Reaction products of dimethyl phosphonate with 2-alkyl-2-alkylpropanediol and alkanediol

Hydrolysis

Description of key information

It was noted that the correlation between hydrogen ion concentration and time was stronger at 30 °C for each pH level tested, and the strongest correlation was found in pH 7. This information supports the preliminary observations indicating the material may undergo hydrolysis in water (OECD 111).

Additional information

GUIDELINE

The investigation was performed in accordance with Organization for Economic Cooperation and Development (OECD) Guideline for the Testing of Chemicals. Hydrolysis as a Function of pH, OECD Guideline No. 111 (April 13, 2004).

 

METHODS

A preliminary test of test item stability in water was conducted during examination of water solubility and showed an increase of hydrogen ion concentration over time, which indicated possible hydrolysis. Additional testing was performed in sterile aqueous buffers prepared at pH 4, 7, and 9 at three temperatures (10, 20, and 30°C).

 

Test solutions were prepared in pH 4, 7, and 9 buffers at approximately 0.5 mg/mL by weighing 0.5 g into each of 3, 1-L autoclaved volumetric flasks and bringing to volume with the respective buffers.

Each dosing solution was distributed into an appropriate number of autoclaved 2-dram vials, which were filled leaving no headspace and sealed with PTFE lined caps. Subsets of vials for each pH were placed in temperature-controlled chambers set to maintain 10, 20, and 30°C. The pH of each remaining dosing solution was measured. Vials containing buffers with no test material were prepared in the same way as the samples to check for background contamination.

 

Sampling for pH 4 at all temperatures was performed after approximately 1, 2, 3, 4, 5, 6, 23, 29, 48, and 53 hours by removing two vials at random and measuring pH and temperature immediately. This process above was repeated for pH 7 and 9 after approximately 2, 4, 5, 23, 29, 48, and 53 hours.

 

Following completion of the test period, the vials containing each buffer which had been stored at 30°C were removed for sterility check. An aliquot (1 mL) of each buffer was applied to individual 3M petrifilm plates while contained in a biological safety cabinet. The plates were placed in an incubator set at 35 °C for approximately 48 hours before being removed and visually observed for the presence of colonies.

 

RESULTS

It was noted that the correlation between hydrogen ion concentration and time was stronger at 30 °C for each pH level tested, and the strongest correlation was found in pH 7. This information supports the preliminary observations indicating the material may undergo hydrolysis in water.

 

CONCLUSION

It was noted that the correlation between hydrogen ion concentration and time was stronger at 30 °C for each pH level tested, and the strongest correlation was found in pH 7. This information supports the preliminary observations indicating the material may undergo hydrolysis in water.