Sulfates of potassium, sodium and calcium, byproduct from fermentation

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14-07-2017 to 11-09-2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 97.1 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate

Loading of aqueous phase:

100 other: mg/L of test item

Incubation duration:

2 h

Test conditions:

- Reconstituted standard based on ISO 6341;
- The aqueous medium solution sterilized by filtration (0.2 µm)
- pH=7;
- 20 +/- 1 °C;
- dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 97.7 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate

Loading of aqueous phase:

100 other: mg/L of test item

Incubation duration:

6 h

Test conditions:

- Reconstituted standard based on ISO 6341;
- The aqueous medium solution sterilized by filtration (0.2 µm)
- pH=7;
- 20 +/- 1 °C;
- dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 97.5 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate

Loading of aqueous phase:

100 other: mg/L of test item

Incubation duration:

12 h

Test conditions:

- Reconstituted standard based on ISO 6341;
- The aqueous medium solution sterilized by filtration (0.2 µm)
- pH=7;
- 20 +/- 1 °C;
- dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 97.7 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate

Loading of aqueous phase:

100 other: mg/L of test item

Incubation duration:

24 h

Test conditions:

- Reconstituted standard based on ISO 6341;
- The aqueous medium solution sterilized by filtration (0.2 µm)
- pH=7;
- 20 +/- 1 °C;
- dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 96.9 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate

Loading of aqueous phase:

100 other: mg/L of test item

Incubation duration:

72 h

Test conditions:

- Reconstituted standard based on ISO 6341;
- The aqueous medium solution sterilized by filtration (0.2 µm)
- pH=7;
- 20 +/- 1 °C;
- dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 98.6 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate

Loading of aqueous phase:

100 other: mg/L of test item

Incubation duration:

168 h

Test conditions:

- Reconstituted standard based on ISO 6341;
- The aqueous medium solution sterilized by filtration (0.2 µm)
- pH=7;
- 20 +/- 1 °C;
- dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 54.1 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate; Calcium

Loading of aqueous phase:

10 g/L

Incubation duration:

0 h

Test conditions:

- Purified water adjusted to pH 2;
- 37 +/- 1°C;
- Dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 98.1 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate; Calcium

Loading of aqueous phase:

10 g/L

Incubation duration:

0.5 h

Test conditions:

- Purified water adjusted to pH 2;
- 37 +/- 1°C;
- Dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 99.3 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate; Calcium

Loading of aqueous phase:

10 g/L

Incubation duration:

2 h

Test conditions:

- Purified water adjusted to pH 2;
- 37 +/- 1°C;
- Dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 97.8 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate; Calcium

Loading of aqueous phase:

10 g/L

Incubation duration:

4 h

Test conditions:

- Purified water adjusted to pH 2;
- 37 +/- 1°C;
- Dark conditions.

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

ca. 97.5 other: Total recovery (%)

Element analysed:

Sodium; Potassium; Sulphate; Calcium

Loading of aqueous phase:

10 g/L

Incubation duration:

6 h

Test conditions:

- Purified water adjusted to pH 2;
- 37 +/- 1°C;
- Dark conditions.

2-RESULTS

2.1-TRANSFORMATION/DISSOLUTION AT PH 7

2.1.1-ION CHROMATOGRAPHY

The mean concentrations (mg/L, corrected for matrix blank), concentration per unit mass (mg/kg) and as a percentage recovery for the sodium, potassium and sulphate analyses are shown in the following tables

Sodium

Sample	Meanconcentration (mg/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 2hr	6.9337	68043.8	6.80
SPL 2 2hr	7.1597	65624.8	6.56
SPL 3 2hr	6.6097	67791.5	6.78
SPL 1 6hr	7.3312	71944.7	7.19
SPL 2 6hr	7.6312	69946.5	7.00
SPL 3 6hr	6.5822	67509.4	6.75
SPL 1 12hr	7.2342	70992.8	7.10
SPL 2 12hr	7.2722	66656.0	6.67
SPL 3 12hr	6.5552	67232.5	6.72
SPL 1 24hr	7.2432	71081.1	7.11
SPL 2 24hr	7.6817	70409.4	7.04
SPL 3 24hr	6.9537	71319.7	7.13
SPL 1 72hr	6.8797	67513.9	6.75
SPL 2 72hr	6.5607	60134.4	6.01
SPL 3 72hr	6.1462	63037.6	6.30
SPL 1 168hr	7.6570	75142.0	7.51
SPL 2 168hr	6.8207	62517.6	6.25
SPL 3 168hr	6.6382	68083.8	6.81

