Hydrocarbons, C10-C13, n-alkanes, isoalkanes,

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental Starting Date: 10 July 2014; Experimental Completion Date: 13 September 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Qualifier:

according to guideline

Guideline:

other: slow-stir adaptation of standard method

Deviations:

no

Principles of method if other than guideline:

The water solubility of Shell GTL Solvent GS190 at 20.0 ± 0.5 °C was evaluated using a slow stir adaptation of the standard test method, based on the findings of Letinski, D.J., Connolly, M.J., Peterson, D.R. and Parkerton, T.F. (2002) “Slow-stir water solubility measurements of selected alcohols and diesters”, Chemosphere 48, 257-265. The method employed was designed to be compatible with the data endpoint requirements of Method A6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

GLP compliance:

yes

Type of method:

other: Slow stir adaptation of standard method

Key result

Water solubility:

< 0 g/L

Temp.:

20 °C

Remarks on result:

other: Initial Nominal Loading Rate of 100 mg/L

Key result

Water solubility:

< 0 g/L

Temp.:

20 °C

Remarks on result:

other: Initial Nominal Loading Rate of 10 mg/L

Results

Main Test

The mean peak area ratios relating to the standard, sample and blank solutions are shown in the following tables:

 

Table 3.1– Nominal 100 mg/L Loading Rate

Solution	Mean Peak Area Ratio
Standard 11.1 mg/L	1.5999
Standard 11.0 mg/L	1.5818
Vessel 1 Sample 1	0.15768
Vessel 2 Sample 1	0.13665
Vessel 3 Sample 1	0.12595
Sample Blank	0.014509
Standard 10.5 mg/L	1.4254
Standard 10.2 mg/L	1.3907
Vessel 1 Sample 2	0.16710
Vessel 1 Sample 3	0.16684
Vessel 2 Sample 2	0.17302
Vessel 2 Sample 3	0.35982
Vessel 3 Sample 2	0.17046
Vessel 3 Sample 3	0.15483
Sample Blank	0.020956
Standard 11.9 mg/L	1.6406
Standard 13.1 mg/L	1.8311
Vessel 1 Sample 4	0.43118
Vessel 1 Sample 5	0.16093
Vessel 2 Sample 4	0.17218
Vessel 2 Sample 5	0.16282
Vessel 3 Sample 4	0.17277
Vessel 3 Sample 5	0.15622
Sample Blank	0.028965

 

Table 3.1– Nominal 100 mg/L Loading Rate - Continued

Solution	Mean Peak Area Ratio
Standard 14.2 mg/L	1.9928
Standard 11.9 mg/L	1.6761
Vessel 1 Sample 6	0.16820
Vessel 2 Sample 6	0.13793
Vessel 3 Sample 6	0.17215
Sample Blank	0.026360

 

Table 3.2– Nominal 10 mg/L Loading Rate

Solution	Mean Peak Area Ratio
Standard 11.1 mg/L	1.5999
Standard 11.0 mg/L	1.5818
Vessel 1 Sample 1	0.053644
Vessel 2 Sample 1	0.058875
Vessel 3 Sample 1	0.35890
Sample Blank	0.014509
Standard 10.5 mg/L	1.4490
Standard 10.2 mg/L	1.4185
Vessel 1 Sample 2	0.065406
Vessel 1 Sample 3	0.068723
Vessel 2 Sample 2	0.073820
Vessel 2 Sample 3	0.056500
Vessel 3 Sample 2	0.065886
Vessel 3 Sample 3	0.057005
Sample Blank	0.020956

 

 

Table 3.2– Nominal 10 mg/L Loading Rate - Continued

Solution	Mean Peak Area Ratio
Standard 11.9 mg/L	1.6368
Standard 13.1 mg/L	1.7757
Vessel 1 Sample 4	0.16045
Vessel 1 Sample 5	0.070502
Vessel 2 Sample 4	0.071404
Vessel 2 Sample 5	0.063779
Vessel 3 Sample 4	0.082443
Vessel 3 Sample 5	0.091781
Sample Blank	0.028965
Standard 14.2 mg/L	1.9928
Standard 11.9 mg/L	1.6761
Vessel 1 Sample 6	0.075318
Vessel 2 Sample 6	0.078646
Vessel 3 Sample 6	0.080393
Sample Blank	0.026360

 

As the test item peaks covered a wide retention time range and there were peaks observed in the blank solutions over the same range, the concentration attributed to the blank was subtracted from the sample concentrations. 

