1,2,4-triazole-3-thiol

Partition coefficient

Administrative data

Endpoint:

partition coefficient

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

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

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

-0.398

Temp.:

21 °C

pH:

5

Any other information on results incl. tables

1.1     Overview of Determinations

The P_OWfor each determination, the mean, standard deviation and relative standard deviation of the six determinations are presented in the following table.

Table 10.1‑a    P_OW

Step	POW	Mean POWStep	Mean POW	Standard Deviation	Relative Standard Deviation
1a	0.39	0.39	0.40	0.012	3.0%
1b	0.39
2a	0.41	0.40
2b	0.40
3a	0.42	0.41
3b	0.40

 

The log P_OWfor each determination, the mean, standard deviation and relative standard deviation of the six determinations is presented in the following table.

Table 10.1‑b    log P_OW

Step	log POW	Mean Log POW Step	Mean log POW	Range	Standard Deviation	Relative Standard Deviation
1a	-0.410	-0.412	-0.398	0.025	0.013	3.3%
1b	-0.414
2a	-0.391	-0.395
2b	-0.398
3a	-0.380	-0.387
3b	-0.393

 

1.2     log P_OW

The log P_OWof the test item3-Mercapto-1,2,4-triazolewas calculated as (log P_OW± standard deviation):

 

-0.398 ± 0.013

1.3     Validity

The six log P_OWs should lie in a range of ± 0.3 units.

The range was 0.025, corresponding to range ± 0.013

 

1.4     Mass Balance

The mass balances of the individual determinations are presented in the following table.

Table10.4‑aMass Balances

Step	Amount in n-Octanol [mg]	Amount inBuffer pH 5 [mg]	Total Amount [mg]	Nominal Amount [mg]	Difference [mg]	Difference	Recovery
1a	3.02	15.542	18.57	18.00	0.57	3.1%	103.1%
1b	2.98	15.433	18.41	18.00	0.41	2.3%	102.3%
2a	1.71	16.827	18.54	18.00	0.54	3.0%	103.0%
2b	1.66	16.662	18.33	18.00	0.33	1.8%	101.8%
3a	5.44	13.056	18.49	18.00	0.49	2.7%	102.7%
3b	5.39	13.321	18.71	18.00	0.71	4.0%	104.0%

Applicant's summary and conclusion

Conclusions:

The analytical method showed good correlation coefficients and the measured concentrations lie in the working ranges. Therefore, the determination of the concentration of 3-Mercapto-1,2,4-triazole in n-octanol and buffer pH 5 can be considered valid.
The mass balance shows discrepancies below 5% at all three steps. These differences might be due to the measurement uncertainties of analytical instruments and of sample preparation.
The range of the determined log POWs was 0.025, corresponding to range of ± 0.013. Therefore, the determination was valid.
The determination of log POW using the shake flask method is possible in the range of -2 and 4. The log POW of the test item 3-Mercapto-1,2,4-triazole was stated as
-0.398 ± 0.013 (log POW ± standard deviation).

Executive summary:

The study was performed using the flask method. Partition coefficient was determined using n-octanol, saturated with Buffer pH 5 and buffer pH 5, saturated with n-octanol.

Three volume ratios of buffer pH 5 / n-octanol (saturated phases) (ratios 4 : 1, 2 : 1 and 1 : 1) were tested in duplicate.

The separated phases were analysed using HPLC as described in chapter 6.4.

The measurements of the phases gave the following log P_OWof the test item at the respective ratio:

Table3-a        Results

Ratio^1	Step log POW	Mean log POW	Standard Deviation	Relative Standard Deviation
4 : 1	-0.395	-0.398	0.013	3.3%
2 : 1	-0.412
1 : 1	-0.387

¹Ratio of buffer pH 5 / n-octanol (saturated phases)

The test was performed at 21°C.