Determination of residue levels of rodenticide in rodent livers offered novel diphacinone baits by liquid chromatography-tandem mass spectrometry.

A specific and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of the anticoagulant rodenticide diphacinone (DPN) in mouse and rat liver. Tissue samples were extracted with a mixture of water and acetonitrile containing ammonium hydroxide. The extracted sample was cleaned up with a combination of liquid-liquid partitioning and dispersive solid phase extraction.

Determination of residue levels of the avicide 3-chloro-4-methylaniline hydrochloride in red-winged blackbirds (Agelaius phoeniceus) by gas chromatography-tandem mass spectrometry.

The avicide 3‑chloro‑4‑methylanaline hydrochloride (chloro‑p‑toluidine hydrochloride, CPTH, DRC-1339) is used to control pest bird species that damage agricultural crops. A specific and sensitive gas chromatography-tandem mass spectrometry method was developed and validated for the determination of CPTH in avian breast muscle, GI tract, kidney, and liver. Tissue samples were extracted with a solution of acidified water and acetonitrile.

Determination of 20, 25-diazacholesterol in avian matrices by high performance liquid chromatography/tandem mass spectrometry.

Wildlife contraceptives are an emerging tool for minimizing human-wildlife conflicts. One promising avian contraceptive compound, 20,25-diazacholesterol (DAC), reduces fertility by inhibiting cholesterol synthesis. A reliable analytical method for DAC was required in support of its registration for use as a reproductive control agent in pest bird species.

Toxicokinetics and coagulopathy threshold of the rodenticide diphacinone in eastern screech-owls (Megascops asio).

In the United States, new regulations on second-generation anticoagulant rodenticides will likely be offset by expanded use of first-generation anticoagulant rodenticides. In the present study, eastern screech-owls (Megascops asio) were fed 10 µg diphacinone/g wet weight food for 7 d, and recovery was monitored over a 21-d postexposure period. By day 3 of exposure, diphacinone (DPN) was detected in liver (1.

Absorption, distribution, and excretion of [14C]-3-chloro-4-methylaniline hydrochloride in two species of birds following a single oral dose.

Ring-labeled [14C]-3-chloro-4-methylaniline hydrochloride (250 microg per bird) was delivered to 21 red-winged blackbirds (Agelaius phoeniceus) and 21 dark-eyed juncos (Junco hyemalis) via oral gavage, and the distribution and excretion of radioactivity were determined at 15 and 30 min and 1, 4, 8, 12, and 24 h (n = 3 per time point). Direct measurement of radioactivity as well as measurement following combustion was accomplished using a liquid scintillation counter. Elimination from most tissues followed a two-compartment model, with very rapid elimination occurring between time 0 and 4 h and a much slower elimination phase occurring after that.

Desmosterol: a biomarker for the efficient development of 20,25-diazacholesterol as a contraceptive for pest wildlife.

20,25-Diazacholesterol is being evaluated as a contraceptive for the nonlethal control of avian and mammalian wildlife pests. The identification of an analyte in blood which was highly correlated with absorbed dose and efficacy is valuable for determining effective formulations and dosing variables. Such an analyte or biomarker is also valuable for determining the percentage of pest populations that consume an effective dose of the active ingredient in the field.