Tetrakis(diethyldithiocarbamato-S,S')tellurium

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Jun 2017 to 14 Feb 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

validation criteria were nto met due to chelation or metal exchange of the test item

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

July 1995

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Specific details on test material used for the study:

- Name of test material (as cited in study report): (tetrakis(diethyldithiocarbamato-S,S')tellurium
- Batch No: 60700109
- Purity: 99.0%
- Date of reception in the test facility: 27 February 2017
- Expiration date of the test item: 14 July 2018
- Appearance: yellow powder
- Storage conditions: well-ventilated place, ambient temperature and obscurity

Key result

Water solubility:

0.634 mg/L

Conc. based on:

test mat.

Incubation duration:

>= 1.7 - <= 24.6 h

Temp.:

20.5 °C

pH:

>= 4.7 - <= 5.3

Details on results:

The water solubility of the test item was calculated as the mean of the concentrations determined at both 12.5 mL/h flow rates. The value obtained was 0.634 mg/L. The temperature in column #1 test ranged from 20.3 - 22.4 C° (mean: 20.5 °C). The temperature in column #2 test ranged from 20.4 - 20.5 C° (mean: 20.5 °C). All samples were between pH 4.7 and 5.3.

The repeatability of the analysis has shown high variability as many % Relative Standard Deviation (RSD) are far from the maximum acceptable tolerance (i.e. 20%). It is well-known that dithiocarbamates exhibit a high propensity to chelate or exchange metal ions (i.e. Tellurium in the case of the test item), from the medium, containers, or other analytical equipment’s. This is probably causing the lack of robustness of the method (random signal response over time). Therefore, the data obtained should be taken with caution.
Although the test item concentrations as determined during this study are not fully reliable the following conclusions are proposed:
- Concentration/time curves: Except the results obtained at 25 mL/h flow rate and despite some outliers values these curves show that a saturation plateau was reached by the second sample at all tested flow rates: the test item solubility seems to be between 0.3 and 0.9 mg/L.
- Column test #1: The solubility measured was clearly higher with the lower flow rate and thus the data obtained with the higher flow rate should be disregarded: the test item concentrations determined at the 25 mL/h flow rate are not used for the final calculations.
- Column test #2 at flow rate 6 mL/h: All % RSD are clearly higher the maximum acceptable tolerance and thus are also disregarded: the test item concentrations determined during both tests carried at 12.5 ml/h are thus used for the final calculations.
- Column test#1 & test #2 at 12.5 mL/h: The test item concentrations for which % RSD is >20% are disregarded.

The test item solubility was thus calculated from determinations of the "retained samples", shown in the first table in 'Any other information on results incl. tables'. The results from all tests are provided in this section as well.

Table: Test item measurements of the two column tests

Test	Sample ''retained'’	Time (hours)	Test item concentration (mg/L)				Standard Deviation	RSD (%)
			Measure 1	Measure 2	Measure 3	Mean
Column test #1	#3	1.7	0.655	0.71	0.726	0.697	0.037	5.3
	#4	2.8	0.716	0.845	0.822	0.794	0.069	8.7
	#5	3.8	0.896	0.868	0.833	0.866	0.031	3.6
	#6	4.8	0.994	0.859	0.932	0.928	0.068	7.3
	#8	21.9	0.718	0.61	0.608	0.646	0.063	9.8
	#9	22.9	0.605	0.583	0.586	0.592	0.012	2.1
	Column test #1 results					0.754	0.131	17.4
Column test #2	#4	20.6	0.45	0.399	0.558	0.469	0.081	17.2
	#5	22.6	0.347	0.334	0.371	0.351	0.019	5.3
	#6	24.6	0.371	0.352	0.375	0.366	0.012	3.3
	Column test #2 results					0.395	0.064	16.2
	Colum test #1 & #2 results					0.634	0.209	33

RSD: Relative standard deviation

Table: Test Item Determinations (Column Test #1, Flow Rate 25 mL/h)

Sample	Time (hours)	Test item concentration (mg/L)				Standard Deviation	RSD (%)
		Measure 1	Measure 2	Measure 3	Mean
#1	T0	<QL	<QL	<QL	<QL	NA	NA
#2	0.9	0.129	0.135	0.153	0.139	0.012	8.9
#3	1.8	0.139	0.147	0.157	0.147	0.009	6.1
#4	2.9	0.151	0.183	0.173	0.169	0.016	9.8
#5	3.9	0.181	0.166	0.169	0.172	0.008	4.6
#6	4.9	0.173	0.157	0.158	0.163	0.009	5.8
#7	5.9	0.059	0.038	0.029	0.042	0.015	37
#8	22	0.131	0.107	0.108	0.115	0.013	11.7
#9	23	0.102	0.099	0.097	0.099	0.003	2.7
#10	24	0.157	0.157	0.154	0.156	0.001	0.9
#11	25	0.182	0.185	0.176	0.181	0.005	2.5