 

The concentration (g/L) of test item in the sample solutions corrected for blank response is shown in the following tables:

 

Table 3.3– Nominal 100 mg/L Loading Rate, Vessel 1

Sample Number	Stirring / Equilibration Time (hours)	Concentration (g/L)	Solution pH
1	22.6	9.94 x 10^-6	6.49
2	46.2	1.07 x 10^-5	6.62
3	52.0	1.07 x 10^-5	6.66
4	71.1	2.90 x 10^-5	6.49
5	77.1	9.50 x 10^-6	6.74
6	94.1	1.01 x 10^-5	6.90

 

A negligible quantity was detected in the retention time range of the test item in both samples and sample blank. The amount detected was below the range investigated for the analysis. The result is therefore taken as less than the level at which successful detection of the test item was achieved. See validation and discussion within the Overall remarks and attachment section below.

 

Table 3.4– Nominal 100 mg/L Loading Rate, Vessel 2

Sample Number	Stirring / Equilibration Time (hours)	Concentration (g/L)	Solution pH
1	22.6	8.48x 10^-6	6.51
2	46.2	1.11x 10^-5	6.69
3	52.0	2.48x 10^-5	6.66
4	71.1	1.03x 10^-5	6.71
5	77.1	9.64x 10^-6	6.54
6	94.1	7.95x 10^-6	6.59

 

A negligible quantity was detected in the retention time range of the test item in both samples and sample blank. The amount detected was below the range investigated for the analysis. The result is therefore taken as less than the level at which successful detection of the test item was achieved. See validation and discussion within the Overall remarks and attachment section below.

 

 

Table 3.5– Nominal 100 mg/L Loading Rate, Vessel 3

Sample Number	Stirring / Equilibration Time (hours)	Concentration (g/L)	Solution pH
1	22.6	7.74x 10^-6	6.47
2	46.2	1.09x 10^-5	6.74
3	52.0	9.80x 10^-6	6.62
4	71.1	1.04x 10^-5	6.51
5	77.1	9.16x 10^-6	6.62
6	94.1	1.04x 10^-5	6.68

 

A negligible quantity was detected in the retention time range of the test item in both samples and sample blank. The amount detected was below the range investigated for the analysis. The result is therefore taken as less than the level at which successful detection of the test item was achieved. See validation and discussion within the Overall remarks and attachment section below.

 

Table 3.6– Nominal 10 mg/L Loading Rate, Vessel 1

Sample Number	Stirring / Equilibration Time (hours)	Concentration (g/L)	Solution pH
1	22.6	2.72x 10^-6	6.69
2	46.2	3.17x 10^-6	6.91
3	52.0	3.41x 10^-6	7.00
4	71.1	9.66x 10^-6	6.66
5	77.1	3.07x 10^-6	6.72
6	94.1	3.49x 10^-6	6.99

 

A negligible quantity was detected in the retention time range of the test item in both samples and sample blank. The amount detected was below the range investigated for the analysis. The result is therefore taken as less than the level at which successful detection of the test item was achieved. See validation and discussion within the Overall remarks and attachment section below.

 

 

Table 3.7– Nominal 10 mg/L Loading Rate, Vessel 2

Sample Number	Stirring / Equilibration Time (hours)	Concentration (g/L)	Solution pH
1	22.6	3.08x 10^-6	6.68
2	46.2	3.77x 10^-6	6.99
3	52.0	2.53x 10^-6	6.92
4	71.1	3.14x 10^-6	6.69
5	77.1	2.58x 10^-6	6.64
6	94.1	3.72x 10^-6	7.02

 

A negligible quantity was detected in the retention time range of the test item in both samples and sample blank. The amount detected was below the range investigated for the analysis. The result is therefore taken as less than the level at which successful detection of the test item was achieved. See validation and discussion within the Overall remarks and attachment section below.

Table 3.8– Nominal 10 mg/L Loading Rate, Vessel 3

Sample Number	Stirring / Equilibration Time (hours)	Concentration (g/L)	Solution pH
1	22.6	2.39x 10^-5	6.72
2	46.2	3.20x 10^-6	6.71
3	52.0	2.56x 10^-6	6.84
4	71.1	3.95x 10^-6	6.74
5	77.1	4.63x 10^-6	6.72
6	94.1	3.85x 10^-6	6.84

 

A negligible quantity was detected in the retention time range of the test item in both samples and sample blank. The amount detected was below the range investigated for the analysis. The result is therefore taken as less than the level at which successful detection of the test item was achieved. See validation and discussion within the Overall remarks and attachment section below.

