LC/MS/MS Analysis for Drugs of Abuse Using Biocompatible Solid Phase Microextraction (BioSPME)

Paul Rodwell, Merck/Sigma-Aldrich Company Ltd, Cambridge, United Kingdom
Candace Price, Milliporesigma/supelco, Bellefonte, Pa, USA
Craig Aurand, Milliporesigma/supelco, Bellefonte, Pa, USA
Sara Smith, Milliporesigma/supelco, Bellefonte, Pa, USA
Emily Barrey, Milliporesigma/supelco, Bellefonte, Pa, USA
Klaus Buckendahl, Merck/sigma-aldrich Chemie Gmbh, Taufkirchen, Germany

The field of illicit drug testing has recently become a constantly changing environment with the rapid development of unregulated designer and synthetic compounds. These compounds are reported to generate stimulating affects similar to that of methamphetamine, heroin and MDMA. The difficulty for the forensic testing facilities is the fact these compounds are not detected under normal ELISA testing methods; additional more specific LC/MS methods are necessary. This study demonstrates the benefits of Biocompatible Solid Phase Micro Extraction (Bio-SPME) over “dilute and shoot” methods for the enrichment of illicit drugs directly from biological matrices in an effort to explore the utility and unique selectivity of these sampling devices.

In this study, a model set of drugs were utilized to compare the BioSPME sampling technique with “dilute and shoot” methods.  Samples are aliquoted into 96 well plates and extracted by immersion in the BioSPME fibers. The BioSPME fibers are then directly desorbed into solvent followed by direct LC/MS/MS quantitation.  Samples were also analyzed by direct dilution of the spiked matrix sample into appropriate solvents and analyzed by LC/MS/MS.

The BioSPME method enabled lower detection limits compared to the “dilute and shoot” preparation due to the ability to concentrate the analytes onto the fiber and desorb in minimal amounts of solvent.  In addition, significant reduction of the total MS background was observed for the BioSPME samples.  Matrix effects were significantly reduced for samples prepared with the BioSPME technique.  Loss of MS response was not observed for repeated analysis of the BioSPME extracts which caused less instrument cleaning and maintenance.  The combination of all of these benefits lead to a more rugged analytical method without sacrificing much in preparation time.