 

Potassium

Sample	Meanconcentration (mg/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 2hr	33.8808	332491	33.25
SPL 2 2hr	35.8413	328518	32.85
SPL 3 2hr	32.0138	328347	32.83
SPL 1 6hr	34.0973	334616	33.46
SPL 2 6hr	35.8568	328660	32.87
SPL 3 6hr	32.1033	329265	32.93
SPL 1 12hr	34.0898	334542	33.45
SPL 2 12hr	35.8863	328931	32.89
SPL 3 12hr	32.0808	329034	32.90
SPL 1 24hr	34.0133	333791	33.38
SPL 2 24hr	35.8743	328821	32.88
SPL 3 24hr	32.1443	329686	32.97
SPL 1 72hr	34.2493	336107	33.61
SPL 2 72hr	35.8843	328912	32.89
SPL 3 72hr	32.0253	328465	32.85
SPL 1 168hr	36.2023	355273	35.53
SPL 2 168hr	35.8283	328399	32.84
SPL 3 168hr	32.7953	336362	33.64

 

Sulphate

Sample	Meanconcentration (mg/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 2hr	58.8786	577807	57.78
SPL 2 2hr	62.9819	577286	57.73
SPL 3 2hr	55.2756	566929	56.69
SPL 1 6hr	59.2475	581428	58.14
SPL 2 6hr	62.9803	577271	57.73
SPL 3 6hr	55.6540	570811	57.08
SPL 1 12hr	59.1072	580051	58.01
SPL 2 12hr	62.6056	573837	57.38
SPL 3 12hr	55.9918	574275	57.43
SPL 1 24hr	58.9411	578421	57.84
SPL 2 24hr	62.5150	573003	57.30
SPL 3 24hr	55.7930	572236	57.22
SPL 1 72hr	59.1190	580167	58.02
SPL 2 72hr	61.9963	568252	56.83
SPL 3 72hr	55.9563	573911	57.39
SPL 1 168hr	59.2752	581700	58.17
SPL 2 168hr	61.6852	565400	56.54
SPL 3 168hr	56.9305	583903	58.39

2.1.2-ICP-MS (confirmatory analysis)

From the analysis of the sample solutions, the counts per second for each analyte were interpolated from the respective calibrations to give the concentration of analyte (mg/L). The mean concentrations (mg/L), concentration per unit mass (mg/kg) and as a percentage recovery for the sodium, potassium and sulphate analyses are shown in the following tables:

Sodium

Sample	Meanconcentration (mg/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 2hr	7.17	70345	7.03
SPL 2 2hr	8.59	78709	7.87
SPL 3 2hr	7.44	76328	7.63
SPL 1 6hr	8.24	80848	8.08
SPL 2 6hr	7.44	68186	6.82
SPL 3 6hr	7.41	75967	7.60
SPL 1 12hr	7.78	76379	7.64
SPL 2 12hr	7.65	70107	7.01
SPL 3 12hr	9.11	93424	9.34
SPL 1 24hr	8.36	82054	8.21
SPL 2 24hr	9.12	83582	8.36
SPL 3 24hr	8.47	86842	8.68
SPL 1 72hr	10.2	100362	10.0
SPL 2 72hr	8.87	81275	8.13
SPL 3 72hr	8.39	86031	8.60
SPL 1 168hr	10.1	99181	9.92
SPL 2 168hr	8.53	78216	7.82
SPL 3 168hr	8.08	82886	8.29

 

