Pyrochlore, antimony lead yellow

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:

2009-11-04 to 2010-04-14

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

(a) the 28-day test with a loading of 1 mg/L was conducted at pH 6 instead of 5.5. (b) `mass balance (%) after completion of the transformation test´ is missing. (c) the within- and between-vessel variation was not always below the demanded limit (<10 % and <20 % respectively).

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:

yes

Remarks:

please refer to the field "Rationale for reliability incl. deficiencies" above

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2009-06-19

Type of method:

flask method

Remarks:

transformation/dissolution

Type of test:

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

Mean dissolved conc.:

2 µg/L

Element analysed:

Sb

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH: 5.87 - 5.89, Temp.: 22.5 °C

Remarks on result:

other: SD: +/- 0.04 µg/L

Type of test:

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

Mean dissolved conc.:

121 µg/L

Element analysed:

Pb

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH: 5.87 - 5.89, Temp.: 22.5 °C

Remarks on result:

other: SD: +/- 39 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

2 µg/L

Element analysed:

Sb

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH: 5.88 - 5.92, Temp.: 22.6 °C

Remarks on result:

other: SD: +/- 0.5 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

112 µg/L

Element analysed:

Pb

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH: 5.88 - 5.92, Temp: 22.6 °C

Remarks on result:

other: SD: +/- 36 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

2 µg/L

Element analysed:

Sb

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 5.82 - 5.93, Temp: 23.4 °C

Remarks on result:

other: SD: +/- 0.5 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

105 µg/L

Element analysed:

Pb

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH: 5.82 - 5.93, Temp.: 23.4 °C

Remarks on result:

other: SD: +/- 34 µg/L

Type of test:

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

Mean dissolved conc.:

4 µg/L

Element analysed:

Sb

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH: 6.01 - 6.04, Temp: 22.5 °C

Remarks on result:

other: SD: +/- 0.1 µg/L

Type of test:

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

Mean dissolved conc.:

325 µg/L

Element analysed:

Pb

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH: 6.01 - 6.04, Temp.: 22.5 °C

Remarks on result:

other: SD: +/- 54 µg/L

Type of test:

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

Mean dissolved conc.:

26 µg/L

Element analysed:

Sb

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH 6.04 - 6.06, Temp.: 22.5 °C

Remarks on result:

other: SD: +/- 2 µg/L

Type of test:

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

Mean dissolved conc.:

2 936 µg/L

Element analysed:

Pb

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH: 6.04 - 6.06, Temp.: 22.5 °C

Remarks on result:

other: SD: +/- 341 µg/L

Details on results:

The analytical method was shown to be specific for content determination of lead and antimony in aqueous samples.
The range tested from 0.1 to 50.0 ng/mL was found to be linear for Sb and Pb (correlation coefficient > 0.99 for both metals).
The limit of quantification (L.O.Q.) of the method was 1 ng/mL for Sb and Pb, defined as the lowest fortification level.
The instrumental limit of detection (M.D.L.) defined as the lowest calibration level, was 0.1 ng/mL for Sb and Pb.
The limit of detection (L.O.D.) of the method, defined as 50% of the lowest fortification level, was 0.5 ng/mL for both metals.
Metals results calculated as values lower than L.O.D. are classified as not detected (n.d.).
Metals results calculated as greater than the limit of detection but less than limit of quantification, were designated as < 1 ng/mL for Sb and Pb.
If the metals results are greater than 10 ng/mL, the solution must be suitably diluted in volumetric flasks.
The test was performed spiking each test media three times with known amounts of Sb and Pb at two fortification levels (1 ppb for the low level and 10 ppb for the high level). Each spiked test media was shaken for 24 hours and then sampling and analyzing accordingly the procedure described above.
Considering the low concentration tested (low fortification level 1 ppb and high fortification level 10 ppb) the accuracy of the analytical method can be considered acceptable.
No matrix effect was observed and no contribution of the filter procedure was observed.

