A common analytical method for detecting opioids in blood, saliva and urine samples is liquid chromatography mass spectrometry (LCMS). Clinic-based LCMS screening offers excellent detection and sensitivity, but sample collection and preparation is complicated and time-consuming. In addition to body fluids, opioids are also distributed in the skin. So, William Clarke, Livia Eberlin and colleagues came together to modify their handheld MasSpec Pen into a modular tool that quickly collects molecules from the skin’s surface to be tested for opioids, eliminating the need for additional sample prep.
The new version of the MasSpec Pen delivers a small droplet of water and ethanol to the surface of the skin. While it sits there, the liquid extracts molecules that could indicate past drug use. After 3 seconds, the liquid droplet is sucked up by the pen into a collection vial. The sample can be immediately analyzed by electrospray ionization mass spectrometry or stored for future analysis.
After successful proof-of-concept demonstrations on patches of human skin, the team tested the MasSpec Pen on the arm or hand of eight participants with known exposure to fentanyl and hydromorphone. When the researchers compared the new collection tool’s skin sample data to traditionally collected urine and saliva data, they found:
- Fentanyl in seven of the MasSpec Pen skin samples but no hydromorphone.
- Fentanyl and hydromorphone in all eight urine samples.
- Fentanyl in five saliva samples (one sample could not be tested) and hydromorphone in four saliva samples.
Although the samples collected by the MasSpec Pen did not have the same level of detection as the urine and saliva samples, the device’s easy use and portability show promise for future development. The researchers note that discrepancies might stem from the time of drug ingestion relative to when the testing was performed. The team’s future studies may explore the impact of skin type, skin cleanliness and extent of drug exposure on the MasSpec Pen detection limits and analysis of opioids.
Republished courtesy of ACS