Category: Automation and High-Throughput Technologies

1066-B - Automated dispersive pipette extraction of catecholamines and metabolites in urine using LC-MS/MS

Monday, February 5, 2018
5:00 PM - 6:00 PM

The catecholamines – epinephrine, norepinephrine, and dopamine – are bioamines that play an integral role as neurotransmitters in the central and peripheral nervous system. Screening for catecholamines and their O-methylated metabolites, metanephrine and normetanephrine, is a widely accepted approach for diagnosis of catecholamine-secreting tumors, such as pheochromocytomas, neuroblastomas, and paragangliomas. Catecholamines are characterized by a monoamine-linked benzene ring with two vicinyl hydroxyl groups (catechol). Epinephrine is a secondary amine, while norepinephrine and dopamine are primary amines. Under neutral and alkaline conditions, the catechol group makes the catecholamines vulnerable to oxidation to the quinone species. Metanephrines lack a catechol group, having a methoxy group adjacent to the hydroxyl group, and are thus more stable. These compounds are highly polar and hydrophilic, with negative log D and log P values. These structural properties make sample preparation and analysis difficult. Here we propose a diphenylborinic acid (DPBA) complexation with styrene divinyl benzene prior to dispersive pipette extraction (DPX) in order to minimize oxidation and maximize analyte recoveries from urine. Following elution, the complexation is reversed and the solution is ready for LC-MS/MS analysis. Automation of the DPX extraction using the Hamilton Microlab® NIMBUS96 facilitates higher throughput by extraction of 96 samples in less than 15 minutes. The method described herein is highly reproducible and provides the necessary sensitivity for clinical applications.

Kevin WP. Miller

Scientific Leader - Forensics
Hamilton Company
Reno, NV

Kevin Miller is Market Segment Leader, Regulated Laboratories at Hamilton Robotics in Reno, NV, where he provides thought leadership towards automated solutions throughout all aspects of this focused market. After earning a PhD in Molecular Anthropology from the University of Cambridge, Dr. Miller actively engaged in promoting, researching, and furthering forensic science advances, and remains committed to this endeavor today. In addition to academic and instructive teaching experience including developing and directing the Professional Science Master’s Degree Program in Forensic Science at the California State University, Fresno, he led forensic scientists and crime scene investigators at federal, state and local levels of government while integrating new/emerging forensic technologies such as the first local DNA database to use probabilistic genotyping for mixture resolution, and early adoption of digital and cloud-based documentation/reporting. He developed patented software to automate forensic facial reconstruction, and served as Program Manager for a mtDNA population database for the FBI, and ultimately migrated this into CODIS database. Dr. Miller is actively involved in forensic and crime scene associations, and publishes, lectures, and testifies on a wide breadth of forensic issues across the globe.