Screening Test at 1g/L		^121Sb (µg/L)	^208Pb (µg/L)
2900094-001 pH 6 T24h	Mean	20	3202
	S.D.	1	302
	RSD (%)	6 %	9 %
2900094-001 pH 8 T24h	Mean	23.	2095
	S.D.	0.2	254
	RSD (%)	1 %	12 %

Conclusion of the screening test:

The dissolution was higher at pH 6 than at pH 8. Therefore, the full test was conducted at pH 6 to maximise transformation/dissolution.

Full Test 7 days at pH6 at 100 mg/L		^121Sb (µg/L)	^208Pb (µg/L)
2900094-001 T2 hours	Mean	23	3652
	S.D.	-	-
	RSD (%)	-	-
2900094-001 T6 hours	Mean	22	3494
	S.D.	-	-
	RSD (%)	-	-
2900094-001 T1 day	Mean	25	3773
	S.D.	6	54
	RSD (%)	26 %	14 %
2900094-001 T2 days	Mean	25	3692
	S.D.	5	484
	RSD (%)	20 %	13 %
2900094-001 T6 days	Mean	26	3454
	S.D.	3	401
	RSD (%)	12 %	12 %
2900094-001 T7 days	Mean	26	2936
	S.D.	2	341
	RSD (%)	7 %	12 %

Full Test 7 days at pH6 at 10 mg/L		^121Sb (µg/L)	^208Pb (µg/L)
2900094-001 T2 hours	Mean	3	438
	S.D.	-	-
	RSD (%)	-	-
2900094-001 T6 hours	Mean	3	415
	S.D.	-	-
	RSD (%)	-	-
2900094-001 T1 day	Mean	5	491
	S.D.	1	69
	RSD (%)	16	14 %
2900094-001 T2 days	Mean	5	418
	S.D.	1	55
	RSD (%)	15 %	135 %
2900094-001 T6 days	Mean	4	394
	S.D.	0.40	41
	RSD (%)	9 %	10 %
2900094-001 T7 days	Mean	4	325
	S.D.	0.1	54
	RSD (%)	3 %	17 %

Full Test 28 days at pH6 at 1 mg/L		^121Sb (µg/L)	^208Pb (µg/L)
2900094-001 T2 hours	Mean	n.d.	55
	S.D.	-	-
	RSD (%)	-	-
2900094-001 T6 hours	Mean	n.d.	67
	S.D.	-	-
	RSD (%)	-	-
2900094-001 T1 day	Mean	2	121
	S.D.	0.04	39
	RSD (%)	2 %	32 %
2900094-001 T2 days	Mean	2	120
	S.D.	0.5	39
	RSD (%)	31 %	33 %
2900094-001 T6 days	Mean	2	122
	S.D.	0,5	39
	RSD (%)	29 %	31 %
2900094-001 T7 days	Mean	2	112
	S.D.	0.5	36
	RSD (%)	30 %	32 %
2900094-001 T14 days	Mean	2	111
	S.D.	0.5	36
	RSD (%)	31 %	33 %
2900094-001 T21 days	Mean	2	108
	S.D.	0.5	36
	RSD (%)	31 %	33 %
2900094-001 T28 days	Mean	2	105
	S.D.	0.5	34
	RSD (%)	30 %	33 %

Test conditions:

-The pH was out of the acceptable range (pH6 +0.2 units) in a range of 5.72 to 6.08

- The temperature was inside of the acceptable range (20 -25 +/- 2) in a range of 22.4 to 24.6

- The O2 -concentration was always above the accaptable limit of 70 % in a range of 80.3 % to 88.9 %

- The within-vessel value from the 100 mg/L loading of Sb at the 7 days endpoint is in a range of 2 to 10 % (i.e. ≤10 %) and the between-vessel value is 7 % (i.e. ≤20 %).

