Chrome tin orchid cassiterite

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-04-16 to 2015-10-06

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

Version / remarks:

2001

GLP compliance:

yes (incl. QA statement)

Remarks:

2016-05-31

Type of method:

other: transformation / dissolution

Key result

Type of test:

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

Mean dissolved conc.:

0.046 µg/L

Element analysed:

Cr

Loading of aqueous phase:

1 mg/L

Incubation duration:

672 h

Test conditions:

pH 6, agitation at 100 rpm, 20.4 ± 0.2 °C

Remarks on result:

other: SD: ± 0.022 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

< 0.028 µg/L

Element analysed:

Cr

Loading of aqueous phase:

1 mg/L

Incubation duration:

168 h

Test conditions:

pH 6, agitation at 100 rpm, 20.4 ± 0.2 °C

Remarks on result:

other: at least

Type of test:

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

Mean dissolved conc.:

< 0.008 µg/L

Element analysed:

Cr

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH 6, agitation at 100 rpm, 20.4 ± 0.2 °C

Remarks on result:

other: At least

Key result

Type of test:

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

Mean dissolved conc.:

0.352 µg/L

Element analysed:

Sn

Loading of aqueous phase:

1 mg/L

Incubation duration:

672 h

Test conditions:

pH 6, agitation at 100 rpm, 20.4 ± 0.2 °C

Remarks on result:

other: SD: ± 0.055 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

0.463 µg/L

Element analysed:

Sn

Loading of aqueous phase:

1 mg/L

Incubation duration:

168 h

Test conditions:

pH 6, agitation at 100 rpm, 20.4 ± 0.2 °C

Remarks on result:

other: SD: ± 0.141 µg/L

Type of test:

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

Mean dissolved conc.:

0.467 µg/L

Element analysed:

Sn

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH 6, agitation at 100 rpm, 20.4 ± 0.2 °C

Remarks on result:

other: SD: ± 0.089 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

0.052 µg/L

Element analysed:

Cr

Loading of aqueous phase:

1 mg/L

Incubation duration:

672 h

Test conditions:

pH 8, agitation at 100 rpm, 21.2 ± 0.2 °C

Remarks on result:

other: SD: ± 0.001 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

0.042 µg/L

Element analysed:

Cr

Loading of aqueous phase:

1 mg/L

Incubation duration:

168 h

Test conditions:

pH 8, agitation at 100 rpm, 21.2 ± 0.2 °C

Remarks on result:

other: SD: ± 0.004 µg/L

Type of test:

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

Mean dissolved conc.:

0.028 µg/L

Element analysed:

Cr

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH 8, agitation at 100 rpm, 21.2 ± 0.2 °C

Remarks on result:

other: SD: ± 0.009 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

4.32 µg/L

Element analysed:

Sn

Loading of aqueous phase:

1 mg/L

Incubation duration:

672 h

Test conditions:

pH 8, agitation at 100 rpm, 21.2 ± 0.2 °C

Remarks on result:

other: SD: ± 2.293 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

2.873 µg/L

Element analysed:

Sn

Loading of aqueous phase:

1 mg/L

Incubation duration:

168 h

Test conditions:

pH 8, agitation at 100 rpm, 21.2 ± 0.2 °C

Remarks on result:

other: SD: ± 0.766 µg/L

Type of test:

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

Mean dissolved conc.:

0.978 µg/L

Element analysed:

Sn

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH 8, agitation at 100 rpm, 21.2 ± 0.2 °C

Remarks on result:

other: SD: ± 0.081 µg/L

Details on results:

Temperature:
The mean temperature was 20.4 ± 0.2 °C during the test with 1 mg/L loading at pH 6. The mean temperature during the test at pH 8 was 21.2 ± 0.2 °C.

pH:
In solutions containing 1 mg/L of the test item at pH 6 and pH 8 as well as in method blanks (BW), the pHs were in the range of 5.8 – 6.4 and 7.6 – 8.2, respectively.

