Triazine derivative

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Testing was conducted between 27 March 2007 and 11 June 2007.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

Sponsor's identification: C-Y9
Description : yellow powder
Lot number : MB-1
Date received : 6 March 2007
Storage conditions: room temperature in the dark, over silica gel

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Details on sampling:

Preparation of samples
Sample solutions were prepared in stoppered glass flasks at a nominal concentration of 1 g/l in the three buffer solutions.
The test solutions were split into individual vessels for each data point.
The solutions were shielded from light whilst maintained at the test temperature.

Buffers:

Three buffer solutions were prepared at pH 4, 7 and 9.

Duration of test

Duration of test 1

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

1.01 g/L

Duration of test 2

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

1.01 g/L

Duration of test 3

Duration:

172 h

pH:

9

Initial conc. measured:

1.03 g/L

Results and discussion

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 2

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 3

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Any other information on results incl. tables

Results

Preliminary test

The mean peak areas relating to the standard and sample solutions are shown in the following table:

Solution	MeanArea
Standard 252 mg/l	5.895 x 10^3
Standard 253 mg/l	5.940 x 10^3
Initial Sample A, pH 4	5.934 x 10^3
Initial Sample B, pH 4	5.950 x 10^3
Standard 251 mg/l	5.892 x 10^3
Standard 251 mg/l	5.971 x 10^3
Initial Sample A, pH 7	5.962 x 10^3
Initial Sample B, pH 7	5.961 x 10^3
Standard 254 mg/l	5.908 x 10^3
Standard 253 mg/l	5.955 x 10^3
Initial Sample A, pH 9	6.042 x 10^3
Initial Sample B, pH 9	6.038 x 10^3
Standard 252 mg/l	5.944 x 10^3
Standard 251 mg/l	5.882 x 10^3
120 Hour Sample A, pH 4	5.835 x 10^3
120 Hour Sample B, pH 4	5.834 x 10^3
Standard 252 mg/l	5.971 x 10^3
Standard 251 mg/l	5.892 x 10^3
120 Hour Sample A, pH 7	5.792 x 10^3
120 Hour Sample B, pH 7	5.807 x 10^3
Standard 251 mg/l	5.926 x 10^3
Standard 251 mg/l	5.900 x 10^3
120 Hour Sample A, pH 9	5.131 x 10^3
120 Hour Sample B, pH 9	5.091 x 10^3
Standard 251 mg/l	5.678 x 10^3
Standard 253 mg/l	5.742 x 10^3
172 Hour Sample A, pH 9	5.909 x 10^3
172 Hour Sample B, pH 9	5.961 x 10^3

The test material concentrations at the given time points are shown in the following tables:

pH 4 at 50.0 ± 0.5ºC

	Time (Hours)
	0A	0B	120A	120B
Concentration (g/l)	1.01	1.01	0.992	0.992
% of initial	99.9	100.1	97.9	97.9

Result:             Less than 10% hydrolysis after 5 days at 50°C, equivalent to a half-life greater than 1 year at 25°C.

pH 7 at 50.0 ± 0.5ºC

	Time (Hours)
	0A	0B	120A	120B
Concentration (g/l)	1.01	1.01	0.981	0.983
% of initial	100	100	97.3	97.5

Result:             Less than 10% hydrolysis after 5 days at 50°C, equivalent to a half-life greater than 1 year at 25°C.

 pH 9 at 50.0 ± 0.5ºC

	Time (Hours)
	0A	0B	120A	120B	172A	172B
Concentration (g/l)	1.03	1.03	0.870	0.864	1.04	1.05
% of initial	100	100	84.4	83.8	101	102

Result:             Less than 10% hydrolysis after 172 hours at 50°C, equivalent to a half-life greater than 1 year at 25°C.

Validation

The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 0 to 504 mg/l. This was satisfactory with a correlation coefficient of 1.000 being obtained.

Discussion

At pH 9, a further timepoint at 172 hours indicated that the test material had not hydrolysed as first assumed from the 120 hour timepoint. It is deemed that the 120 hour sample result was erroneous.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The estimated half-life at 25°C of the test material for pH 4, pH 7 and pH 9 has been shown to be > 1 year.

Executive summary:

Abiotic Degradation, Hydrolysis as a Function of pH. 

Assessment of hydrolytic stability was carried out using Method C7 of Commission Directive 92/69/EEC and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The estimated half-life at 25ºC of the test material, for pH 4, pH 7 and pH 9 has been shown to be >1 year.