Photochemical degradation of a toxic organophosphorous analog (PMSF) in microemulsion media

A study has been made of the photodegradation of an analog, phenylmethylsulphonyl fluoride (PMSF), of a toxic chemical warfare agent. The agent was solubilized in a water-in-oil surfactactant stabilized microemulsion system comprising sodium dodecyl sulphate, pentanol and water. Loss of the parent PMSF molecule upon exposure of the system to UV irradiation was monitored by ¹⁹F NMR spectroscopy. Consideration of the changes in the chemical shifts, splittings in conjunction with GC/Mass spectroscopy data strongly suggest the degradation leads to partial fluorination of pentanol. Analysis of peak areas also indicates the formation of volatile degradation products such as HF. The addition of TiO₂ or hydroquinone to the system did not appreciably change the overall amounts of degradation. The results are interpreted in terms of the possible radical based reaction pathways and show that such a microemulsion medium to have significant potential as a vehicle for effecting such a degradation process.