Mass balance
Most of the measured chromium concentrations were below LOD/LOQ (pH 6: 0.157 / 0.471 µg Cr/L; pH 8: 0.335 / 1.006 µg Cr/L) of the ICP-OES measurement. Only in vessel 4 (pH 6) all measured concentrations in the different fractions were above LOQ. The recovery in vessel 4 was 96.7 %. In the other vessels the recovery is clearly below 100 ± 15 %, indicating that aqua regia is not sufficient for a complete dissolution of the test item. The latter fact is expected for inorganic pigments.

Recoveries of fortified samples Chromium

(values were rounded, internal calculations were performedwith more digits)

	Measured Cr conc. [μg/L]	Calculated nominal Cr conc. after addition [μg/L]	Recovery [μg Cr/L]	Recovery [%]
1st measurement series 1 mL of sample + 2 mL of 5 μg M/L
Vessel 4, sample a after 2h	<LOD	3.333	3.284	98.5
Vessel 4, sample b after 6h	<LOD	3.333	3.307	99.2
Vessel 4, sample a after 24h	<LOD	3.333	3.303	99.1
2nd measurement series1 mL of sample + 2 mL of 5 μg M/L
Vessel 4, sample a after 4d	0.078	3.359	3.479	103.6
Vessel 4, sample a after 7d	0.033	3.344	3.556	106.3
Vessel 4, sample a after 14d	<LOQ	3.333	3.830	114.9
3rd measurement series1 mL of sample + 2 mL of 5 μg M/L
Vessel 4, sample a after 21d	<LOQ	3.333	3.603	108.1
Vessel 4, sample a after 28d	0.034	3.345	3.600	107.6
Vessel 4, sample a after 6h	<LOD	3.333	3.521	105.6
4th measurement series1 mL of sample + 2 mL of 5 μg M/L
Vessel 1, sample a after 2h	0.019	3.340	3.494	104.6
Vessel 1, sample a after 6h	0.020	3.340	3.574	107.0
Vessel 1, sample a after 1d	0.037	3.346	4.071	121.7
Vessel 1, sample a after 4d	0.053	3.351	3.544	105.8
Vessel 1, sample a after 7d	0.105	3.368	3.714	110.3
Vessel 1, sample a after 14d	0.060	3.353	3.579	106.7
Vessel 1, sample a after 21d	0.062	3.354	3.761	112.1
Vessel 1, sample a after 28d	0.051	3.350	3.589	107.1
5th measurement series1 mL of sample + 4 mL of 5 μg M/L
Method blank vessel 2 sample a after 2h	<LOD	4.000	4.375	109.4
Method blank vessel 2 sample a after 1d	<LOD	4.000	4.366	109.1
Method blank vessel 2 sample a after 7d	<LOD	4.000	4.413	110.3
Method blank vessel 2 sample a after 28d	<LOD	4.000	4.366	109.2
6th measurement series1 mL of sample + 4 mL of 5 μg M/L
sample from vessel 4 for mass balance	1.474	4.295	3.999	93.1
7th measurement series1 mL of sample + 4 mL of 25 μg M/L
sample from vessel 1	<LOQ	20.000	19.337	96.7

 

 

Recoveries of fortified samples Tin

(values were rounded, internal calculations were performedwith more digits)

