Validation of a procedure for toxicants detection in baits and animal organs in case of suspected poisoning by using GC–MS and LC-MS/MS, as a part of systematic toxicological analysis based on 15 years of experience

The aim of this study was to describe a Systematic Toxicological Analysis (STA) procedure adopted for the determination of toxicants in baits or samples derived from suspected poisoned animals. Extraction and purification were based on a QuEChERS-like technique, while instrumental identification was conducted using both GC-MS and LC-MS/MS. The procedure was designed for the routine screening of 42 target toxicants, along with untargeted screening based on GC-MS with AMDIS program (Automated Mass Spectral Deconvolution and Identification System) and with Excalibur^TM software. Validation of the target toxicants was performed by calculating the limit of detection, specificity, matrix effect, and carry over, using fortified samples of liver, gastric content and sausage. Limits of detection ranged between 0.02 and 2.5 mg/Kg and no significant interfering peaks due to matrix were observed. Carry-over was noted at concentrations greater than tenfold 10 mg/L. The matrix effect was estimated for all the matrices, with the most significant effect observed for gastric content. The procedure was implemented in the laboratory to investigate authentic cases of animal poisoning, demonstrating that preliminary screening is crucial for reducing the criticalities such as response time and the suitability of analytes under investigation.