The U.S. Fish and Wildlife Service Forensics Laboratory (USFWS) in Ashland, Oregon is just like any crime laboratory. Forensic lab analysts examine, identify and compare evidence using traditional instrumentation to link suspect, victim and crime scene with physical evidence. The only caveat here is that the victim is an animal, not a human.
Just as forensic analysts in traditional labs work to protect humans by bringing murderers, rapists and other criminals to justice, USFWS protects endangered species from dangerous criminals. At Pittcon 2020, executives from JEOL spoke about the work they do with USFWS to ensure the safety of rhinoceros, who are among the most trafficked animals in the world.
On the black market, a single large rhino horn can sell for as much as $100,000. It is highly valued in some cultures for its medicinal purposes and for being a symbol of high social status.
Wildlife trade is the fourth largest illegal industry worldwide, behind narcotics, counterfeiting and human trafficking. When items suspected of being made from protected species are seized at airports, borders, and shipping docks and cannot be positively identified, the inspectors send them to USFWS. The analysts use all the typical forensic methods including morphology, DNA analysis and chemical analysis to verify what the animal or plant is, how it was killed and determine its origin. But often it's the chemical composition that provides the positive identification needed.
For the past three years, USFWS lab has used the JEOL AccuTOF-DART, a mass spectrometer equipped with a JEOL-patented ion source (DART) that makes it possible to analyze a sample without altering it or having to go through any special sample preparation techniques. DART can almost instantly detect the chemical fingerprint of contraband and produce a mass spectrum showing the active ingredient.
In the case of illegal rhino horn smuggling, researchers are looking for rhinoceros horn keratin, which can be complicated by the presence of alternative/imitation keratin. In a study published in Rapid Communications in Mass Spectrometry, USFWS researchers collected the spectra of 156 keratin samples from all five rhinoceros species (horn keratin), eight genera of bovids (horn keratin), domestic horses (hoof keratin), and all extant species of pangolins (scale keratin). Fisher ratio analysis identified the most important ions that characterized each class and those ions were used to create a training model, which comprised 143 spectra.
Spectra collected for each taxonomic group was distinctive. The chemotypes demonstrated that the spectra of rhinoceros, bovids, and domestic horse are similar to each other, whereas the chemotypes of pangolins show a different chemical profile. During analysis, the researchers’ training model resolved each taxonomic group: 95% of samples were correctly assigned using leave‐one‐out cross validation. The 13 blind samples not used in model development were all correctly classified to taxonomic source.
The work sets an important precedent for wildlife researchers, who now have a mass spec standard for taxonomic differentiation of different sources of keratin.
*Check back with Forensic next Monday for an article about how USFWS forensic scientists are working to correct misinformation and save the pangolin, the most trafficked animal in the world.
Photo: Robert (Chip) Cody (JEOL) with Edgard (Ed) Espinoza (USFWS Forensic Lab) with a rhino horn and the AccuTOF-DART mass spectrometer. Credit: JEOL