Potassium

Sample	Meanconcentration (mg/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 2hr	37.2	364925	36.5
SPL 2 2hr	32.4	297010	29.7
SPL 3 2hr	30.8	315478	31.6
SPL 1 6hr	32.1	314940	31.5
SPL 2 6hr	34.1	312152	31.2
SPL 3 6hr	29.8	305441	30.5
SPL 1 12hr	31.7	310825	31.1
SPL 2 12hr	34.3	314660	31.5
SPL 3 12hr	30.3	310682	31.1
SPL 1 24hr	34.3	336110	33.6
SPL 2 24hr	35.3	324221	32.4
SPL 3 24hr	31.4	321639	32.2
SPL 1 72hr	34.6	339226	33.9
SPL 2 72hr	35.5	325232	32.5
SPL 3 72hr	32.5	333472	33.4
SPL 1 168hr	34.9	342158	34.2
SPL 2 168hr	34.8	318893	31.9
SPL 3 168hr	31.6	323864	32.4

 

Sulphate

Sample	Meanconcentration (mg/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 2hr	52.0	509811	51.0
SPL 2 2hr	57.1	523100	52.3
SPL 3 2hr	52.2	535301	53.5
SPL 1 6hr	56.7	556379	55.6
SPL 2 6hr	61.3	561922	56.2
SPL 3 6hr	46.0	471789	47.2
SPL 1 12hr	50.4	495081	49.5
SPL 2 12hr	59.0	541034	54.1
SPL 3 12hr	47.7	488835	48.9
SPL 1 24hr	51.7	507445	50.7
SPL 2 24hr	61.1	559708	56.0
SPL 3 24hr	52.6	539425	53.9
SPL 1 72hr	55.6	545592	54.6
SPL 2 72hr	64.2	588460	58.9
SPL 3 72hr	49.8	511104	51.1
SPL 1 168hr	55.6	545856	54.6
SPL 2 168hr	61.0	559220	55.9
SPL 3 168hr	50.7	519631	52.0

 

2.1.3-DISCUSSION

The definitive results obtained by ion chromatography were assessed for reproducibility from the triplicate flasks for all time points. This demonstrated mean relative standard deviation of 4.06% for sodium, 1.50% for potassium, 0.99% forsulphate and therefore the test was considered to be consistent across the flasks at all the time points.

Comparison of the results obtained in the test with the theoretical concentrations from the Certificate of Analysis (sodium 66.0 g/kg, potassium 313 g/kg,sulphate564 g/kg), demonstrates that the test item was essentially fully dissolved in the test media at all time points.

The pH of the test solutions was stable (<0.2 pH unit deviation) over the duration of the study.  

The dissolved oxygen level in all the test solutions was greater than 70% saturation (6.0 mg/L) and thus satisfied the guideline.

The calcium content of the solutions was not determined since there was a significant amount of calcium present in the test medium, and therefore it was considered that it would not be possible to obtain reliable results.

The ICP-MS confirmatory analysis demonstrated no significant difference in the levels of sodium, potassium andsulphate in the samples solutions.

The study results reported from the ion chromatography analysis were considered acceptable.

 

2.2-TRANSFORMATION/DISSOLUTION AT PH 2

2.2.1-ION CHROMATOGRAPHY

Sodium

Sample	Meanconcentration (g/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	0.236	2.31 x 10^4	2.31
SPL 2 0hr	0.276	2.65 x 10^4	2.66
SPL 3 0hr	0.285	2.75 x 10^4	2.75
SPL 1 0.5hr	0.537	5.26 x 10^4	5.26
SPL 2 0.5hr	0.546	5.26 x 10^4	5.26
SPL 3 0.5hr	0.537	5.19 x 10^4	5.19
SPL 1 2hr	0.590	5.78 x 10^4	5.78
SPL 2 2hr	0.534	5.14 x 10^4	5.14
SPL 3 2hr	0.547	5.29 x 10^4	5.29
SPL 1 4hr	0.528	5.18 x 10^4	5.18
SPL 2 4hr	0.550	5.30 x 10^4	5.30
SPL 3 4hr	0.559	5.40 x 10^4	5.40
SPL 1 6hr	0.541	5.30 x 10^4	5.30
SPL 2 6hr	0.535	5.15 x 10^4	5.15
SPL 3 6hr	0.541	5.23 x 10^4	5.23

 

