1,2,4-triazole-3-thiol

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

1,2,4-triazole-3-thiol

EC Number:

221-656-6

EC Name:

1,2,4-triazole-3-thiol

Cas Number:

3179-31-5

Molecular formula:

C2H3N3S

IUPAC Name:

4H-1,2,4-triazole-3-thiol

Test material form:

solid: crystalline

Results and discussion

Water solubility

Key result

Water solubility:

89.76 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

500 g/L

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

5

Any other information on results incl. tables

The measurements of the day 1-3 were included in the calculation of the mean.

Table8.3‑a       Measurements used for Calculation of Solubility

Day	Flask	Concentration [g/L]	Total Mean [g/L]	Total Standard Deviation [g/L] (RSD* [%])
1	1 A	89.51	89.76	1.44 (1.6)
2	1 B	89.14
3	1 C	88.11
3	2	89.18
3	3	89.25
3	4	89.18
3	5	92.73
3	6	91.01

*RSD = relative standard deviation

 

Mean at the plateau is 89.76 g/L. A standard deviation of 1.44 g/L was calculated, giving a relative standard deviation of 1.6 %.

Temperature was measured with 20.1 - 20.5 °C.

Applicant's summary and conclusion

Conclusions:

The solubility of 3-Mercapto-1,2,4-triazole in water was determined from the measured concentrations in the filtrated test solutions with 89.76 g/L.
All replicates showed good correspondence. Standard deviation of the samples, which were used for the calculation of water solubility, was 1.44 g/L, corresponding to a relative standard deviation of 1.6 %.
Equilibration was considered to be reached after 1 day, as no further increase in solubility was noticed after 1 day. Therefore, all flasks were taken into account for the final calculation of the solubility.

All replicates showed very good correspondence. Standard deviation of the test item concentration in all measured flasks was very low.
No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Executive summary:

The solubility of the test item3-Mercapto-1,2,4-triazolein water was determined by measurement of the test item concentration in the filtrated test solutions using HPLC.

In the pre-tests no complete dissolution was achieved for test item / water-mixtures with nominal concentration 10 g/L. Therefore, flasks with nominal concentrations 50 g/L and
10 g/L were treated 30 minutes in ultrasonic bath and shaken at room temperature for one day. Then, the test item concentration was measured after membrane filtration (0.45 µm, PTFE) to test for concentration dependency Undissolved particles were observed in both flasks. Dependency of solubility on amount of the test item (nominal load) was assumed. According to the guideline, the flask method was used for the determination of the solubility of the test item in water.

In the main test,six different loading rates of the test item were chosen to study the effect of the loading rate on the measured water solubility: 100, 200, 400, 500, 600, and 800 g/L (nominal). Three flasks 1A - C with the same loading rate (500 g/L) were used during equilibration. Seven vessels (flasks blank, 1C (for the sampling point 72 h) and 2 – 6) were set onto the shaking apparatus immediately. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature (20.0 ± 0.5 °C). Then, flasks 1A - 1C were taken from the shaker, samples were taken, membrane filtered and analysed via HPLC.

No rising tendency in concentration of the solutions was found on day 3. No differences above 15% in the concentration of the solutions could be determined between the sampling dates 2 and 3, supporting the hypothesis, that the maximum concentration of the test item had been reached. Therefore, the flasks 2 - 6 were sampled, filtrated and analysed.

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicatingthat no colloidal dispersed particles or micells are present.

Dependency of solubility on amount of the test item (nominal load) was not perceived in the main study. A low relative standard deviation of 1.6 % was obtained for the measured concentrations in all flasks.

At the plateau, the concentration of3-Mercapto-1,2,4-triazolein water had reached

89.76 ± 1.44 g/L at 20.1 – 20.5 °C

= 89.76 ± 1.44 kg/m³(SI units)

(mean value ± standard deviation of eight individual vessels)