Analysis of multiple anticoagulant rodenticides in animal blood and liver tissue using principles of QuEChERS method.

A quick and easy method for the analysis of anticoagulant rodenticides in blood or tissue using principles of dispersive solid-phase extraction (dSPE), commonly known as QuEChERS (short for quick, easy, cheap, effective, rugged, and safe), was developed. Briefly, a combination of magnesium sulfate, PSA, florisil, and basic alumina was used to cleanup blood samples. Further, to cleanup liver tissue samples, C(18) sorbent was included along with the previously mentioned. The samples were analyzed using high-performance liquid chromatography equipped with a reversed-phase C(18) column (150 x 4.6 mm, 5-microm particle size) and a UV and fluorescence detector. The mobile phase consisted of 0.03 M tetrabutylammonium hydroxide (TBA) adjusted to pH 7/methanol (1:1, v/v) as solvent A and methanol as solvent B in a gradient run. The method detection limit was as low as 10 ng/mL for brodifacoum and difenacoum in blood and 10 ng/g in liver; 50 ng/mL for bromadiolone, difethialone, and chlorphacinone in blood and similarly 50 ng/g in liver; and 100 ng/mL for coumafuryl, pindone, warfarin, and diphacinone in blood and 100 ng/g in liver samples. A number of clinical samples of both blood and liver were analyzed; the comparison of this modified QuEChERS and traditional solid-phase extraction data was found to be in close agreement. This method resulted in drastic reduction in processing time and solvent cost both in terms of consumption and disposal, thus making it an attractive alternative to the traditional solid-phase extraction.