Potassium

Sample	Meanconcentration (g/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	1.69	1.66 x 10^5	16.6
SPL 2 0hr	1.97	1.90 x 10^5	19.0
SPL 3 0hr	1.88	1.81 x 10^5	18.1
SPL 1 0.5hr	3.36	3.29 x 10^5	32.9
SPL 2 0.5hr	3.42	3.30 x 10^5	33.0
SPL 3 0.5hr	3.40	3.29 x 10^5	32.9
SPL 1 2hr	3.48	3.41 x 10^5	34.1
SPL 2 2hr	3.40	3.28 x 10^5	32.8
SPL 3 2hr	3.40	3.28 x 10^5	32.8
SPL 1 4hr	3.34	3.27 x 10^5	32.7
SPL 2 4hr	3.42	3.29 x 10^5	32.9
SPL 3 4hr	3.38	3.27 x 10^5	32.7
SPL 1 6hr	3.33	3.26 x 10^5	32.6
SPL 2 6hr	3.43	3.30 x 10^5	33.0
SPL 3 6hr	3.36	3.25 x 10^5	32.5

 

Calcium

Sample	Meanconcentration (g/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	2.60 x 10^-2	2.55 x 10^3	0.255
SPL 2 0hr	2.37 x 10^-2	2.28 x 10^3	0.228
SPL 3 0hr	3.04 x 10^-2	2.94 x 10^3	0.294
SPL 1 0.5hr	3.47 x 10^-2	3.40 x 10^3	0.340
SPL 2 0.5hr	3.41 x 10^-2	3.29 x 10^3	0.329
SPL 3 0.5hr	3.24 x 10^-2	3.14 x 10^3	0.314
SPL 1 2hr	3.71 x 10^-2	3.64 x 10^3	0.364
SPL 2 2hr	3.49 x 10^-2	3.36 x 10^3	0.336
SPL 3 2hr	3.33 x 10^-2	3.22 x 10^3	0.322
SPL 1 4hr	3.32 x 10^-2	3.25 x 10^3	0.325
SPL 2 4hr	3.48 x 10^-2	3.35 x 10^3	0.335
SPL 3 4hr	3.37 x 10^-2	3.25 x 10^3	0.325
SPL 1 6hr	3.08 x 10^-2	3.01 x 10^3	0.301
SPL 2 6hr	3.44 x 10^-2	3.32 x 10^3	0.332
SPL 3 6hr	3.47 x 10^-2	3.35 x 10^3	0.335

 

Sulphate

Sample	Meanconcentration (g/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	3.18	3.11 x 10^5	31.1
SPL 2 0hr	3.65	3.52 x 10^5	35.2
SPL 3 0hr	3.51	3.39 x 10^5	33.9
SPL 1 0.5hr	6.08	5.96 x 10^5	59.6
SPL 2 0.5hr	6.20	5.97 x 10^5	59.7
SPL 3 0.5hr	6.15	5.95 x 10^5	59.5
SPL 1 2hr	6.31	6.18 x 10^5	61.8
SPL 2 2hr	6.19	5.96 x 10^5	59.6
SPL 3 2hr	6.16	5.95 x 10^5	59.5
SPL 1 4hr	6.05	5.93 x 10^5	59.3
SPL 2 4hr	6.19	5.96 x 10^5	59.6
SPL 3 4hr	6.14	5.94 x 10^5	59.4
SPL 1 6hr	6.04	5.92 x 10^5	59.2
SPL 2 6hr	6.16	5.93 x 10^5	59.3
SPL 3 6hr	6.11	5.91 x 10^5	59.1

 

2.2.2-ICP-MS (confirmatory analysis)

From the analysis of the sample solutions, the counts per second for each analyte were interpolated from the respective calibrations to give the concentration of analyte (mg/L). The mean concentrations (g/L), concentration per unit mass (mg/kg) and percentage recovery for the sodium, potassium, calcium and sulphate analyses are shown in the following tables:

Sodium

Sample	Meanconcentration (g/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	0.401	3.93 x 10^4	3.93
SPL 2 0hr	0.547	5.27 x 10^4	5.27
SPL 3 0hr	0.369	3.56 x 10^4	3.56
SPL 1 0.5hr	0.596	5.84 x 10^4	5.84
SPL 2 0.5hr	1.04	1.00 x 10^5	10.0
SPL 3 0.5hr	0.917	8.87 x 10^4	8.87
SPL 1 2hr	0.707	6.92 x 10^4	6.92
SPL 2 2hr	1.01	9.78 x 10^4	9.78
SPL 3 2hr	0.971	9.39 x 10^4	9.39
SPL 1 4hr	0.663	6.50 x 10^4	6.50
SPL 2 4hr	1.11	1.07 x 10^5	10.7
SPL 3 4hr	0.844	8.16 x 10^4	8.16
SPL 1 6hr	0.721	7.07 x 10^4	7.07
SPL 2 6hr	1.06	1.02 x 10^5	10.2
SPL 3 6hr	0.963	9.31 x 10^4	9.31

