Picolinate PHP

Table 9-4. Monophenyl terephthalate (MPT ) and phenyl picolinate (PHP) are subject to mineral surface-catalyzed hydrolysis. Observations concerning the behavior of these two compounds in suspensions containing various mineral surfaces are summarized. 

Torrents, A., and A.T. Stone. 1991. Hydrolysis of phenyl picolinate (PHP) at the mineral/water interface. Environ. Sci. Technol. 25 143-149. 

These mechanisms have been used to rationalize the effect of mineral oxides on the hydrolysis rates of carboxylic acid esters. For example, suspensions of Ti02 and FeOOH dramatically accelerated the hydrolysis of phenyl picolinate (PHP) (Torrents and Stone, 1991). Suspensions of AI2O3 and Si02 had negligible effects on hydrolysis rates (Figure 2.16). 

Effect of various metal oxides on the loss of phenyl picolinate (PHP) from solution via hydrolysis. All suspensions contained 10 g/L oxide, 1 x10 M acetate buffer (pH 5.0) and 5x10 M NaCI. From Torrents and Stone (1991). (Reprinted by permission from the American Chemical Society). 

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