 

 

The overall water solubility results for the two different loading rates evaluated are summarized in the following tables:

 

Table3.9– Nominal 100 mg/L Loading Rate

Vessel	1	2	3
Mean Water Solubility (g/L at 20.0 ± 0.5 ºC)	< 1.11 x 10^-4	< 1.11 x 10^-4	< 1.11 x 10^-4
Standard Deviation	not applicable	not applicable	not applicable
Relative Standard Deviation	not applicable	not applicable	not applicable

 

Overall water solubility                             :         less than 1.11x 10^-4g/L at 20.0 ± 0.5 ºC

 

Table3.10– Nominal 10 mg/L Loading Rate

Vessel	1	2	3
Mean Water Solubility (g/L at 20.0 ± 0.5 ºC)	< 1.11 x 10^-4	< 1.11 x 10^-4	< 1.11 x 10^-4
Standard Deviation	not applicable	not applicable	not applicable
Relative Standard Deviation	not applicable	not applicable	not applicable

 

Overall water solubility                             :         less than 1.11x 10^-4g/L at 20.0 ± 0.5 ºC

Conclusions:

Interpretation of results: insoluble (< 0.1 mg/L)

Please see the Conclusion within the Executive Summary section below.

Executive summary:

The determination was carried out using a slow stiradaptation of the standard test method, based on thefindings of Letinski, D.J., Connolly, M.J., Peterson, D.R. and Parkerton, T.F. (2002) “Slow-stir water solubility measurements of selected alcohols and diesters”, Chemosphere 48, 257-265. The method employed was designedto be compatible with the data endpoint requirements of Method A6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

 

The slow-stir procedure was used as during a previous study (Harlan Study Number 41304203) using the flask method, it was identified that excess, undissolved test item could not be successfully excluded from the saturated solutions. The slow stir method eliminated dispersion of the test item throughout the solution and thus allowed isolation of saturated solutions free from excess, undissolved test item suitable for analysis.

 

Slow-stirring therefore enables the solubilisation of the test item without the formation of potentially problematic micro-droplets. The alternative column elution method proposed by the guidelines for addressing substances of low solubility is poorly suited to liquid test items.

 

As the test item is a UVCB substance, the effect of initial loading rate was also evaluated during the definitive determination of water solubility, using initial nominal loading rates of 100 mg/L and 10 mg/L, in order to assess if this affected either the resulting aqueous concentration or the composition of the dissolved fraction.

Conclusion

The water solubility of the test item at 20.0 ± 0.5 °C was evaluated using a slow stiradaptation of the standard test method. The results are summarized in the following table:

 

Table 3.11

Initial Nominal Loading Rate	Water Solubility  (g/L of solution at 20.0 ± 0.5 °C)
100 mg/L	< 1.11x 10^-4
10 mg/L	< 1.11x 10^-4

Description of key information

Water solubility (whole substance): <0.1 mg/l at 20±0.5°C (measured).

Water solubility (individual constituents): 9.0E-04 - 1.0E-01 mg/l at 20°C (QSAR).

Additional information

The substance is a hydrocarbon UVCB and the constituent hydrocarbons will exhibit a wide range of water solubility.

The "whole substance" water solubility of Hydrocarbons, C10-C13, n-alkanes, isoalkanes, <2% aromatics was evaluated using a slow-stir method (Tarran, 2015). The method was designed to be compatible with EU Method A.6 and OECD 105. Since the submission substance is a UVCB, the effect of initial loading rate was also evaluated during the definitive study using initial nominal loading rates of 100 mg/l and 10 mg/l to assess if the resulting aqueous concentration or composition of the dissolved fraction were affected. The water solubility of Hydrocarbons, C10-C13, n-alkanes, isoalkanes, <2% aromatics was determined to be <0.1 mg/l at 20±0.5°C in both the 100 mg/l and 10 mg/l loading rates.

As supporting information, the water solubility of each constituent has also been predicted using a separately validated QSAR estimation method. The prediction method uses a fragment method and water solubility decreases with increasing carbon number. The prediction domain covers carbon chain length in the range C2-C15, it is therefore expected that water solubility for longer chain length (i.e. greater than C15) compounds will be lower than the predicted value for C15 atom. Thus the water solubility of the individual constituents is in the range 9.0E-04 mg/l - 1.0E-01 mg/l at 20°C.