Determination of the distribution coefficient (logKd) of oxytetracycline, tylosin A, olaquindox and metronidazole in manure

Olaquindox (logKow=−2.3) and metronidazole (logKow=−0.1) both have low tendencies to sorp to particles in manure. This corresponds with the negative logKow values of these antibiotics. Tylosin (logKow=1.63) and oxytetracycline (logKow=−1.12) sorp relatively strongly to the manure particles and have logKd values between 1.5 and 2.0. The tendency to bind to manure was ranked after increasing binding as follows: metronidazole