 

Potassium

Sample	Meanconcentration (g/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	2.10	2.06 x 10^5	20.6
SPL 2 0hr	2.73	2.63 x 10^5	26.3
SPL 3 0hr	2.70	2.61 x 10^5	26.1
SPL 1 0.5hr	3.75	3.67 x 10^5	36.7
SPL 2 0.5hr	4.82	4.64 x 10^5	46.4
SPL 3 0.5hr	4.89	4.73 x 10^5	47.3
SPL 1 2hr	3.82	3.75 x 10^5	37.5
SPL 2 2hr	4.57	4.40 x 10^5	44.0
SPL 3 2hr	4.93	4.77 x 10^5	47.7
SPL 1 4hr	3.77	3.70 x 10^5	37.0
SPL 2 4hr	5.24	5.05 x 10^5	50.5
SPL 3 4hr	5.02	4.85 x 10^5	48.5
SPL 1 6hr	3.94	3.86 x 10^5	38.6
SPL 2 6hr	4.72	4.55 x 10^5	45.5
SPL 3 6hr	4.99	4.82 x 10^5	48.2

 

Calcium

Sample	Meanconcentration (g/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	2.51 x 10^-2	2.46 x 10^3	0.246
SPL 2 0hr	2.44 x 10^-2	2.35 x 10^3	0.235
SPL 3 0hr	2.48 x 10^-2	2.40 x 10^3	0.240
SPL 1 0.5hr	3.28 x 10^-2	3.22 x 10^3	0.322
SPL 2 0.5hr	4.07 x 10^-2	3.93 x 10^3	0.393
SPL 3 0.5hr	3.61 x 10^-2	3.49 x 10^3	0.349
SPL 1 2hr	3.63 x 10^-2	3.56 x 10^3	0.356
SPL 2 2hr	3.90 x 10^-2	3.76 x 10^3	0.376
SPL 3 2hr	3.47 x 10^-2	3.35 x 10^3	0.335
SPL 1 4hr	3.31 x 10^-2	3.25 x 10^3	0.325
SPL 2 4hr	3.73 x 10^-2	3.60 x 10^3	0.360
SPL 3 4hr	3.10 x 10^-2	3.00 x 10^3	0.300
SPL 1 6hr	3.48 x 10^-2	3.41 x 10^3	0.341
SPL 2 6hr	4.24 x 10^-2	4.09 x 10^3	0.409
SPL 3 6hr	3.51 x 10^-2	3.39 x 10^3	0.339

 

Sulphate

Sample	Meanconcentration (mg/L)	Meanconcentration (mg/kg)	Recovery (%)
SPL 1 0hr	2.60 x 10^3	2.55 x 10^5	25.5
SPL 2 0hr	3.34 x 10^3	3.27 x 10^5	32.7
SPL 3 0hr	3.40 x 10^3	3.33 x 10^5	33.3
SPL 1 0.5hr	4.68 x 10^3	4.58 x 10^5	45.8
SPL 2 0.5hr	5.58 x 10^3	5.47 x 10^5	54.7
SPL 3 0.5hr	5.46 x 10^3	5.35 x 10^5	53.5
SPL 1 2hr	4.52 x 10^3	4.42 x 10^5	44.2
SPL 2 2hr	5.65 x 10^3	5.54 x 10^5	55.4
SPL 3 2hr	5.66 x 10^3	5.55 x 10^5	55.5
SPL 1 4hr	4.65 x 10^3	4.56 x 10^5	45.6
SPL 2 4hr	5.44 x 10^3	5.33 x 10^5	53.3
SPL 3 4hr	5.47 x 10^3	5.36 x 10^5	53.6
SPL 1 6hr	4.57 x 10^3	4.48 x 10^5	44.8
SPL 2 6hr	5.76 x 10^3	5.64 x 10^5	56.4
SPL 3 6hr	6.16 x 10^3	6.04 x 10^5	60.4

