Coke Check

Blood and urine are conventional matrices for drug testing, but both are biohazards – which has implications for storage and transport – and a potential invasion of privacy. “Fingerprint samples, on the other hand, are safe, easy to transport, and can be easily collected by non-medical staff,” says Catia Costa, investigator of a novel method that uses fingerprints to detect illicit drug use. Donor identity can be imbedded on the ridge of the sample to stop cheats, making it particularly useful in drug rehabilitation centers, jails, and probation services.

“We started by exploring a range of MS techniques: desorption electrospray ionization, matrix-assisted laser desorption ionization, liquid-extraction surface analysis, paper spray, and LC-MS,” says Costa. However, due to the “complex” nature of fingerprint samples (which compose sebaceous, eccrine and external contaminants), high-resolution MS (HRMS) was required to differentiate the sample components adequately. An extra layer of complication? The need to distinguish drug ingestion from environmental contamination.