title: Simplifying sample pretreatment: application of dried blood spot (DBS) method to blood samples, including postmortem, for UHPLC-MS/MS analysis of drugs of abuse.
abstract: The complexity of biological matrices, such as blood, requires the development of suitably selective and reliable sample pretreatment procedures prior to their instrumental analysis. A method has been developed for the analysis of drugs of abuse and their metabolites from different chemical classes (opiates, methadone, fentanyl and analogues, cocaine, amphetamines and amphetamine-like substances, ketamine, LSD) in human blood using dried blood spot (DBS) and subsequent UHPLC-MS/MS analysis. DBS extraction required only 100μL of sample, added with the internal standards and then three droplets (30μL each) of this solution were spotted on the card, let dry for 1h, punched and extracted with methanol with 0.1% of formic acid. The supernatant was evaporated and the residue was then reconstituted in 100μL of water with 0.1% of formic acid and injected in the UHPLC-MS/MS system. The method was validated considering the following parameters: LOD and LOQ, linearity, precision, accuracy, matrix effect and dilution integrity. LODs were 0.05-1ng/mL and LOQs were 0.2-2ng/mL. The method showed satisfactory linearity for all substances, with determination coefficients always higher than 0.99. Intra and inter day precision, accuracy, matrix effect and dilution integrity were acceptable for all the studied substances. The addition of internal standards before DBS extraction and the deposition of a fixed volume of blood on the filter cards ensured the accurate quantification of the analytes. The validated method was then applied to authentic postmortem blood samples.
authors.affiliation: Forensic Toxicology Laboratory, Institute of Public Health, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Odoardi
authors.affiliation: Forensic Toxicology Laboratory, Institute of Public Health, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Anzillotti
authors.affiliation: Forensic Toxicology Laboratory, Institute of Public Health, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome, Italy. Electronic address: sabina.stranorossi@rm.unicatt.it.
authors.forename: Sabina
authors.initials: S
authors.lastname: Strano-Rossi
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D059788:Dried Blood Spot Testing / Q000379:methods*; D053593:Forensic Toxicology / Q000379:methods; D006801:Humans; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods; D009294:Narcotics / Q000097:blood*
chemical_list: D009294:Narcotics
keywords: Dried blood spot (DBS); Forensic toxicology; LC–MS/MS; Sample preparation