 

2.2.3-DISCUSSION

The definitive results obtained by ion chromatography were assessed for reproducibility from the triplicate flasks for all time points. This demonstrated mean relative standard deviations of 3.89% for sodium, 2.07% for potassium, 6.13% for calcium and 1.80% for sulphate. Sodium, potassium and sulphate analysis were considered to be consistent (<5% RSD) across the flasks at all the time points. The higher variability in the calcium results was considered to be due to lower concentrations present in the sample solutions.

Comparison of the results obtained in the test with the theoretical concentrations from the Certificate of Analysis (sodium 66.0 g/kg, potassium 313 g/kg, sulphate 564 g/kg, calcium 0.285 g/kg), demonstrates that the test item was essentially fully dissolved in the test media after 30 minutes.

Although the ICP-MS confirmatory analysis demonstrated minor differences in reported concentrations, the analysis served to confirm the analyte species and approximate levels in the sample solutions. 

For the analysis by IC, matrix blanks were demonstrated generally low and inconsistent peak areas, therefore it was not considered necessary to correct the sample results for the contribution from the matrix blanks. In the ICP-MS analysis, matrix blanks were significant for sulphur(sulphate analysis) and therefore matrix blank corrections were applied to all ICP-MS analysis.

At each time point from 0.5 hour onwards, all of the samples were observed to be clear colorless and free from excess undissolved test item.

The pH of all the test solutions increased after addition of test item to pH 2.3 and remained stable throughout the duration of the test.   

The dissolved oxygen level in all the test solutions was greater than 70% saturation (6.0 mg/L) and thus satisfied the guideline.

 

 

Conclusions:

The transformation/dissolution of the test item in reconstituted standard water based on ISO6341 at pH 7 at 100 mg/L at 20± 1 °C has been determined by ion chromatography. The results demonstrate that the test item is effectively completely transformed/dissolved within 2 hours.
The transformation/dissolution of the test item in purified water adjusted to pH 2 at 10 g/L at 37 °C ± 1 °C has been determined by ion chromatography. The results demonstrate that the test item is effectively completely transformed/dissolved within 30 minutes.

Executive summary:

The transformation/dissolution of the test item has been determined using a GLP-compliant procedure designed to be compatible with Annex 10, Guidance on Transformation/Dissolution of Metals and Metal Compounds in Aqueous Media, OECD Environment, Health and Safety Publications, Series on Testing and Assessment, No.29, Environment Directorate,Organisationfor Economic Co-operation and Development, 23 July 2001.

The results are summarized below:

The transformation/dissolution of the test item in reconstituted standard water based on ISO6341 at pH 7 at 100 mg/L at 20 ± 1 °C has been determined by ion chromatography. The results of the analysis by ion chromatography are shown in the following table:

Shaking time at 20°C (hours)	Sodium (g/kg)	Potassium (g/kg)	Sulphate (g/kg)	Residue (g/kg)	Total recovery (%)
2	67.2	330	574	-	97.1
6	69.8	331	577	-	97.7
12	68.3	331	576	-	97.5
24	70.9	331	575	-	97.7
72	63.6	331	574	-	96.9
168	68.6	340	577	None detected	98.6

The results demonstrate that the test item is effectively completely transformed/dissolved within 2 hours into  Na+, K+, SO4-- ions when added in ISO 6341 medium at pH 7 and  20°C (calcium was not analysed because its level in EXP was too low compared to the concentration of calcium in the tested medium).

The transformation/dissolution of the test item in pH 2 purified water at 10 g/L at 37 °C ± 1 °C has been determined by ion chromatography. The results of the analysis by ion chromatography are shown in the following table:

Shaking time at 37°C (hours)	Sodium (g/kg)	Potassium (g/kg)	Calcium (g/kg)	Sulphate (g/kg)	Residue (g/kg)	Total recovery (%)
0	25.7	179	2.59	334	-	54.1
0.5	52.4	329	3.28	596	-	98.1
2	54.0	332	3.41	603	-	99.3
4	52.9	328	3.29	594	-	97.8
6	52.3	327	3.23	592	4.0	97.4

The results demonstrate that the test item is effectively completely transformed/dissolved within 30 minutes into Na+, K+, Ca++, SO4-- ions when added in purified water at pH 2 and  37°C.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05-May-2010 to 16-Jun-2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: 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.

