{"doi":"10.1111/dar.70037","title":"Point‐Of‐Care Drug‐Checking: Assessing the Rhode Island Drug Supply Using <scp>FTIR</scp> Spectroscopy to Detect Fentanyl, Xylazine and Other Substances","abstract":"INTRODUCTION: The illicit drug supply constantly fluctuates, with new adulterants and unexpected mixtures creating uncertainty. Point-of-care drug-checking services are vital in reducing overdose risk and other harms by providing real-time analysis, harm reduction education and links to care. This study aimed to characterise the local drug supply using Fourier transform infrared (FTIR) spectroscopy, complemented by Liquid Chromatography-Quadrupole time-of-flight Mass Spectrometry (LC-QToF-MS) for additional context, from drug residues collected through a drug-checking program within a Rhode Island harm reduction site. METHODS: From January to May 2023, 100 samples were analysed using FTIR and sent for additional qualitative and semi-quantitative testing via LC-QToF-MS. Substances detected by both methods were summarised by prevalence, mixture composition and alignment with self-reported drug categories. RESULTS: Fentanyl (53%) and cocaine (48%) were the most prevalent substances detected by FTIR, followed by xylazine (10%) and methamphetamine (8%). Cross-category analysis revealed cocaine in 36% of opioid-reported samples and fentanyl in 3% of self-reported cocaine samples, underscoring the mixed nature of the supply. We found the local fentanyl supply (n = 57) showed high variability, with 15 additional components detected by FTIR, including xylazine (19.3%). DISCUSSION AND CONCLUSIONS: These findings provide a snapshot of the unpredictable and highly mixed nature of the Rhode Island drug supply defined by stimulant-opioid overlaps, xylazine adulteration and the presence of cocaine across drug categories. By pairing real-time FTIR with laboratory-based analysis, we provided actionable information back to service users while also uncovering deeper patterns in local drug trends.","journal":"Drug and Alcohol Review","year":2025,"id":524473,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9517,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1030842,"name":"Jessica Tardif","orcid":"0000-0003-1147-479X","position":1,"is_corresponding":false},{"id":1030843,"name":"Erin Thompson","orcid":"0000-0001-6451-2679","position":2,"is_corresponding":false},{"id":1041444,"name":"Adina Badea","orcid":"0000-0002-7077-2810","position":3,"is_corresponding":false},{"id":1041443,"name":"Alexis Morales","orcid":"0000-0002-5437-9656","position":4,"is_corresponding":false},{"id":1397981,"name":"Cole Jarczyk","orcid":"0000-0002-0464-8897","position":5,"is_corresponding":false},{"id":268926,"name":"Traci C. Green","orcid":"0000-0001-9105-6904","position":6,"is_corresponding":false},{"id":1055925,"name":"Rachel Serafinski","orcid":"0000-0002-0733-4404","position":7,"is_corresponding":false},{"id":1397982,"name":"Michelle McKenzie","orcid":"0000-0001-5047-4413","position":8,"is_corresponding":false},{"id":247848,"name":"Ju Nyeong Park","orcid":"0000-0001-6490-9887","position":9,"is_corresponding":false},{"id":1233758,"name":"Merci Ujeneza","orcid":null,"position":0,"is_corresponding":true}],"reference_count":34,"raw_metadata":null,"created_at":"2026-07-19T02:50:12.083054Z","pmid":"40977066","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}