	Measured Sn conc. [μg/L]	Calculated nominal Sn conc. after addition [μg/L]	Recovery [μg Sn/L]	Recovery [%]
1st measurement series 1 mL of sample + 2 mL of 5 μg M/L
Vessel 4, sample a after 2h	0.074	3.358	3.418	101.8
Vessel 4, sample b after 6h	0.245	3.415	3.504	102.6
Vessel 4, sample a after 24h	0.240	3.413	3.562	104.4
2nd measurement series1 mL of sample + 2 mL of 5 μg M/L
Vessel 4, sample a after 4d	0.372	3.457	3.598	104.1
Vessel 4, sample a after 7d	0.332	3.444	3.589	104.2
Vessel 4, sample a after 14d	0.356	3.452	4.504	130.5
3rd measurement series1 mL of sample + 2 mL of 5 μg M/L
Vessel 4, sample a after 21d	0.397	3.466	3.481	100.4
Vessel 4, sample a after 28d	0.432	3.477	3.517	101.2
Vessel 4, sample a after 6h	0.042	3.347	3.438	102.7
4th measurement series1 mL of sample + 2 mL of 5 μg M/L
Vessel 1, sample a after 2h	0.138	3.379	3.481	103.0
Vessel 1, sample a after 6h	0.312	3.437	3.577	104.0
Vessel 1, sample a after 1d	0.873	3.624	4.320	119.2
Vessel 1, sample a after 4d	2.219	4.073	4.206	103.3
Vessel 1, sample a after 7d	3.453	4.484	4.678	104.3
Vessel 1, sample a after 14d	2.984	4.328	4.576	105.7
Vessel 1, sample a after 21d	3.006	4.335	4.633	106.9
Vessel 1, sample a after 28d	2.922	4.307	4.544	105.5
5th measurement series1 mL of sample + 4 mL of 5 μg M/L
Method blank vessel 2 sample a after 2h	<LOD	4.000	4.137	103.4
Method blank vessel 2 sample a after 1d	<LOD	4.000	4.133	103.3
Method blank vessel 2 sample a after 7d	<LOD	4.000	4.180	104.5
Method blank vessel 2 sample a after 28d	<LOD	4.000	4.127	103.2

 

Method validation summary

Validation parameter	results	Comment
selectivity	selective wavelength and isotopes for detection and evaluation of Cr and Sn
linearity	applied calibration functions were linear	correlation factor at least 0.9996
limit of detection	Cr: ICP-MS: 0.0027 – 0.0117 μg/L ICP-OES (mass balance): 01570 – 0.3352 μg/L Sn: ICP-MS: 0.0009 – 0.0096 μg/L
limit of quantification	Cr: I CP-MS: 0.0082– 0.0350 μg/L ICP-OES (mass balance): 0.4711– 1.0057 μg/L Sn: ICP-MS: 0.0028 – 0.0288 μg/L
accuracy and precision	mean recovery for CRM TMDA-25.4: 2nd measurement series: Cr: 101.0 ± 1.6 % (n = 11) Sn: 101.5 ± 1.6 % (n = 11) 3rd measurement series: Cr: 110.8 ± 1.7 % (n = 7) Sn: 106.1 ± 0.5 % (n = 7) 4th measurement series: Cr: 108.3 ± 2.2 % (n = 7) Sn: 109.1 ± 2.0 % (n = 7) 5th measurement series: Cr: 108.6 ± 3.0 % (n = 6) Sn: 104.1 ± 0.7 % (n = 6) 6th measurement series: Cr: 99.9 ± 1.6 % (n = 3) 7th measurement series: Cr: 102.4 ± 1.5 % (n = 4)	Diluted (5 fold) to 4.8 μg Cr/L 4.76 μg Sn/L
accuracy and precision	mean recovery for CRM TMDA-25.4: 1st measurement series: Cr: 101.3 ± 2.8 % (n = 11) Sn: 101.0 ± 0.8 % (n = 11)	Diluted (10 fold) to 2.4 μg Cr/L 2.38 μg Sn/L
accuracy and precision	mean recovery for CRM TMDA-53.3 1st measurement series: Cr: 100.5 ± 1.7 % (n = 11) Sn: 102.5 ± 3.5 % (n = 11)	Diluted (5 fold) to 68.2 μg Cr/L 3.68 μg Sn/L
accuracy and precision	mean recovery for CRM TMDA-53.3 2nd measurement series: Cr: 99.9 ± 1.2 % (n = 11) Sn: 100.4 ± 1.3 % (n = 11) 3rd measurement series: Cr: 110.4 ± 1.7 % (n = 7) Sn: 106.1 ± 0.7 % (n = 7) 4th measurement series: Cr: 107.7 ± 7.2 % (n = 7) Sn: 110.0 ± 7.2 % (n = 7) 5th measurement series: Cr: 109.2 ± 4.6 % (n = 6) Sn: 104.2 ± 3.5 % (n = 6) 6th measurement series: Cr: 102.3 ± 1.0 % (n = 3) 7th measurement series: Cr: 100.8 ± 0.2 % (n = 4)	Diluted (10 fold) to 34.1 μg Cr/L 1.84 μg Sn/L
accuracy and precision	mean recovery 1:1 mixture of multi element standards XXI & XVII (QC): 1st measurement series: Cr: 96.7 ± 2.3 % (n = 11)  Sn: 97.1 ± 3.2 % (n = 11) 2nd measurement series: Cr: 96.3 ± 1.6 % (n = 11) Sn: 95.4 ± 1.8 % (n = 11)	Diluted to 5 μg Cr/L 5 μg Sn/L
accuracy and precision	mean recovery of multi element standards VIII: 7th measurement series: Cr: 97.6 ± 4.4 % (n = 4)	Diluted to 10 μg Cr/L
accuracy and precision	mean recovery 1:1 mixture of multi element standards XXI & XVII (QC): 3rd measurement series: Cr: 105.8 ± 2.0 % (n = 7) Sn: 100.8 ± 0.7 % (n = 7) 6th measurement series: Cr: 98.2 ± 0.5 % (n = 3)	Diluted to 10 μg Cr/L 10 μg Sn/L
	mean recovery quality control standard – 19 Elements: 4th measurement series: Cr: 102.4 ± 3.8 % (n = 7)	Diluted to 10 μg Cr/L Does not contain Sn
accuracy and precision	mean recovery for recalibration samples 1st measurement series: Cr: 98.3 ± 4.3 % (n = 11) Sn: 99.5 ± 4.1 % (n = 11) 2nd measurement series: Cr: 98.2 ± 1.2 % (n = 11) Sn: 97.9 ± 1.0 % (n = 11)	Diluted to 10 μg Cr/L 10 μg Sn/L
accuracy and precision; repeatability	mean recovery for recalibration samples 3rd measurement series: Cr: 106.5 ± 2.6 % (n = 7) Sn: 100.5 ± 0.6 % (n = 7) 4th measurement series: Cr: 103.2 ± 2.9 % (n = 7) Sn: 103.5 ± 2.9 % (n = 7) 5th measurement series: Cr: 109.1 ± 5.5 % (n = 6) Sn: 102.0 ± 4.3 % (n = 6) 6th measurement series: Cr: 90.8 ± 1.1 % (n = 3) 7th measurement series: Cr: 98.5 ± 0.9 % (n = 4)	Diluted to 5 μg Cr/L 5 μg Sn/L
trueness	recovery of fortified samples: ICP-MS Cr: 98.5 – 121.7 % (n = 21) Sn: 100.4 – 130.5 % (n = 21) ICP-OES Cr: 93.1 % and 96.7 % (n = 2)	A few samples (one sample for Cr and two samples for Sn) are not within the limits of 100 ± 15 %. However, this is noit critical because >60 % of all QA/QC samples are within these limits.