< DL (4.01 μg/L): concentration lower than the Detection Limit

< QL (13.4 μg/L): concentration lower than the Quantification Limit

NA: Not Applicable

RSD: Relative Standard Deviation

 

Table: Test Item Determinations (Column Test #1, Flow Rate 12.5 mL/h)

Sample	Time (hours)	Test item concentration (mg/L)				Standard Deviation	RSD (%)
		Measure 1	Measure 2	Measure 3	Mean
#1	T0	<QL	<QL	<QL	<QL	NA	NA
#2	0.8	0.141	0.15	0.163	0.151	0.011	7.2
#3	1.7	0.655	0.71	0.726	0.697	0.037	5.3
#4	2.8	0.716	0.845	0.822	0.794	0.069	8.7
#5	3.8	0.896	0.868	0.833	0.866	0.031	3.6
#6	4.8	0.994	0.859	0.932	0.928	0.068	7.3
#7	5.8	0.833	0.717	0.397	0.649	0.226	34.8
#8	21.9	0.718	0.61	0.608	0.646	0.063	9.8
#9	22.9	0.605	0.583	0.586	0.592	0.012	2.1

< DL (4.01 μg/L): concentration lower than the Detection Limit

< QL (13.4 μg/L): concentration lower than the Quantification Limit

NA: Not Applicable

RSD: Relative Standard Deviation

 

Table: Test Item Determinations (Column Test #2, Flow Rate 12.5 mL/h)

Sample	Time (hours)	Test item concentration (mg/L)				Standard Deviation	RSD (%)
		Measure 1	Measure 2	Measure 3	Mean
#1	T0	0.013	0.014	0.014	0.014	0	1.9
#2	16.6	0.613	0.435	0.373	0.473	0.125	26.4
#3	18.6	0.364	0.257	0.259	0.293	0.061	20.9
#4	20.6	0.45	0.399	0.558	0.469	0.081	17.2
#5	22.6	0.347	0.334	0.371	0.351	0.019	5.3
#6	24.6	0.371	0.352	0.375	0.366	0.012	3.3
#7	40.6	0.334	0.237	0.2	0.257	0.069	27
#8	42.6	0.815	0.596	0.499	0.636	0.162	25.4
#9	44.8	0.86	0.421	0.31	0.53	0.291	54.9
#10	46.6	0.785	0.496	0.41	0.563	0.197	34.9
#11	48	0.735	0.373	0.319	0.476	0.226	47.6

< DL (4.01 μg/L): concentration lower than the Detection Limit

< QL (13.4 μg/L): concentration lower than the Quantification Limit

RSD: Relative Standard Deviation

 

Table: Test Item Determinations (Column Test #2, Flow Rate 6 mL/h)

Sample	Time (hours)	Test item concentration (mg/L)				Standard Deviation	RSD (%)
		Measure 1	Measure 2	Measure 3	Mean
#1	T0	0.041	0.048	0.048	0.045	0.004	9
#2	16.1	0.871	0.506	0.423	0.6	0.238	39.7
#3	20.1	0.495	0.48	0.862	0.612	0.216	35.3
#4	24.1	0.454	0.314	0.295	0.354	0.087	24.5
#5	40.1	0.447	0.248	0.205	0.3	0.129	43.1
#6	44.3	2.555	1.289	0.916	1.586	0.859	54.2
#7	47.5	0.925	0.413	0.319	0.552	0.326	59.1

< DL (4.01 μg/L): concentration lower than the Detection Limit

< QL (13.4 μg/L): concentration lower than the Quantification Limit

RSD: Relative Standard Deviation

VALIDATION CRITERIA

The following guidelines recommendations were not met:

- It was technically not possible to get reliable data from 2 successive runs carried at 2 different flow rates. The test results were thus calculated from 2 runs at the same flow rate of 12.5 mL/h.

- Due to unreliable measurements it was not possible to get at least five consecutive samples taken from the saturation plateau

- The mean values obtained from two tests with identical flows differed by more than 30%

Description of key information

The water solubility of the test item was determined to be 0.634 mg/L at 20.5 °C (mean) and pH 4.7 - 5.3

Key value for chemical safety assessment

Water solubility:

0.634 mg/L

at the temperature of:

20 °C