Pyrolytic sugar

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jan 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

July 1995

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

January 2014

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

1,6-anhydro-β-D-glucose

EC Number:

207-855-0

EC Name:

1,6-anhydro-β-D-glucose

Cas Number:

498-07-7

Molecular formula:

C6H10O5

IUPAC Name:

(1R,2S,3S,4R,5R)-6,8-dioxabicyclo[3.2.1]octane-2,3,4-triol

Constituent 2

Reference substance name:

Glycollaldehyde

EC Number:

205-484-9

EC Name:

Glycollaldehyde

Cas Number:

141-46-8

Molecular formula:

C2H4O2

IUPAC Name:

2-hydroxyacetaldehyde

Constituent 3

Reference substance name:

Organic acids

IUPAC Name:

Organic acids

Constituent 4

Reference substance name:

Ketones

IUPAC Name:

Ketones

Constituent 5

Reference substance name:

Phenols

IUPAC Name:

Phenols

Constituent 6

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

water

Constituent 7

Reference substance name:

Oligomers of sugars and anhydrosugars

IUPAC Name:

Oligomers of sugars and anhydrosugars

Test material form:

liquid: viscous

Results and discussion

Water solubility

Water solubility 1

Key result

Water solubility:

7.32 mg/L

Conc. based on:

test mat.

Loading of aqueous phase:

10 mg/L

Incubation duration:

3 d

Temp.:

20 °C

pH:

>= 5 - <= 6

Water solubility 2

Key result

Water solubility:

960 mg/L

Conc. based on:

test mat.

Loading of aqueous phase:

1 003 mg/L

Incubation duration:

3 d

Temp.:

20 °C

pH:

>= 5 - <= 6

Details on results:

A strong dependency of the solubility on the amount of the test item (nominal load) was perceived in the flasks 1 – 6.
As the solubility was dependent on the nominal concentration, no exact value for the solubility of the test item in water can be stated. Dependency of the pH value on the amount of the test item (nominal load) was perceived in the main test. Therefore the concentration of the test item in water is reported as a range: 7.32-960mg/L at 20.0°C.

Any other information on results incl. tables

Measurements during Equilibration

Day	Flask	Temperature [°C]	pH*	Concentration DOC Mean [mg/L]	Conc. DOC – blank [mg/L]	Conc. test item [mg/L]	Difference [%]
1	1A	20.0	5-6	221	221	453	-
2	1B	20.0	5-6	205	205	422	-7.1
3	1C	20.0	5-6	231	231	475	12.7
3	blank	20.0	6	0.25	-	-	-

The measured value in the blank flask was subtracted from the measured value in the flasks 1A – 1C.

After the analysis of the sample of day 3, the plateau was considered as reached.

Measurements at Plateau

Flask	pH*	Concentration DOC Mean [mg/L]	Conc. DOC – blank [mg/L]	Conc. test item [mg/L]
2	6.16	3.82	3.57	7.32
3	5.04	20.3	20.2	41.1
4	4.57	45.2	44.8	92.0
5	3.68	381	382	782
6	3.70	468	468	960

*measured via calibrated pH meter

 

The measured value in the blank flask 0.25 mg/L was subtracted from the measured value in the flasks 2 – 6.

Temperature was measured with 20.0 °C.

 Results

Flask	Measured Conc. Test Item [mg/L]	Nominal Conc. Test Item [mg/L]	Dissolved Part [%]
2	7.32	10	72.5
3	41.1	50	82.3
4	92.0	101	91.5
1*	450	501	89.7
5	781	754	103.6
6	960	1003	95.7

*mean value of flasks 1A – 1C

Conclusion

As solubility was dependent on nominal concentration, no exact value for the solubility of the test item in water can be stated. The solubility range for the tested nominal concentration 10 – 1003 mg/L is 7.32 – 960 mg/L at 20.0 ± 0.5 °C (7.32 – 960 kg/m³in SI units), corresponding to 72.5 – 103.6 % of the test item relating to the nominal concentration of the test item.

Applicant's summary and conclusion

Conclusions:

The water solubility was found to be dependent on the nominal concentration. Therefore, the solubility range for the tested nominal concentration 10 – 1003 mg/L is 7.32 – 960 mg/L at 20.0 ± 0.5 °C, corresponding to 72.5 – 103.6 % of the test item relating to the nominal concentration of the test item.

Executive summary:

The solubility of the test item in water was determined, according to OECD 105, by measurement of DOC concentration in the filtrated test solutions using TOC analyser.

During pre-tests for development of a specific analytical method several marker component candidates were tested for quantification of this UVCB substance via LC/MS/MS analysis. As the water solubility of components in UVCB substances can differ substantially, it was considered inadequate to base the water solubility of the mixture on a number of specific components because no information on the solubility of the remaining components is possible.

Therefore, the determination of total organic carbon was favored, because the solubility of the sum of all components is recorded and thus more meaningful information is generated.

As the test item is a UVCB substance, six different loading rates of the test item were chosen to study the effect of the loading rate on the measured water solubility: 10, 50, 100, 500, 750 and 1000 mg/L. Three flasks (1A – 1C) with the same loading rate (500 mg/L) were used during equilibration. Seven vessels (flasks blank, 1C (for the sampling point 72 h) and 2 – 6) were set onto the shaking apparatus immediately and shaking at 150 rpm was started. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature. Then, flasks 1A – 1C were removed from the shaker, tempered at 20.0 ± 0.5 °C, samples were taken, membrane filtered and analysed for DOC via TOC analyser.

Because of a difference of less than 15 % in the concentrations on days 2 and 3 and no upward tendency in the last three values, the test was finished. The final measurement was performed as determination from flasks 2 – 6. DOC was measured via TOC analyser in the saturated aqueous solutions. The pH value in the flasks 2 – 6 lay in the range of 3.70 – 6.16.

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicating that no colloidal dispersed particles were present.

A strong dependency of the solubility on the amount of the test item (nominal load) was per-ceived in the flasks 1 – 6.

As the solubility was dependent on the nominal concentration, no exact value for the solu-bility of the test item in water can be stated. Dependency of the pH value on the amount of the test item (nominal load) was perceived in the main test.

 

Therefore, the concentration of the test item in water was stated as

 

7.32 – 960 mg/L at 20.0 ± 0.5 °C

7.32 – 960 * 10^-3kg/m³(SI units)

 

for the following nominal concentration range of the test item in water: 10 – 1003 mg/L, corresponding to a dissolved part of 92.6 ± 7.9 %of the test item (mean value) relating to the nominal concentration of the test item.