Collin Kielty (He/Him) is a research associate at the Vancouver Island Drug Checking Project located in so-called Victoria, British Columbia, Canada, on the lands of the lək̓ʷəŋən and W̱SÁNEĆ People. He is a "lost astrophysicist" who has found his way into community-based drug checking and harm reduction.

Community-based drug checking services are a harm reduction practice aimed at people who use drugs that can provide compositional information about the unregulated supply; information that may affect dosing, minimize the risk of accidental poisoning, facilitate market intervention, and inform product quality control. While common drug checking technologies such as FTIR spectroscopy and immunoassay strip tests have been widely adopted within point-of-care drug checking services, a majority of these technologies lack the sensitivity required for the detection and/or quantification of low-concentration drugs. Here we overview the use of on-site paper spray mass spectrometry (PS-MS) for trace detection of low-concentration drugs within complex street sample matrices collected at a community-based drug checking service in Victoria, British Columbia, Canada. The quantitative capabilities and low detection limits demonstrated by PS-MS help address the challenges faced by other existing on-site drug checking methods, while also offering a highly flexible platform that can be adapted to respond to the rapid changes observed within the unregulated market. Guided by peer partners with invaluable drug knowledge, local suppliers with a commitment to quality control, drug seizure data, and academic literature, we have created methodology for PS-MS that includes targeted quantitative measurement of 103 drugs down to 0.01% weight/weight concentration, an untargeted full scan to assist in identifying unknown/unexpected components, and the adaptability to add new compounds as the market changes. Given the high degree of volatility observed within the illicit opioid supply in British Columbia, the ever changing combinations of low-concentration novel fentanyl analogues, non-medical benzodiazepines, and other potent compounds that may have unpredictable and dangerous consequences for people who use drugs, paper spray mass spectrometry serves as a valuable point-of-care tool to provide critical information on the unregulated market that people who use drugs, and people who sell drugs, are forced to exist within.