2-chloro-N-[[[4-(trifluoromethoxy)phenyl]amino]carbonyl]benzamide

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

between November 1982 and December 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

no guideline available

Principles of method if other than guideline:

Triflumuron-chlorophenyl-ring-UL-14C was incubated in sterile buffer solutions (pH 5, 7 and 9, containing 1% acetonitrile) at a concentration of 0.05 ppm and s temperature of 25 °C. Triflumuron was stable at pH- 5 and 7

GLP compliance:

no

Radiolabelling:

yes

Analytical monitoring:

yes

Details on sampling:

Sample Analysis. At intervals of 0, 3, 7, 14 and 30 days, duplicate samples at each pH were radioassayed and analyzed by TLC. TLC was performed on silica gel 60 F-254 (Merck). Each sample was co-chromatographed with non-labeled standards.
The solvent systems employed were benzene/ethyl acetate/acetic acid (50:25:1) and hexane/ethyl acetate/acetic acid (25:25:1).
Radiocarbon zones on each plate were detected by autoradiography on Kodak XAR film. Non-radiolabeled standards were detected by flourescence quenching under ultra-violet light. The radioactive zones were isolated and radioassayed in a liquid scintillation spectrometer (Packard Instrument Co., Model No. 406).

Buffers:

The pH 5 and 7 buffers were prepared from distilled water using potassium biphidsphatem (KH2P04) and disodium phosphate (Na2HP04-7H20)2. The pH 9 buffer was prepared using boric acid (H3B03)-potassium chloride (KCl) and sodium hydroxide (NaOH)3. Final pH of the solutions were checked using an Orion Research, Model 201, pH meter.The pH of the buffers remained constant throughout the entire study at 5.2, 7.1 and 9.2, respectively.

Duration:

30 d

pH:

5

Temp.:

25 °C

Initial conc. measured:

0.05 other: ppm

Duration:

30 d

pH:

7

Temp.:

25 °C

Initial conc. measured:

0.05 other: ppm

Duration:

30 d

pH:

9

Temp.:

25 °C

Initial conc. measured:

0.05 other: ppm

Transformation products:

yes

No.:

#1

Details on hydrolysis and appearance of transformation product(s):

The major degradation product at pH 9 was 2-chlorobenzoic acid as determined by co-chromatography with an authentic standard in two TLC systems and by HPLC, The minor amount of 2-chlorobenzamide found in all buffer solutions was apparently a contaminant in the original Triflumuron standard.

Key result

pH:

7

Temp.:

25 °C

DT50:

465 d

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: slight degradation

Key result

pH:

9

Temp.:

25 °C

DT50:

57 d

Type:

(pseudo-)first order (= half-life)

Details on results:

The concentration after sonication for 30 minutes and ultracentrifugation for 2 hours appeared to plateau at 0.08 ppm. The pH of the buffers remained constant throughout the entire study at 5.2, 7.1 and 9.2, respectively.
Triflumuron was stable at pH 5 with no degradation detected throughout 30 days. Only slight degradation of the compound was detected after 30 days at pH 7 where an extrapolated half-life was calculated to be 465 days. For practical purposes, the compound could be considered stable at neutral pH conditions. Triflumuron in pH 9 buffered solutions exhibited a half-life of 57 days. Calculation of half-lives was based on first order kinetics using a straight line plot of log concentration versus time according to a least squares fit of the data. The major degradation product at pH 9 was 2-chlorobenzoic acid as determined by co-chromatography with an authentic standard in two TLC systems and by HPLC, The minor amount of 2-chlorobenzamide found in all buffer solutions was apparently a contaminant in the original Triflumuron standard.

Validity criteria fulfilled:

yes

Conclusions:

This study investigated the hydrolysis of chlorophenyl-labelled triflumuron in sterile buffer solutions (pH 5, 7 and 9; 0.05 ppm; 25 °C) over a 30-day period. Triflumuron was stable at pH 5 and 7; the half-life at pH 9 was 57 days. No volatile degradation products were found. The primary degradation product was 2-chlorobenzoic acid (CBA).

Executive summary:

Triflumuron-chlorophenyl-ring-UL-14C was incubated in sterile buffer solutions (pH 5, 7 and 9, containing 1% acetonitrile) at a concentration of 0.05 ppm and s temperature of 25°C. Triflumuron was stable at pH- 5 and 7. the half-life at pH 9 was 57 days. No volatile degradation products were found. The primary degradation product in solution was 2-chlbrobenzoic acid.

Description of key information

This study investigated the hydrolysis of chlorophenyl-labelled triflumuron in sterile buffer solutions (pH 5, 7 and 9; 0.05 ppm; 25 °C) over a 30-day period. Triflumuron was stable at pH 5 and 7; the half-life was estimated to be 465 days at pH 7 and at pH 9 was 57 days. No volatile degradation products were found. The primary degradation product was 2-chlorobenzoic acid (CBA).

Key value for chemical safety assessment

Half-life for hydrolysis:

465 d

at the temperature of:

25 °C