, the copper concentration analysed on day 34 was used to report the water solubility of the test item. There is still no solubility equilibrium reached till day 35 of testing. However, the water solubility of “fatty acids, C6-19-branched, copper salts“ on day 34 is 53.1 ± 6.1 mg/L, based on a mean copper concentration of 5.84 ± 0.67 mg Cu/L analysed via ICP-OES and a copper content of 11 % in test item.

 

Mean Cu concentrations:

Vessel 1: 5.39 ± 0.08 mg/L

Vessel 2: 5.44 ± 0.01 mg/L

Vessel 3: 6.71 ± 0.12 mg/L

Mean: 5.84 ± 0.67 mg/L

 

Based on a copper content of 11 % the water solubility ofthe test item is:

Mean of concentration x 100 % / 11.0 %:

Vessel 1: 49.0 ± 0.7 mg/L

Vessel 2: 49.4 ± 0.1 mg/L

Vessel 3: 61.0 ± 1.1 mg/L

Mean: 53.1 ± 6.1 mg/L

Conclusions:

Under the conditions of the test (under exclusion of CO2 and O2, under inert gas; flask method; loadings of 430.8, 425.3 and 522.7 mg/L test substance in three replicate test vessels, a solubility equilibrium was not observed during testing. However, the dissolved copper concentration analysed on day 34 of testing is 5.84 ± 0.67 mg/L (determined as dissolved copper, separated by filtration from undissolved test item) at 20.0 ± 0.4 °C This corresponds to a water solubility of “fatty acids, C6-19-branched, copper salts” of 53.1 ± 6.1 mg/L, calculated on a copper content of 11.0 %.

The pH of solutions containing the test item ranged between 4.9 – 6.6. The pH in method blanks remained in the range of 6.1 – 7.8.

Description of key information

Fatty acids, C6-19-branched, copper salts has a water solubility of 53.1 ± 6.1 mg/L at 20 °C.

Key value for chemical safety assessment

Water solubility:

53.1 mg/L

at the temperature of:

20 °C

Additional information

Under the conditions of the test (under exclusion of CO₂ and O₂, under inert gas; flask method; loadings of 430.8, 425.3 and 522.7 mg/L test substance in three replicate test vessels, a solubility equilibrium was not observed during testing. However, the dissolved copper concentration analysed on day 34 of testing is 5.84 ± 0.67 mg/L (determined as dissolved copper, separated by filtration from undissolved test item) at 20.0 ± 0.4 °C This corresponds to a water solubility of “fatty acids, C6-19-branched, copper salts” of 53.1 ± 6.1 mg/L, calculated on a copper content of 11.0 %.

The pH of solutions containing the test item ranged between 4.9 – 6.6. The pH in method blanks remained in the range of 6.1 – 7.8.