2H-Tetrazol-5-amine, potassium salt (1:1)

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:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Test material

Test material information

Constituent 1

Reference substance name:

potassium 5-amino-1H-1,2,3,4-tetrazol-1-ide

Cas Number:

136369-04-5

Molecular formula:

CH2KN5

IUPAC Name:

potassium 5-amino-1H-1,2,3,4-tetrazol-1-ide

Test material form:

solid: particulate/powder

Details on test material:

Batch no.: 08KI030

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

-0.129

Temp.:

22 °C

pH:

6.89

Applicant's summary and conclusion

Conclusions:

Variations in the retention times of reference items and test item are very small. Therefore a stable configuration of the HPLC-column can be assumed. The correlation log K/log POW is good. The coefficient of determination r2 was calculated with 0.9797. This value was considered as sufficiently high to use the calibration function for the determination of the log POW of the test item 5-Aminotetrazol Potassium. The test item gave a peak close to the dead time, which was expected taking into account the ionic nature of the substance. The reference item with the lowest log POW which is stated in the guideline (2-butanone, log POW 0.3) had a higher retention time. Therefore, log POW of 5-Aminotetrazol Potassium is stated as < 0.3. Correlation within the three injections was very good though. Therefore, no impact on the outcome of the determination is expected if the study were repeated using the shake-flask method. The shake-flask method covers the range of – 2 < log POW < 4, but as no valid analytical method for the determination in octanol is available, larger uncertainty in log POW value is expected if this method were used. The result of the study is considered valid.

Executive summary:

The study was performed using a HPLC with a C18 column. Six reference items with different retention times were used to produce a calibration curve, since retention time on hydrophobic columns and POW are correlated. The reference items were chosen on behalf of the retention time of the test item on the column. First, a solution of the reference items was analysed with HPLC, then a solution of the test item, and finally again the solution with the reference items. Each analysis was performed three times, totalling to nine runs.

For each reference item, the capacity factor K was calculated from the retention time of thio urea and the retention time of the respective reference item. A calibration function (log K versus log POW, linear fit) was determined using the literature values for POW of the reference items and the retention times in the six determinations. The chromatogram of the test item gave one peak. With the help of the calibration function log K versus log POW, the corresponding log POW was determined as:

Peak	Mean retention time [min]	Log POW +- sd
1	1.366	-0.129 +-0.022