Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
15 February 2002 - 11 April 2002
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: guideline study under GLP compliance with no restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OPPTS 835.2110 (Hydrolysis as a Function of pH)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 2-(N-methylperfluorobutanesulfonamido)ethyl acrylate (N-MeFBSEA)
- Substance type: single-constituent substance
- Storage condition of test material: Frozen
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
- Sampling intervals for the parent/transformation products: Test bottles with concentration of 4 ppm N-MeFBSEA in buffers of pH 4, 7 and 9 were sampled at 0, and 5 days;
- Sample storage conditions before analysis: 50 °C;
Buffers:
pH: 4,7,9
Details on test conditions:
TEST SYSTEM

-Type, material and volume of test flasks, other equipment used: VOA vials
- Measures to exclude oxygen: Buffers of pH 4, 7, and 9 were sparged with Argon for at least ten minutes prior to transfer into Argon sparged vials.

TEST MEDIUM
- Identity and concentration of co-solvent: no co-solvent

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Dissolved oxygen: purged with Argon
Tetrahydrofuran (THF) will be added post hydrolysis as a dilution solvent
Duration of test
Duration:
5 d
Temp.:
50 °C
Initial conc. measured:
4 mg/L
Number of replicates:
3
Positive controls:
no
Negative controls:
no
Statistical methods:
None

Results and discussion

Transformation products:
yes
Identity of transformation products
No.:
#1
Reference
Reference substance name:
Unnamed
IUPAC name:
2-(N-methylperfluorobutanesulfonamido) ethyl alcohol (N-MeFBSE Alcohol);
Identifier:
common name
Identity:
2-(N-methylperfluorobutanesulfonamido) ethyl alcohol (N-MeFBSE Alcohol);
Details on hydrolysis and appearance of transformation product(s):
2-(N-methylperfluorobutanesulfonamido) ethyl acrylate (N-MeFBSEA) is expected to hydrolyze to form 2-(N-methylperfluorobutanesulfonamido) ethyl alcohol (N-MeFBSE Alcohol). Additional hydrolysis products are 2-N-methylperfluorobutanesulfonamide (N-MeFBSA), perfluorobutanesulfonate (PFBS) and perfluorobutanesulfonamide (FBSA). See Fig 1
Dissipation DT50 of parent compoundopen allclose all
pH:
7
Temp.:
25 °C
DT50:
0.605 yr
Type:
(pseudo-)first order (= half-life)
Remarks on result:
other: extrapolation from half-life at 50 °C
pH:
7
Temp.:
50 °C
Hydrolysis rate constant:
0.031 d-1
DT50:
22.078 d
Type:
(pseudo-)first order (= half-life)
Remarks on result:
other: Remarks: T1/2 = (ln2) /k;
Details on results:
- Formation and decline of each transformation product during test: four possible hydrolysis product were monitored:
2-(N-methylperfluorobutanesulfonamido) ethyl alcohol (N-MeFBSE Alcohol); 2-N-methylperfluorobutanesulfonamide (N-MeFBSA);
perfluorobutanesulfonate (PFBS);
perfluorobutanesulfonamide (FBSA).

Appearance of N-MeFBSE Alcohol as a degradation product was found in all pH buffers, with the hydrolysis most rapid at pH 7 and only slightly slower at pH 9. At pH 4, the appearance of N-MeFBSE Alcohol as a degradation product was much slower. In pH 9 buffer, two additional hydrolysis products (FBSA and MeFBSA) were found at day 0, however, the concentration decreased to the level of quantitation limits at day 5. No PFBS was found in all buffers.

Typically, hydrolysis is considered to be either acid or base catalyzed and it would appear that the exact opposite of this was observed for N-MeFBSEA. However, this is a two point kinetic analysis where very small changes in observed concentrations resulted in large changes in determined half-lives.

The hydrolytic degradation of N-MeFBSEA studied was conducted at 50°C over 5 days. Half-lives were extrapolated to 25 °C by multiplying by a factor of 10. This is valid for reactions such as these (ester hydrolysis), which have an Arrhenius heat of activation (AH,) of approximately 18 Kcal/mole.

Any other information on results incl. tables

Table 1: Summary of hydrolysis for C4 Acrylate

 

 

Compound

pH = 4

Day 0

Day 5

Change

T1/2 (year)(1)

FBSA

ND

ND

UND

UND

PFBS

ND

ND

UND

UND

MeFBSA

ND

ND

UND

UND

N-MeFBSE Alcohol(3)

0.0271

0.0520

0.0249

15.14

 

Compound

pH = 7

Day 0

Day 5

Change

T1/2 (year)(1)

FBSA

ND

ND

UND

UND

PFBS

ND

ND

UND

UND

MeFBSA

ND

ND

UND

UND

N-MeFBSE Alcohol(3)

0.0172

0.5974

0.5802

0.6049

 

Compound

pH = 9

Day 0

Day 5

Change

T1/2 (year)(1)

FBSA

0.3669

0.01810(2)

0.3488

0.03153

PFBS

ND

ND

UND

UND

MeFBSA

0.3044

0.01870(2)

0.2857

0.03403

N-MeFBSE Alcohol(3)

0.3284

0.5395

0.2690

1.608

(1) Units of the calculated half-life is years at 25°C.

(2 ) Concentrations shown are quantitation limits, half-lives shown represent a "less than" value, see Appendix B for details.

(3) Half-life represents rate of formation and is calculated for the degradation of N-MeFBSEA.

(4) ND is Non-Detect, UND is undetermined.

ATTACHED DOCUMENTS : Fig 1 Hydrolysis of N-MEBSEA

Applicant's summary and conclusion

Conclusions:
Hydrolysis rates of N-MeFBSEA were calculated by monitoring the appearance of N-MeFBSE Alcohol as a function of pH. N-MeFBSEA was determined to have a hydrolysis half-life of 0.6049 years at pH 7 and 25°C.
Executive summary:

Hydrolysis study for 2-(N-methylperfluorobutanesulfonamido) ethyl acrylate (N-MeFBSEA) was performed according to the US EPA Test Guidelines OPPTS 835.2110 “Hydrolysis as a Function of pH”.

 

2-(N-methylperfluorobutanesulfonamido) ethyl acrylate (N-MeFBSEA) was suspended in buffers of pH 4,7 and 9 at a nominal concentration of 4 ppm, and was allowed to react for five days at 50°C. After the five-day reaction period, THF was added to the buffer containing vials as a dilution solvent to improve recoveries. Four targeted hydrolysis compounds were analyzed by HPLC/MS. Only N-MeFBSE Alcohol was found as hydrolysis product at pH 7, and was used to calculate the hydrolysis half life.

 

N-MeFBSEA has a hydrolytic half life of 0.6048 years at pH 7 at 25°C determined from the appearance of the degradation product 2-(N-methylperfluorobutanesulfonamido) ethyl alcohol. The measured half-life was longer under both acidic and basic conditions.

 

This is a guideline study conducted under GLP. Therefore, it is considered to be reliable without restriction.