Figure 4.

Photodegradation of fipronil on corn leaves to the desulfinyl and detrifluoromethylsulfinyl derivatives. Time refers to the hours of exposure to sunlight. The results (n = 3) are given as percent composition of the recovered compounds without correction for volatility losses. Although not shown, fipronil sulfide and sulfone made up 7% of the composition at 93 h. Controls involving covered “dark” spots of the individual compounds revealed volatility losses over 93 h of 11%, 4%, and 21% for fipronil and its desulfinyl and detrifluoromethylsulfinyl derivatives, respectively.