Conclusions:

The transformation/dissolution test (OECD Series on Testing and Assessment Number 29, 2001) of "Chrome tin orchid cassiterite " at a loading of 1 mg/L at pH 6 and 8, resulted after 28 days in maximum quantified Cr concentrations of 0.052 µg/L (pH = 8) and maximum Sn concentrations of 4.32 µg/L (pH = 8). The dissolved Cr and Sn concentrations were below 4.5 µg/L , referring to a solubility of < 0.45 wt%. Thus, the extent to which "Chrome tin orchid cassiterite " can produce soluble available ionic and other metal-bearing species in aqueous media is limited.

Description of key information

The solubility of chrome tin orchid cassiterite is < 0.45 wt% at a 1mg/L loading. . A GLP-conform transformation/dissolution test with a loading of 1 mg/L at pH6 and ph8 over 28 days, revealed higher dissolution at pH 8. Transformation/dissolution at a loading of 1 mg/L at pH8 after 7 days resulted in dissolved chromium and tin concentrations of 0.04µg/L, and 2.87 µg/L, respectively. The dissolved chromium and tin concentrations after 28 days were of 0.05 µg/L and 4.32 µg/L, respectively (Klawonn, 2017). The particle size of the tested sample (BET surface area 1.3 m2/g) is representative for the particle size on the market. Thus, the extent to which " chrome tin orchid cassiterite" can produce soluble available ionic and other metal-bearing species in aqueous media is limited.