Development of a Mobile LC/MS Laboratory for On-Site Analysis of Breath Samples for THC.

Description:
Cannabis smokers have THC (tetrahydrocannabinol) present in the aerosol particles of exhaled breath samples after smoking. Breath samples were collected using the BreathExplor™ device. Each collected breath sample was extracted on a shaker with 150 uL ethanol solution containing 600 pg of internal standard, THC-d3, followed by centrifugation (5 min). The centrifugate solution was pipetted to micro autosampler vials for SIM LC/MS analysis using an Advion CMS compact mass spectrometer. Positive ion SIM LC/MS analyses under atmospheric pressure chemical ionization (APCI) conditions were used for analysis of the breath sample extracts. Calibrators prepared at six concentrations from 50 pg to 50,000 pg THC/sample using blank fortified breath samples showed a linear relationship for THC using the THC-d0/THC-d3 peak area ratio, with a coefficient of determination equal to R 2 > 0.99. The LLOQ was 50 pg/sample for SIM LC/MS and 10 pg for LC/MS/MS analyses. Authentic (positive) samples following cannabis smoking were obtained from a volunteer male and a female smoker. Twelve Exhaled breath samples were collected for each time point at zero-hour (prior to smoking), 30 min and at one hour time points from one through six hours post marijuana smoking. All post-smoking breath samples showed detectable THC concentrations ranging from 0.1 to 20 ng/sample. The 0-6-hour pharmacokinetic (PK) curves for each subject showed maximum THC levels at up to 20 ng/collector with a subsequent reduction of THC levels in breath through the six-hour time period. Confirmatory quantitative analyses were subsequently done with a reference LC-MS/MS method which mirrored the SIM LC/MS quantities of THC in the positive specimens. In development is the integration of a sophisticated robot with the SIM LC/MS system where the breath samples can be prepared robotically and analyzed by APCI SIM LC/MS in less than 10 minutes.

Speaker: Jack Henion - Cornell University
Professor Jack Henion is Emeritus Professor of Toxicology at Cornell University where he was a member of the College of Veterinary Medicine commencing in 1976. Dr. Henion was co-founder of Advion Biosciences in 1993 where he served as President and CEO until 2006 when he became CSO of Advion, Inc. Dr. Henion carried out a wide range of research in many application areas involving GC/MS and LC/MS/MS techniques. Professor Henion has received three Doctor Honoris Causa (Honorary Doctorate) degrees in recognition of his international reputation in modern analytical techniques. These were awarded from each of the University of Ghent, Uppsala University and Albany University. Professor Henion has published 235 peer-reviewed papers in the scientific literature, trained nearly 100 students, post-doctoral scientists, and trainees while receiving 12 patents for inventions developed from his work.