Poster #110, UCSF
Biosurveillance of the San Francisco Drug Supply using LC-HRMS
Mentors: Emilio Mejia MS and Dr. Kara Lynch, PhD DABCC
San Francisco’s illicit drug supply is an ever changing landscape that requires constant monitoring in order to maintain the efficacy of harm reduction tactics. Anonymous biosurveillance allows us to monitor the drug supply via urine samples collected during opioid replacement therapy. Drug detection in a clinical toxicology setting relies on methods that balance speed, sensitivity, and precision. Our laboratory employs multiple mass spectrometry techniques, Liquid Chromatography High Resolution Mass Spectrometry (LC-HRMS) Direct Analysis in Real Time (DART‑MS) and LC-Triple Quadrupole (LC-QQQ-MS)—to detect drugs such as fentanyl, nicotine, THC, and other drugs in blood and urine. Each system has benefits and drawbacks, and are used to play to each strength. In this project, we focus on LC-HRMS to identify the many potential analytes in the drug supply. LC-HRMS is especially powerful for untargeted drug detection, where the goal is to screen for a wide range of substances without knowing exactly what’s in the sample. Its high mass resolution helps distinguish molecules that are nearly identical in mass, which is key when dealing with complex mixtures or new synthetic compounds. This Technique also allows researchers to build large spectral libraries that can be compared across samples, helping identify unknown compounds faster. This approach lets researchers detect unexpected or emerging drugs that might otherwise go unnoticed. By combining LC-HRMS data with other analytic tools, scientists can trace patterns in drug composition and even spot counterfeit or contaminated batches. Staying current with these trends helps clinicians and public health teams recognize shifts in drug use patterns and respond quickly. For example, by ensuring access to naloxone and other harm-reduction tools for opioid overdose therapy.