Peroxides have a wide range of uses in organic synthesis, but there are also great safety hazards, especially solvents such as ether, tetrahydrofuran and isopropyl alcohol, which are easy to produce organic peroxides after a long time, and if they are ignored during use, it is easy to explode. It is important to find a reliable, universal and sensitive method for the detection of organic peroxides for laboratory safety.
In 2020, Org.Process Res.Dev. (Org.Process Res.Dev. 2020, 24, 7, 1321-1327) published a method for quantitative detection of ppm organic peroxides based on liquid chromatography-ultraviolet (LC-UV). The method is simple and sensitive. The transition metal catalyzed the reaction of peroxides with sulfides to form sulfoxides. The content of sulfoxides was indirectly confirmed by LC detection. The detection limit of sulfoxides reached 1 μg/mL using ordinary C18 column and UV detector.
Through experiments, the researchers determined that pentavalent vanadium OV(OiPr)3 as the catalyst, benzyl phenyl sulfide as the substrate, LC to detect the content of sulfoxide product 3 was the best combination, and the reaction could be completed within 4 hours. The researchers used this method to study THF and MeTHF and found that:
1.BHT can effectively inhibit the production of peroxide. During the six-week experiment, whether it is stored in nitrogen or air, transparent glass or brown glass, the increase of peroxide content is less than < 10 ppm;
- THF and MeTHF without BHT can be safely stored in nitrogen atmosphere;
- After exposure to air in both brown and clear glass bottles, the peroxide content of THF and MeTHF increased, and the peroxide increase in MeTHF was faster than that in THF.
