Disodium 1,3,4-thiadiazole-2,5-dithiolate

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

other: experimental study on parent compound

Adequacy of study:

supporting study

Study period:

2017-01-11 - 2018-02-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Version / remarks:

13-Apr-04

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
sponsor

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
At ambient temperature
- Stability under test conditions:
The test item is hydrolytically stable according to OECD 111 tier 1.

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

< 0

Temp.:

50 °C

Remarks on result:

not determinable

Conclusions:

The GLP study was performed according to OECD TG 117 without any deviations on the substance to be registered itself, the results were so obtained via a scientifically reasonable method. Hence, there is no doubt that the obtained results are not reliable: A determination of a partition coefficient (n-octanol/water) with the OECD 117 was not possible. Due to the fact that the test item has a retention before the dead time marker the OECD 117 is not valid to determine the log Pow of the test item.
The OECD 117 shows that the log Pow of the test item is < 0.0.

Executive summary:

The test item 2,5-Dimercapto-1,3,4-thiadiazole (“DMTD”) was tested according to OECD-Guideline 117 with the “HPLC-Method” under GLP. According to the definition of the OECD-Guideline 117 the test item shows a log Pow < 0.0. A more precise determination of the log Pow of the test item was not possible.

Reference 2

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Aug 2021 until 04 Nov 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

recent

Deviations:

not specified

GLP compliance:

not specified

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

-2.2

Temp.:

24 °C

pH:

> 7.53 - < 7.64

Remarks on result:

other: POW = 0.0066 ± 0.0001 (standard deviation)

Details on results:

The concentrations of the different test solutions were determined via the peak group of the test item (from 3.5 min to 11.0 min). The results are listed in the table below; each value represents the mean of a duplicate determination.
Test mixture Concentration of test item [mg/g], 1-octanol phase Concentration of test item
[mg/g], aqueous phase
1 0.012 1.770
2 0.012 1.805
3 0.012 1.785
4 0.012 1.845
5 < 0.012 1.805
6 0.012 1.815

The table below summarizes the calculated POW and log POW values, respectively.

Test mixture POW log POW Average POW Average log POW
1 0.0068 -2.169 0.0066 -2.177
2 0.0066 -2.177
3 0.0067 -2.172
4 0.0065 -2.187
5 < 0.0066 < -2.177
6 0.0066 -2.180
Total average over 6 independent determinations is indicated in the section above.

A pre test was conducted and its results indicated that the shake flask method is a suitable procedure for the determintaionof the test item´s partition coeficient. 

Pre-test – Shake flask:
24.1 mg of the test item were solved in 15 mL ammonium acetate puffer and 15 mL 1-Octanol added.
To determine the chromatographic conditions, this solution was analysed via ion chromatography.
Phase separation was achieved by centrifugation (20 min, 3500 rpm):
- organic phase was clear
- aqueous phase was clear, but slightly yellow
In both solutions the test item was observed via ion chromatography.

Conclusions:

Log Pow = -2.2

Executive summary:

The partition coefficient of the test item Disodium 1,3,4-thiadiazole-2,5-dithiolate was determined according to the OECD Guideline 107 (Shake Flask Method). Based on total average over 6 independent determinations, the following partion coefficient values of POW = 0.0066 ± 0.0001 (standard deviation), Log POW = -2.2 were obtained.
The pH value of the aqueous phases varied from 7.53 to 7.64. The Partition Coefficient was determined at 24.0 °C.

Description of key information

The substance partition coefficient was successfully determined in a shake flask method according to OECD Guideline 107 (test item, solid). Another study which was performed according to OECD Guideline 117 with the HPLC method, (test item in a miscibility fo, solution) failed to obtain a precise determination of a log Pow value. A log Pow of -2.2 was obtained from the key flask method study (at 24°C, pH 7.53-7.64).

Key value for chemical safety assessment

Log Kow (Log Pow):

-2.2

at the temperature of:

24 °C