Rapid Multidimensional GC Analysis of Trace Drugs in Complex Matrices


App Note 8/2007

Reduction in analysis time is an important goal for easing the burden of large sample sets associated with routine screening of blood samples and sample sets produced from drug metabolism studies. This study focuses on reduction in analysis time for simultaneous detection of delta-9-THC, 11-OH-THC, and THC-COOH in whole blood and urine extracts. This was achieved using the GERSTEL fast GC system combined with an Agilent GC-MSD. Addition of the fast GC system allows three independently heated temperature zones for multidimensional chromatography using Agilent Capillary Flow Technology Dean’s Switches along with fast heating/cooling rates. A novel pre-column approach protects the analytical columns in independent temperature zones and adds a high level of robustness. The Agilent Capillary Flow Technology Dean’s Switch allows a combination of heartcutting multidimensional GC and back flushing to reduce the amount of unwanted background components. Standard analysis time was reduced from 15 minutes to less than 11 minutes for blood samples and from 15 to less than 8 minutes for urine samples. Two Agilent Capillary Flow Technology Deans Switches in tandem were used for this analysis. Three independently programmed pressure zones were used in conjunction with three independent heated zones. The MS was operated in the EI mode.