An Easy Procedure to Quantify Anticoagulant Rodenticides and Pharmaceutical Active Compounds in Soils.

A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction was validated for the extraction of seven coumarin anticoagulant rodenticides (ARs) and 36 pharmaceutical active compounds (PhACs) residues in soil samples using liquid chromatography tandem mass spectrometry (LC-MS/MS). The aim of this work was to develop a method for the monitoring of these compounds in agricultural lands as well as in forensic applications for the determination of ARs poisoning. As far as is known, this is the first time that a QuEChERS-based method is used for the extraction of ARs in soil, as well as on such a quantity of PhACs. A matrix effect study was carried out on samples of soil devoted to agriculture in the midland area of the Canary Islands (clay loam type). It was in house validated (accuracy, precision, and linearity) at seven spiked levels between 0.5 and 50 ng g-1. The limits of quantification (LOQ) ranged between 0.5 and 50.0 ng g-1 and the limits of detection (LOD) ranged from 0.024 to 6.25 ng g-1. The method was then successfully used for both the determination of the target analytes in the soils from the agricultural plots that had been irrigated with regenerated water, and in the soil collected from underneath wild bird carcasses (which had been the subject of forensic investigation).

Importance of segmental hair analysis in a suspected case of attempted homicide by flocoumafen and difenacoum.

The 4-hydroxycoumarin derivatives are the most used rodenticides and act as classical anticoagulants, interfering with the production of clotting factors in liver by antagonizing the action of vitamin K reductase, thereby inhibiting recycling of vitamin K1, involved in activation of blood clotting factors, resulting in massive bleeding. In this paper, we present the case of a 72-year old man providing abnormal coagulation parameters (PT-INR between 16.1 and 19.1) after hospitalization. Blood samples tested positive for flocoumafen and difenacoum, two superwarfarin rodenticides. Patient's hair specimens, sampled 19 days after his hospitalization, showed that traces of both difenacoum and flocoumafen were detected in the first 1 cm; in the intermediate segments (1-2 and 2-3 cm), both difenacoum and flocoumafen were absent, while in the distal segment (3-4.5 cm), only difenacoum was found, but in significant amounts (140 pg/mg). Exposure to difenacoum in the past months, at least 4-5 before hospitalization, was confirmed by the presence of the rodenticide in the distal segment. Moreover, among the seized material, two specimens resulted compatible with the two rodenticides.

Quantitative method for analysis of six anticoagulant rodenticides in faeces, applied in a case with repeated samples from a dog.

BACKGROUND: Accidental poisoning with anticoagulant rodenticides is not uncommon in dogs, but few reports of the elimination kinetics and half-lives in this species have been published. Our objectives were to develop and validate a new method for the quantification of anticoagulant rodenticides in canine blood and faeces using reversed phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and apply the method on a case of anticoagulant rodenticide intoxication. RESULTS: Sample preparation was liquid-liquid extraction. Six anticoagulant rodenticides were separated using a UPLC® BEH C18-column with a mobile phase consisting of 5 mM ammonium formate buffer pH 10.2 and methanol. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions. The limits of quantification were set at the levels of the lowest calibrator (1.5-2.7 ng/mL or ng/g). The method was successfully applied to a case from a dog accidentally poisoned with anticoagulant rodenticide. Coumatetralyl and brodifacoum concentrations were determined from serial blood and faecal samples. A terminal half-life of at least 81 days for coumatetralyl in blood was estimated, which is longer than previous reported in other species. A slow elimination of brodifacoum from the faeces was found, with traces still detectable in the faeces at day 513. CONCLUSIONS: This study offers a new method of detection and quantification of six frequently used anticoagulant rodenticides in canine faeces. Such drugs might cause serious health effects and it is important to be able to detect these drugs, to initiate proper treatment. The very long elimination half-lives detected in our study is important to be aware of in assessment of anticoagulant rodenticide burden to the environment.