Analysis of a Toxicology Panel Using High-efficiency CORTECS Phenyl Columns

Importance of the Topic

Modern forensic toxicology demands rapid, reliable screening and quantification of diverse drug compounds. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) has become the method of choice for broad toxicology panels, yet column efficiency and selectivity remain critical to resolve structurally similar analytes in high-throughput workflows.

Objectives and Study Overview

This study evaluates the performance of a 1.6 µm CORTECS® Phenyl column for forensic toxicology applications. Two organic mobile phases, acetonitrile (ACN) and methanol (MeOH), were compared to illustrate selectivity differences and optimize separation of over 30 relevant drugs, including opioids, benzodiazepines, stimulants, and metabolites.

Methodology and Instrumentation

Methods were developed on an ACQUITY UPLC I-Class system coupled to a Xevo TQD mass spectrometer. A CORTECS UPLC Phenyl column (2.1×100 mm, 1.6 µm) was operated at 40 °C. Mobile phase A was water with 0.1 % formic acid; mobile phase B was either acetonitrile or methanol containing 0.1 % formic acid. Rapid gradients delivered full panels in under 4.5 minutes. Key performance metrics included retention time reproducibility, peak width, resolution, and baseline separation of isobaric compounds.

Instrument Used

• UPLC System: ACQUITY UPLC I-Class with Column Manager
• MS Detector: Xevo TQD triple quadrupole
• Column: CORTECS UPLC Phenyl, 1.6 µm, 2.1×100 mm

Main Results and Discussion

All 39 analytes eluted in under 4.5 minutes with high chromatographic efficiency (average peak widths of 2.41 s with ACN and 3.00 s with MeOH). Baseline resolution was achieved for critical isobaric pairs such as morphine/hydromorphone and methamphetamine/phentermine. Use of methanol enhanced π–π interactions with aromatic analytes, shifting retention and improving selectivity. For example, benzoylecgonine retention time increased substantially with MeOH, and the resolution between methamphetamine and phentermine improved from 1.88 to 4.85.

Benefits and Practical Applications

• High throughput: full panels in under 5 minutes
• Flexible selectivity: choice of organic phase tailors separation
• Robust resolution: baseline separation of structurally similar and isobaric compounds
• Broad applicability: consolidates multiple assays into a single run

Future Trends and Applications

Continued innovation in column chemistries and coupling with high-resolution mass spectrometry will further enhance forensic screening. Emerging trends include microflow UPLC to reduce solvent use, multimodal stationary phases for complementary retention mechanisms, and integration of automated sample preparation and AI-driven method optimization to accelerate throughput and data quality.

Conclusion

The 1.6 µm CORTECS Phenyl column delivers rapid, efficient, and highly selective separations for complex toxicology panels. By leveraging differential mobile phase interactions, laboratories can achieve robust baseline resolution of challenging analyte pairs in a single, high-throughput LC-MS/MS method.

References

• Webster L. The Role of Urine Drug Testing in Chronic Pain Management: 2013 Update. Pain Medicine News; 2013:45–50.