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of Signature: November 12, 2008

Type of method:

flask method

Remarks:

EXAMPLE: The determination was carried out using the flask method, Method A6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Water solubility:

445.5 g/L

Temp.:

20 °C

pH:

5.23

The saturation concentration of Sodium Sulphate at room temperature was estimated by a simplified flask method in the preliminary test to be higher than 10^-2g/L. Therefore, the flask shaking test was performed.

 

After a shaking time of 24 hours, 48 hours and 72 hours, respectively, at 30 °C, the samples were equilibrated for another 24 hours at 20 °C. Afterwards, the samples were centrifuged, diluted and analyzed by IC. The water solubility of Sodium Sulphate at 20.0 °C was determined to be 445.47 g/L. The measured results differ by less than 15%. Therefore, the study is considered to be valid. The results of the individual measurements of the main test are summarized inTable 2. The tabulated values represent rounded results, which were obtained by calculation using the exact raw data.

 

 

A typical chromatogram of a standard solution is given in Figure 1. A typical chromatogram of a sample solution after 72 hours of incubation is shown in Figure 2. An IC chromatogram of a blank solution is shown in Figure 3. The calibration curve and data are shown in Figure 4 and in Table 3. The r² fit was 0.9999 (optimum 1.0000). This reflects the linearity of the IC-system within the calibration range of 3.324 µg/mL to 99.72 µg/mL of the test item.

Table 1       Data of the Performance of the Water Solubility Test

Sample Solution No.		1		2		3		4		5		6
Weighed sample of the test item [g]		7.883		7.340		8.485		7.495		8.007		7.647
Added volume of water [mL]		10		10		10		10		10		10
Agitation time at 30 °C [hours]		72		72		48		48		24		24
Equilibration time at 20 °C [hours]		24		24		24		24		24		24
pH value of test item solution		5.16		5.17		5.21		5.24		5.31		5.31
Dilution factor before quantification		10000		10000		10000		10000		10000		10000

 

 

Table 2       Results of the Water Solubility of Sodium Sulphate

Sample No.		Shaking time at 30 °C		Concentration analyzed		Concentration calculated		Water solubility calculated (rounded)
				[mg/L]		[g/L]		[g/L]
1		72		45.000		450.001		445.47 SD = 14.81
2			45.788		457.876
3		48		44.821		448.206
4			45.075		450.754
5		24		44.994		449.935
6			41.603		416.031

 

The saturation mass concentration is calculated from the bold values

 

SD = standard deviation

 

 

Conclusions:

Interpretation of results : very soluble (> 10000 mg/L)
During this study the water solubility of Sodium Sulphate was determined and found to be 445.47 g/L at 20.0 °C and a pH of 5.23 using the flask shaking method.

Executive summary:

During this study the water solubility of Sodium Sulphate was determined. Vessels containing water and test item were shaken for 24 hours, 48 hours and 72 hours, respectively, at 30 °C. Afterwards the samples were equilibrated for another 24 hours at 20.0 °C. After dilution with water the concentrations in the aqueous solutions were determined by an IC-method.

 

The water solubility of Sodium Sulphate was determined to be

 

445.5 g/L at 20.0 °C and a pH of 5.23

 

using the flask shaking method.

 

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-04-12 to 2010-04-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Conducted to current accepted guidelines. No GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

In place of centrifugation, the solution was filtered with filter paper prior to determination of the mass concentration of the substance in aqueous solution.

GLP compliance:

no

Type of method:

flask method

Water solubility:

2.4 g/L

Temp.:

20 °C

pH:

7.7

Details on results:

In the first preliminary test, the sample remained essentially undissolved. At the end of the second preliminary test, the sample appeared totally dissolved. From the results of the preliminary testing, that the water solubility of calcium sulphate dihydrate was between 1 and 10 g per litre of water. In the definitive test, no tendency to concentration increase could be detected, so the average value of the 3 samples was taken to determine the solubility. It was observed that magnetic stirring increased the temperature slightly. During pH measurement, the temperature was measured from the filtrates allowing direct measurement during magnetic stirring. The temperature of the samples was found to increase from 20 to 21-22°C, which was not thought to produce noticeable effects on the solubility of the test material.

