SPME-GCxGC-TOFMS Non-Derivatized Sample Analysis for Drugs in Urine

Significance of the Topic

Non-derivatized analysis of drugs in urine addresses the growing demand for rapid, selective, and sensitive toxicological screening in clinical, forensic, and occupational settings. SPME coupled with two-dimensional gas chromatography and time-of-flight mass spectrometry enhances separation power and detection without elaborate sample preparation.

Objectives and Study Overview

This application snapshot from LECO Corporation demonstrates the capability of SPME-GCxGC-TOFMS to identify six common drugs—methamphetamine, cocaine, codeine, diacetylmorphine, oxycodone, and alprazolam—in urine samples without derivatization.

Methodology

Solid-phase microextraction (SPME) was used for direct headspace sampling of non-derivatized urine. Two-dimensional gas chromatography employed a 30 m × 0.25 mm × 0.25 µm Rtx-5ms column in the first dimension and a 1.5 m × 0.18 mm × 0.18 µm Rtx-200 column in the second dimension, ensuring robust separation of structurally related compounds.

Used Instrumentation

• SPME sampling device
• GC×GC with Rtx-5ms (30 m × 0.25 mm × 0.25 µm) and Rtx-200 (1.5 m × 0.18 mm × 0.18 µm) columns
• Time-of-flight mass spectrometer (40–650 m/z, 200 spectra/s)

Main Results and Discussion

The method achieved clear, well-resolved chromatographic peaks for all six target compounds. High spectral acquisition rate enabled precise mass spectral identification, confirming positive detection of each drug in complex urine matrices without derivatization steps.

Benefits and Practical Applications

• No derivatization reduces sample preparation time and potential artifacts.
• Enhanced peak capacity from GC×GC improves resolution of co-eluting analytes.
• High-throughput screening suitable for forensic, clinical, and occupational monitoring.

Future Trends and Opportunities

Advances may include integration of automated SPME workflows, coupling with high-resolution mass analyzers for expanded compound libraries, and development of portable GC×GC-TOFMS platforms for on-site toxicology testing.

Conclusion

SPME-GCxGC-TOFMS offers a powerful, streamlined approach for non-derivatized urinary drug screening, delivering high sensitivity, selectivity, and throughput essential for modern analytical laboratories.

Reference

Form No. 209-200-060, LECO Corporation, 2008