- The within-vessel value from the 100 mg/L loading of Pb at the 7 days endpoint is in a range of 2 to 6 % (i.e. ≤10 %) and the between- vessel value is 12 % (i.e. ≤20 %).

- The within-vessel value from the 10mg/L loading of Sb at the 7 days endpoint is in a range of 3 to 27 % (i.e. >10 %- not guideline confirm) and the between-vessel value is 3 % (i.e. ≤20 %). The within-vessel value is higher than 10 % but taking into account the precision of the analytical method estimated at 10 % and the antimony low dissolved concentration values determined, can be considered acceptable.

- The within-vessel value from the 10 mg/L loading of Pb at the 7 days endpoint is in a range of 0 to 3 % (i.e. ≤10 %) and the between-vessel value is 17 % (i.e. ≤20 %).

- The within-vessel value from the 1 mg/L loading of Sb at the 7 days endpoint is in a range of 1 to 4 % (i.e. ≤10 %) and the between-vessel value is 30 % (i.e. >20 %). The between-vessel value is higher than 20 % but taking into account the precision of the analytical method estimated at 10 % and the antimony low dissolved concentration values determined, can be considered acceptable.

- The within-vessel value from the 1 mg/L loading of Sb at the 28 days endpoint is in a range of 1 to 5 % (i.e. ≤10 %) and the between-vessel value is 30 % (i.e. >20 %). The between-vessel value is higher than 20 % but taking into account the precision of the analytical method estimated at 10 % and the antimony low dissolved concentration values determined, can be considered acceptable.

- The within-vessel value from the 1 mg/L loading of Pb at the 7 days endpoint is in a range of 2 to 4 % (i.e. ≤10 %) and the between-vessel value is 32 % (i.e. >20 %). The between-vessel value is higher than 20 % but taking into account the precision of the analytical method estimated at 10 % and the low dissolved concentration values determined, can be considered acceptable.

- The within-vessel value from the 1 mg/L loading of Pb at the 28 days endpoint is in a range of 2 to 4 % (i.e. ≤10 %) and the between-vessel value is 32 % (i.e. >20 %). The between-vessel value is higher than 20 % but taking into account the precision of the analytical method estimated at 10 % and the low dissolved concentration values determined, can be considered acceptable.

Conclusions:

The test item PYROCHLORE ANTIMONY LEAD YELLOW has a loading dependent dissolution of Sb and Pb in aqueous media at pH 6. A direct time dependence was not observed.

- after 7 days, loading of 1 mg/L: 2 +/- 0.5 µg Sb/L, 112 +/- 36 µg Pb/L
- after 7 days, loading of 10 mg/L: 4 +/- 0.1 µg Sb/L, 325 +/- 54 µg Pb/L
- after 7 days, loading of 100 mg/L: 26 +/- 2 µg Sb/L, 2936 +/- 341 µg Pb/L
- after 28 days, loading of 1mg/L: 2 +/- 0.5 µg Sb/L, 105 +/- 34 µg Pb/L

Description of key information

The test item pyrochlore has a loading dependent dissolution of Sb and Pb in aqueous media at pH 6. 26 µg/L Sb and 2936.3 µg/L Pb are dissolved at 22.5 °C (7 days observation) at the higest loading of 100mg/L.

Additional information

The test item PYROCHLORE ANTIMONY LEAD YELLOW has a loading dependent dissolution of Sb and Pb in aqueous media at pH 6. A direct time dependence was not observed.

- after 7 days, loading of 1 mg/L: 2 +/- 0.5 µg Sb/L, 112 +/- 36 µg Pb/L

- after 7 days, loading of 10 mg/L: 4 +/- 0.1 µg Sb/L, 325 +/- 54 µg Pb/L

- after 7 days, loading of 100 mg/L: 26 +/- 2 µg Sb/L, 2936 +/- 341 µg Pb/L

- after 28 days, loading of 1mg/L: 2 +/- 0.5 µg Sb/L, 105 +/- 34 µg Pb/L