Comprehensive Toxicology and TDM by DBS
This presentation describes our HPLC/MS/MS method that quantifies hundreds of drugs from a single dried blood spot (DBS). We will also present correlation data from over 1,000 paired urine and DBS forensic samples, demonstrating the differences between the matrices for detection of substance exposure.
The analysis is accomplished through optimization of method parameters using the latest generation of HPLC/MS/MS triple quadrupole instruments. The DBS and urine samples were contemporaneously observed collections from 60 days of report and community correction centers across five states.
DBS samples are collected on stabilized filter paper and dried. They are punched into microtiter plates where internal standard is added, and the analytes are extracted. The analysis is performed using an Agilent Infinity III LC system and Agilent 6495D triple quadrupole LC/MS system.
The analyte list starts with the ~100 typical drugs monitored in pain management and forensic testing and has been expanded to include the CDC Emerging Drug Panel, other OTC and prescription-abused drugs, plus additional fentanyl analogs and synthetic cannabinoids.
DBS reporting cutoffs were set based on the blood levels reported for therapeutic use (or typical forensic cutoffs when there is no therapeutic data). Urine cutoffs were typical levels used in clinical diagnostic testing (generally lower than forensic cutoffs).
Paired DBS and urine samples were collected from 1,113 donors at 60 community corrections locations (no more than 20 donors per location).
The most notable differences were methamphetamine and alcohol biomarkers. There were 232 DBS methamphetamine positives compared to 107 urine positives (50 ng/mL cutoff). Ethanol exposure was determined in DBS using 16:0/18:1 phosphatidylethanol (PEth) and ethylglucuronide/ethylsulfate (ETG/ETS) in urine. There were 187 DBS PEth positives, compared to 50 urine ETG/ETS positives.
Presenter: Kenneth Lewis (Owner, OpAns LLC)
Kenneth C. Lewis is the CEO of OpAns. OpAns provides high complexity analytical testing supporting Clinical Diagnostics, Forensic Toxicology, Clinical Trials, GLP pre-Clinical Toxicology, and its investigative lab servicing pharmaceutical discovery. OpAns specializes in multianalyte analysis from small volumes of biological samples.
Dr. Lewis earned his Ph.D. in Analytical Chemistry from the University of North Carolina at Chapel Hill under the direction of Jim Jorgenson. After a post-doctoral fellowship at Affymax Research Institute in Santa Clara, CA he joined the GlaxoWellcome discovery analytical group. In 2000 he accepted a position with Eli Lilly/Sphinx Labs where he was promoted to Research Advisor. In 2004 he left Eli Lilly to start OpAns.
