Residues of tritium-labeled morantel in lactating dairy cattle

Lynch, Martin J.; Mosher, Franklyn R; Burnett, Donald M.; Newby, T J

doi:10.1021/jf00075a017

Cited by 4 publications

(1 citation statement)

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“…23 However, morantel residue concentrations of 84 and 170 ng/ mL have been reported in dairy cattle milk and plasma, respectively. 24 As a consequence, morantel is subject to the USDA's Food Safety and Inspection Service National Residue Program, 25 the analytical testing program for residues in domestic and imported meat, which lists the lowest detectable limit (LDL) in cattle liver at 0.25 ppm. 26 In the United States, it has been estimated that on average 6600 kg of morantel is introduced into the environment every year, 20 where its presence could lead to morantel resistance in nematodes and other biota.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Optical Studies of the Agricultural Antibiotic Morantel Interacting with Silica/Water Interfaces

et al. 2005

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It is now known that the untreated discharge of pharmaceuticals into the environment can impact human health and development and lead to increased drug resistance in biota. Here, we present the first direct interface-specific studies that address the mobility of the widely used agricultural antibiotic morantel, which is commonly present in farm runoff. Surface-bound morantel was spectroscopically identified using second harmonic generation (SHG) via a two-photon resonance of its n-pi* transition and in the C-H stretching region by vibrational sum frequency generation (VSFG). Resonantly enhanced SHG adsorption isotherm measurements carried out at the silica/water interface between 6 x 10(-7) and 5 x 10(-5) M morantel concentration result in a free energy of adsorption of 42(2) kJ/mol at pH 7. Finally, real-time tracking of morantel interaction with the silica/water interface shows that the binding events are fully reversible, consistent with its high mobility in silica-rich soil environments. This work thus indicates that pharmaceuticals discharged into the environment can enter the groundwater supply of municipal water systems, at which point their removal is challenging. In addition, the high mobility of morantel in silica-rich soil environments could lead to developing increased interaction of this antibiotic with target organisms, which could respond by increased drug resistance.

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Section: Introductionmentioning

confidence: 99%