{"doi":"10.1021/jasms.1c00267","title":"Use of Diagnostic Ions for the Detection of Fentanyl Analogs in Human Matrices by LC–QTOF","abstract":"To combat the ongoing opioid epidemic, our laboratory has developed and evaluated an approach to detect fentanyl analogs in urine and plasma by screening LC-QTOF MS/MS spectra for ions that are diagnostic of the core fentanyl structure. MS/MS data from a training set of 142 fentanyl analogs were used to select the four product ions and six neutral losses that together provided the most complete coverage (97.2%) of the training set compounds. Furthermore, using the diagnostic ion screen against a set of 49 fentanyl analogs not in the training set resulted in 95.9% coverage of those compounds. With this approach, lower reportable limits for fentanyl and a subset of fentanyl-related compounds range from 0.25 to 2.5 ng/mL in urine and 0.5 to 5.0 ng/mL in plasma. This innovative processing method was applied to evaluate simulated exposure samples of remifentanil and carfentanil in water and their metabolites remifentanil acid and norcarfentanil in urine. This flexible approach enables a way to detect emerging fentanyl analogs in clinical samples.","journal":"Journal of the American Society for Mass Spectrometry","year":2021,"id":181616,"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":16,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9406,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":733255,"name":"Rebecca L. Shaner","orcid":null,"position":1,"is_corresponding":false},{"id":733256,"name":"Logan C. Krajewski","orcid":null,"position":2,"is_corresponding":false},{"id":733257,"name":"William Bragg","orcid":null,"position":3,"is_corresponding":false},{"id":545370,"name":"Rudolph C. Johnson","orcid":null,"position":4,"is_corresponding":false},{"id":733258,"name":"Elizabeth I. Hamelin","orcid":null,"position":5,"is_corresponding":false},{"id":479820,"name":"Kenneth D. Swanson","orcid":null,"position":0,"is_corresponding":true}],"reference_count":28,"raw_metadata":null,"created_at":"2026-07-18T23:48:05.146883Z","pmid":"34793156","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":[]}