  Table 1: tabulated water solubility data

Sample	Ca in g/L		SO4 in g/L		pH
	Measurements	Mean value	Measurements	Mean value
Flask 1	0.724	0.725	1.911	1.9	7.7
	0.729		1.913		7.7
	0.723		1.9		7.6
Flask 2	0.731	0.728	1.873	1.86	7.7
	0.723		1.854		7.6
	0.729		1.881		7.6
Flask 3	0.724	0.723	1.735	1.73	7.7
	0.724		1.724		7.6
	0.721		1.719		7.7

The water solubility was determined from the concentration of calcium as the value calculated by using the solubility of SO4 instead of Ca produces a slightly higher value, this is due to a small interference by small quantities of sodium, potassium, magnesium sulfates explaining this small overestimation.

Conclusions:

Interpretation of results : soluble (1000-10000 mg/L)
The water solubility of CaSO4 was determined to be 2.4 g/L at 20°C and with a pH value of 7.7.

Reference 4

Endpoint:

water solubility

Type of information:

other: handbook

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Data have been taken from many sources, including both compilations and the primary literature - where conflicts were found, the value deemed most reliable was chosen. The reference was peer-reviewed. In addition, the reference sources are indicated although not leading to sufficient information on the material & method used.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Method followed unknown; data from handbook.

GLP compliance:

not specified

Water solubility:

120 g/L

Remarks on result:

other: pH and T° not provided

Value given in the reference: 1 g/8.3 mL No data on temperature.

Conclusions:

Interpretation of results : very soluble (> 10000 mg/L)
The water solubility of potassium sulfate is 120 g/L (no temperature).

Reference 5

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

No method specified

GLP compliance:

not specified

Key result

Water solubility:

120 g/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: pH not provided

Description of key information

The transformation/dissolution of the target substance "Sulfates of potassium, sodium and calcium, by-product from fermentation" in reconstituted standard water (ISO6341) at pH 7, at 100 mg/L, and at 20± 1 °C has been determined by ion chromatography. The results demonstrate that the test item is effectively completely transformed/dissolved within 2 hours into sulfate anions and potassium, sodium and calcium cations.

The water solubility of "Sulfates of potassium, sodium and calcium, by-product from fermentation" is 2.4 g/L at 20°C (pH=7.7), which is the lowest water solubility measured on the 3 source substances, Potassium sulfate (CAS 7778 -80 -5), Sodium sulfate (CAS 7757 -82-6) and Calcium sulfate  (CAS 7778-18-9).

.

Key value for chemical safety assessment

Water solubility:

2.4 g/L

at the temperature of:

20 °C

Additional information

The transformation/dissolution of the target substance "Sulfates of potassium, sodium and calcium, by-product from fermentation" in reconstituted standard water (ISO6341), at pH 7, at 100 mg/L and at 20± 1°C, has been determined according to the Guidance on Transformation/Dissolution of Metals and Metal Compounds in Aqueous Media (OECD Series on Testing and Assessment,  No.29, 23 July 2001). The results demonstrate that the test item is effectively completely transformed/dissolved within 2 hours into sulfate anions and potassium, sodium and calcium cations, measured by by ion chromatography.

As the 3 source substances, Potassium sulfate (CAS 7778-80-5), Sodium sulfate (CAS 7757-82-6) and Calcium sulfate  (CAS 7778-18-9) are also completely dissociated in aqueous media into sulfate anions and the respective cations, then the water solubility of the target substance can be assessed through the water solubility of the source substances which are : 120g/L at 25°C (pH not specified) for potassium sulfate, 445 g/L at 20°C (pH=5.23) for sodium sulfate and 2.4 g/L at 20°C (pH=7.7) for calcium sulfate. The water solubility of "Sulfates of potassium, sodium and calcium, by-product from fermentation" is 2.4 g/L at 20°C (pH=7.7), which is the lowest water solubility observed amongst the 3 source substances.