Bis[2-[2-(1-methylethyl)-3-oxazolidinyl]ethyl] hexan-1,2-diylbiscarbamate

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-01-12

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Principles of method if other than guideline:

Hydrolysis tests at pH 4, 7 and 9 using FIMS (Flow Injection Mass Spectrometry) were performed. The hydrolysis tests indicated, how fast and completely the test item was degraded in presence of water (pH 4, 7 and 9), and if the hydrolysis reaction was acid-catalyzed. Therefore, short- and long-term measurements were performed.

GLP compliance:

yes

Remarks:

the study was conducted in equivalence conditions to good laboratory practice

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

The sample solution (100 μg/mL, dissolved in acetonitrile) was injected by a 500 μL syringe directly into the mass spectrometer at 10 μL/min (APCI, positive ion-mode).
- Instrument: LTQ-Orbitrap XL
- Resolution: 60000
- Tune: APCILF10_10-507_267.1.LTQTune

Buffers:

- Buffer at pH = 4, 7, 9

Details on test conditions:

HPLC-APCI-MS measurements:
Test item (non hydrolyzed sample):
For the HPLC-APCI-MS measurements test test item was dissolved and diluted in methanol (100 μg/mL).
- Column: Hypersil ODS (C18) 3u, 150 x 4.6 mm, Alltech
- Solvent: D: 1 mM NH4HCOO in MeOH
- Flow rate: 800 μL/min.
- Injection volume: 10 μL
- Instrument: LTQ-Orbitrap XL
- Resolution: R = 60000
- Detection: APCI, pos. Ion Mode, Full scan [m/z: 80-1200]
- Tune-Method: APCIHF500_10-692_ACN.LTQTune

Test item (hydrolyzed sample):
For the HPLC-APCI-MS measurements the test item was dissolved in ACN, diluted and hydrolyzed in 0.1 % TFA in water / 0.1 % TFA in ACN = 80:20 (10 μg/mL).
- Column: Synergi 4u Hydro-RP 80A, 75 x 4.6 mm (Phenomenex)
- Solvents: A: 0.1 % trifluoroacetic acid (TFA) in water; B: 0.1 % trifluoroacetic acid (TFA) in ACN
- Gradient: [min] / % A / % D
0.0 / 95 / 5
1.0 / 95 / 5
6.0 / 0 / 100
8.0 / 0 / 100
8.5 / 95 / 5
12.0 / 95 / 5
- Flow rate: 600 μL/min
- Injection volume: 10 μL
- Instrument: LTQ-Orbitrap XL (high resolution mass spectrometer)
- Resolution: R = 60000
- Detection: APCI, positive ion mode, full scan [m/z: 80-1200]

Duration:

0.017 min

pH:

4

Initial conc. measured:

100 other: µg/mL

Duration:

0.017 min

pH:

7

Initial conc. measured:

100 other: µg/mL

Duration:

0.017 min

pH:

9

Initial conc. measured:

100 other: µg/mL

Duration:

2 min

pH:

4

Initial conc. measured:

1 000 other: μg/mL

Duration:

18 h

pH:

4

Initial conc. measured:

1 000 other: μg/mL

Duration:

2 min

pH:

7

Initial conc. measured:

1 000 other: μg/mL

Duration:

18 h

pH:

7

Initial conc. measured:

1 000 other: μg/mL

Duration:

2 min

pH:

9

Initial conc. measured:

1 000 other: μg/mL

Duration:

18 h

pH:

9

Initial conc. measured:

1 000 other: μg/mL

Positive controls:

not specified

Negative controls:

not specified

Test performance:

FIMS:
The mass spectrum of the test substance sample showed the expected mass at m/z = 487.34811. Based on the accurate mass measured, the chemical formula of C24H46O6N4 and 4 ring double bond equivalents (RDB’s: 2 double bonds and two rings) were calculated for the neutral molecule.
The mass spectrum of the main component of the test substance (MS/MS of m/z = 487.35) showed two fragments at m/z = 415.29150 and 372.24933.

Transformation products:

yes

No.:

#1

Key result

pH:

4

Temp.:

20 °C

DT50:

< 2 min

Key result

pH:

7

Temp.:

20 °C

DT50:

< 2 min

Key result

pH:

9

Temp.:

20 °C

DT50:

< 18 h

Details on results:

The short term measurements indicated that the test substance hydrolyzed faster at pH 4 than at pH 7 and 9.
The long term measurements indicated that the hydrolysis reaction occured at pH 4, 7 and 9 within a few minutes.
The compounds (partially hydrolyzed test substance; [MH+] = 433.3 and fully hydrolyzed test substance, [MH+] = 379.3) and isobutyraldehyde (CAS 78-84-2) were formed during the hydrolysis reaction of the test item. Furthermore, fragments of fully hydrolyzed tets substance with m/z = 274.2 and m/z = 143.1 were observed.

