Target and non-target analytical method for potential hazardous substances in livestock and pet hair using liquid- and gas chromatography quadrupole time-of-flight mass spectrometry

Extraction using acetonitrile and water and quadrupole time-of-flight mass spectrometry (LC and GC-QTOF/MS) techniques were used to screen for potential hazardous substances in livestock and pet hair. In addition, LC-MS/MS and GC-MS/MS techniques were used for verification of the analytical method and quantitative analysis of pesticides, veterinary drugs, mycotoxins and antioxidants in hair. Optimized sample preparation involves extracting 0.05 g of sample with 0.6 mL of ACN and 0.4 mL of distilled water. In addition, the two layers were separated by adding 0.1 g of NaCl. Then, both the ACN and water layers were analyzed by LC-TOF/MS, and the ACN layer was analyzed by GC-TOF/MS. Most of the matrix effects of livestock and pet hair were less than 50%, but some matrices and components showed high results, so matrix matching correction was applied for more precise quantification. Method validation was performed for 394 constituents (293 pesticides, 93 veterinary drugs, 6 mycotoxins and 2 preservatives) in dog, cat, cow and pig hair and chicken and duck feathers. All components showed good linearity (r2 ≥0.98) in the developed assay. The quantification limit of all compounds was set at 0.02 mg/kg, which is the lowest level that satisfies the recovery rate standard. The recovery experiment was repeated 8 times at 3 concentrations. Most of the components were extracted with the ACN layer, and the recovery rate was 63.35-119.98%. In order to confirm the efficiency of extracting harmful substances from actual samples, 30 hairs of livestock and pets were screened.

Comparison of human and animal hair - A microscopical analysis

For nearly a century, hairs of animals and humans were employed in forensic research. It is found to be stable in certain environments, and thus, they are frequently retrieved at scenes of crime, and it is important to verify whether they are either human or animal. The present research was done at comparing the morphological differences among human hair and animal hair using a stereomicroscope. Samples of hair forming the outer coat of some autochthonous domestic and human remnants were evaluated in this study. Long strands of guard hair shaft were investigated by stereomicroscope accordingly. Microphotographs were taken in an iPad camera. The microscopic characteristics of cat hair samples showed the presence of small spikes on the surface, whereas the human hair sample showed a smooth appearance with no irregularities. The microscopic analyses of the human hair sample and cat hair sample under stereomicroscope suggest hair samples can be used as forensic evidence in crime scene investigation. The comparison of both the hair samples was done, and the differences were significantly evident.