Resin acids and Rosin acids, dimers, calcium zinc

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 2016 - October 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted to standard guidelines and with GLP. Report well documented.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

Identification: Rosin dimers, calcium, zinc salt
Appearance/Physical state: Pale brown crystalline solid
Batch: 179449
Purity: 100% (as UVCB)
Expiry date: 24 March 2017
Storage conditions: Approximately 4 °C, under nitrogen, in the dark

Water solubility:

0.001 g/L

Conc. based on:

test mat.

Incubation duration:

> 24 - < 72 h

Temp.:

20 °C

pH:

> 5.8 - < 6.14

Details on results:

Preliminary Test
The preliminary estimate of water solubility was 6.1 x 10^-4 g/L at 20 °C.

Main Test
On removal of the samples from the static 20 °C waterbath, all solutions were observed to be visually clear and colorless, with excess, undissolved test item mostly present on the surface. Evaluation of the sample filtrates prior to analysis indicated a positive Tyndall beam for all 0.20 g/L nominal loading rate samples. Previous evaluations indicated that repeated filtration through 0.2 µm filters did not remove the material generating the Tyndall beam.

The calibration curve from which the sample concentrations were interpolated can be described by the following calibration curve equation:
y = 1.1415 x 10^6 · x + 1.2042 x 10^8
Correlation coefficient: r = 0.9998

Validation
Recovery of analysis of the sample extraction procedure was assessed and proved adequate for the test. At a nominal fortified concentration of 0.5 mg/L, a mean percentage recovery of 93.2% was obtained (n = 3, range 92.7 to 94.2%, relative standard deviation 0.852%). Reported sample solution concentrations have not been corrected for recovery of analysis. The test item was visually assessed to be soluble in dichloromethane at a nominal concentration of 1.0 g/L.

The main test was initiated using two nominal loading rates of 0.20 g/L and 2.00 g/L. However, on shaking under standard test conditions, with the exception of a single sample at 0.20 g/L, all samples formed stable colloidal dispersions to some degree. Therefore, saturated solutions free from excess, undissolved test item could not be isolated and this testing was considered not valid. Consequently, a second definitive test was performed reducing the nominal loading rate concentrations to 0.02 g/L and 0.20 g/L. In addition, a less vigorous shaking speed was used during the saturation period in an attempt to minimize dispersion of the test item. There is a time dependent trend; such that the degree of dispersion increased with an increase in the shaking/saturation time. The definitive water solubility result has been taken from the lower nominal loading rate of 0.02 g/L, for which saturated filtrates free from excess, undissolved test item could be isolated and analyzed. No significant test item responses were obtained for these sample solutions (when compared to the sample solution matrix blank) despite concentrating the sample solutions by a factor of 100 prior to analysis. It was therefore necessary to report a limit value for the water solubility of the test item. The limit value reported (<1.0 x 10^-4 g/L, equivalent to <0.10 mg/L) originated from the nominal concentration of the lowest calibration standard (10 mg/L), corrected for the dilution factor introduced by the sample extraction procedure (0.01). It was noted that a significant instrument response was achieved for the standard and sample solution matrix blank solutions on analysis, originating from the gradient elution method required for analysis of the test item and the partial UV absorbance of tetrahydrofuran at the analytical wavelength needed to monitor the test item. This had no impact on the integrity of the results reported, since incorporating the standard matrix blank into the calibration plot automatically corrects for the blank response. The sample matrix blank was essentially identical to the standard matrix blank on analysis and hence no further correction was necessary. Although the solubility of the test item was below 1.0 x 10^-2 g/L, the flask method was employed to allow evaluation of the influence of loading rate. Also, the column elution method is applicable to pure substances only.

Conclusion
The water solubility of the test item has been determined to be less than 1.0 x 10^-4 g/L (0.10 mg/L) of solution at 20.0 ± 0.5 °C.

Table 1. Mean peak areas relating to the standard, sample and blank solutions.

Solution	Mean Peak Area
Standard Matrix Blank	1.1996 x 10^8
Standard Solution 10.3 mg/L	1.3184 x 10^8
Standard Solution 25.7 mg/L	1.4952 x 10^8
Standard Solution 51.4 mg/L	1.7918 x 10^8
Standard Solution 52.8 mg/L	1.8229 x 10^8
Standard Solution 82.2 mg/L	2.1428 x 10^8
Standard Solution 103 mg/L	2.3675 x 10^8
Sample Matrix Blank	1.2143 x 10^8
0.02 g/L Sample Solution 1, Replicate A	1.2272 x 10^8
0.02 g/L Sample Solution 1, Replicate B	1.2222 x 10^8
0.02 g/L Sample Solution 2, Replicate A	1.2229 x 10^8
0.02 g/L Sample Solution 2, Replicate B	1.2323 x 10^8
0.02 g/L Sample Solution 3, Replicate A	1.2090 x 10^8
0.02 g/L Sample Solution 3, Replicate B	1.2197 x 10^8
0.2 g/L Sample Solution 4, Replicate A	1.6676 x 10^8
0.2 g/L Sample Solution 4, Replicate B	1.6763 x 10^8
0.2 g/L Sample Solution 5, Replicate A	1.9406 x 10^8
0.2 g/L Sample Solution 5, Replicate B	1.9404 x 10^8
0.2 g/L Sample Solution 6, Replicate A	2.0085 x 10^8
0.2 g/L Sample Solution 6, Replicate B	2.0109 x 10^8

Table 2. Nominal 0.02 g/L Initial Saturation Loading Rate Samples

Sample number	Time shaken at 30 ºC (h)	Time equilibrated at 20 ºC	Concentration (g/l)	Solution pH
1	24	24	<1.0 x 10^-4	5.80
2	48	24	<1.0 x 10^-4	5.85
3	72	24	<1.0 x 10^-4	5.74

Conclusions:

The overall water soubility of calcium zinc salt of oligomers of rosin was <1.0 x 10^-4 g/L at 20.0 ± 0.5 ºC

Executive summary:

The water solubility of calcium zinc salts of oligomers of rosin was determined using the shake flask method according to OECD guideline 105. The overall water soubility of calcium zinc salt of oligomers of rosin was <1.0 x 10^-4 g/L at 20.0 ± 0.5 ºC.

Description of key information

The water solubility of calcium zinc salts of oligomers of rosin was determined using the shake flask method according to OECD guideline 105. The overall water soubility of calcium zinc salt of oligomers of rosin was <1.0 x 10^-4 g/L at 20.0 ± 0.5 ºC.

Key value for chemical safety assessment

Water solubility:

0 g/L

at the temperature of:

20 °C