HPLC-APCI-MS results:
- Test item (non hydrolyzed sample):
The HPLC-MS measurements showed, that only a very small amount of hydrolyzed products are present in test substance. Due to its very low hydrolysis stability, a water free mobile phase has to be used to separate the test substance properly. Under these conditions no chromatographic method could be developed to separate the main compound from other compounds except its hydrolysis products. Therefore the test substance was completely hydrolyzed and a chromatographic method was developed to separate the hydrolyzed main compound from its potential by-products.

- Test item (hydrolyzed sample)
The mass spectrum of the fully hydrolyzed test substance showed the expected mass at m/z = 379.25360 (corresponding to the fully hydrolyzed test item). Based on the accurate mass measured, the chemical formula of C16H34O6N4 and 2 ring double bond equivalents (RDB’s: 2 double bonds) were calculated for the neutral molecule.
Based on the extracted ion chromatograms no mono and non-hydrolyzed test substance could be observed. Traces of diethanolamine (m/z=106.1)were found.

- FIMS data showed that at pH = 4 after 2 minutes and 18 hours no signals of the test substance could be detected. Thus the hydrolysis half-live at pH = 4 was considered to be < 2 minutes.

- FIMS data showed that at pH = 7 after 2 minutes and 18 hours no signals of the test substance could be detected. Thus the hydrolysis half-live at pH = 7 was considered to be < 2 minutes.

- FIMS data showed that at pH = 9 after 18 hours no signals of the test substance could be detected. Thus the hydrolysis half-live at pH = 9 was considered to be < 18 h.

Validity criteria fulfilled:

not specified

Conclusions:

The hydrolysis of the test substance (bis[2-[2-(2-(1-methylethyl)-3-oxazolidinyl]ethyl] hexane-1,2-diylbiscarbamate) at pH = 4, 7 and 9 was investigated using FIMS (Flow Injection Mass Spectrometry). Short- and long-term measurements show that the test substance hydrolysed faster at pH 4 than at pH 7 and 9 and that the hydrolysis reaction occured at pH 4, 7 and 9 within a few minutes.

Executive summary:

The hydrolysis of the test substance (bis[2-[2-(2-(1-methylethyl)-3-oxazolidinyl]ethyl] hexane-1,2-diylbiscarbamate) at pH = 4, 7 and 9 (at room temperature) was investigated using FIMS (Flow Injection Mass Spectrometry). Short- and long-term measurements show that the test substance hydrolysed faster at pH 4 than at pH 7 and 9 and that the hydrolysis reaction occured at pH 4, 7 and 9 within a few minutes. The compounds (partially hydrolysed test substance; [MH+] = 433.3 and fully hydrolysed test substance, [MH+] = 379.3) and isobutyraldehyde (CAS 78-84-2) were formed during the hydrolysis reaction of the test item. Furthermore, fragments of fully hydrolyzed tets substance with m/z = 274.2 and m/z = 143.1 were observed.

FIMS data showed that at pH = 4 and 7 after 2 minutes and 18 hours no signals of the test substance could be detected. Thus the hydrolysis half-lives at pH = 4 and 7 were considered to be <2 minutes. At pH = 9 after 18 hours no signals of the test substance could be detected. Thus the hydrolysis half-live at pH = 9 was considered to be <18 h.

As worst case value for chemical safety assesment a half-life of 2 minutes at 20 °C was used as key value.

Description of key information

The hydrolysis of the test substance (bis[2-[2-(2-(1-methylethyl)-3-oxazolidinyl]ethyl] hexane-1,2-diylbiscarbamate) at pH = 4, 7 and 9 was investigated using FIMS (Flow Injection Mass Spectrometry). Short- and long-term measurements show that the test substance hydrolysed faster at pH 4 than at pH 7 and 9 and that the hydrolysis reaction occured at pH 4, 7 and 9 within a few minutes.

Key value for chemical safety assessment

Half-life for hydrolysis:

2 min

at the temperature of:

20 °C

Additional information

The hydrolysis of the test substance (bis[2-[2-(2-(1-methylethyl)-3-oxazolidinyl]ethyl] hexane-1,2-diylbiscarbamate) at pH = 4, 7 and 9 (at room temperature) was investigated using FIMS (Flow Injection Mass Spectrometry). Short- and long-term measurements show that the test substance hydrolyzed faster at pH 4 than at pH 7 and 9 and that the hydrolysis reaction occured at pH 4, 7 and 9 within a few minutes. The compounds (partially hydrolysed test substance; [MH+] = 433.3 and fully hydrolysed test substance, [MH+] = 379.3) and isobutyraldehyde (CAS 78-84-2) were formed during the hydrolysis reaction of the test item. Furthermore, fragments of fully hydrolysed tets substance with m/z = 274.2 and m/z = 143.1 were observed.

FIMS data showed that at pH = 4 and 7 after 2 minutes and 18 hours no signals of the test substance could be detected. Thus, the hydrolysis half-lives at pH = 4 and 7 were considered to be < 2 minutes. At pH = 9 after 18 hours no signals of the test substance could be detected. Thus, the hydrolysis half-live at pH = 9 was considered to be <18 h.

As worst case value for chemical safety assesment a half-life of 2 minutes at 20 °C was used as key value.