Agilent Sample Prep, LC Columns, GC Columns, and Supplies Applications Compendium

Proven Approaches for Today’s Forensic Toxicology Challenges

Importance of the Topic

Rapid and defensible analytical methods are critical for forensic toxicology, workplace drug testing, post-mortem investigations, and legal proceedings. Reliable identification and quantification of drugs and metabolites directly impact public safety, workplace compliance, and the integrity of criminal investigations. The adoption of LC/MS/MS workflows that meet SAMHSA guidelines enhances throughput while reducing complexity compared to traditional GC/MS approaches.

Objectives and Overview of the Study

• Present a suite of simplified, SAMHSA-compliant LC/MS/MS methods for confirmation of six regulated drug classes in biological matrices.
• Demonstrate method performance metrics such as linearity, limit of detection, accuracy, precision, matrix effects, extraction recovery, and overall process efficiency.
• Showcase the use of Agilent Bond Elut Plexa PCX mixed-mode SPE, Agilent Poroshell 120 superficially porous LC columns, and Agilent Triple Quadrupole LC/MS systems with Jet Stream electrospray.

Methodology and Instrumentation

Sample Preparation and SPE

• Acidify 1 mL of matrix (urine, oral fluid) and spike with deuterated internal standards.
• Use Agilent Bond Elut Plexa PCX cartridges for mixed-mode retention of basic and hydrophobic analytes.
• Sequential washes (aqueous acid, organic solvents, hexane) to remove matrix interferences.
• Elute analytes with a basic organic mixture, evaporate to dryness, and reconstitute in initial LC mobile phase.

Chromatography and Mass Spectrometry

• Employ Agilent Poroshell 120 EC-C18 columns (3 × 50 mm, 2.7 µm) for rapid, high-efficiency separations under 400 bar.
• Use shallow, fast gradients (5–10% to 90% organic) to elute analytes in 2–6 minutes, diverting early and late eluent to waste.
• Detect analytes by MRM on Agilent 6460 or 6460A Triple Quadrupole LC/MS with Jet Stream technology, in positive or negative ion mode as required.
• Monitor one quantifier and at least one qualifier transition per analyte; enforce ion ratio criteria within ±20%.

Main Results and Discussion

• Linearity: R2 ≥ 0.998 over broad dynamic ranges (typically 10–400 ng/mL up to 20 000 ng/mL).
• Limits of Detection: Achieved S/N > 150–800 at 10% of SAMHSA cutoff levels (LODs as low as 0.5–2.5 ng/mL).
• Recovery: SPE recoveries of 83–97% for opiates, 85–96% for cannabinoids, and 94–97% for amphetamines.
• Matrix Effects: Minimal ion suppression/enhancement (±1–10%) due to Plexa’s hydroxylated polymer surface.
• Precision and Accuracy: Intra- and inter-day CVs < 2% at mid-levels; accuracies within ±10% of nominal.

Benefits and Practical Applications

• Elimination of derivatization steps and reduced sample preparation time.
• Compatibility with conventional 400 bar LC systems using superficially porous columns.
• High throughput: short run times, automated SPE, and minimal carryover.
• Legally defensible data sets for workplace, forensic, clinical, and QA/QC laboratories.

Future Trends and Opportunities

• Extension of workflows to emerging synthetic opioids, designer stimulants, and novel cannabinoids.
• Integration of automated SPE platforms and online SPE-LC/MS/MS coupling.
• Application of high-resolution mass spectrometry and multiplexed MRM for broad-scope screening.
• Development of point-of-care and field-deployable LC/MS interfaces for roadside and rapid forensic testing.

Conclusion

Agilent’s integrated approach—combining Bond Elut Plexa PCX SPE, Poroshell 120 columns, and Jet Stream-equipped triple quadrupole MS—delivers rapid, sensitive, and robust methods that comply with SAMHSA requirements. These workflows simplify forensic toxicology testing, reduce laboratory overhead, and generate high-confidence results suited for modern analytical demands.

Reference

• SAMHSA. Manual for Urine Laboratories, National Laboratory Certification Program (2010).
• Baselt, R. Disposition of Toxic Drugs and Chemicals in Man, 8th Ed. (2008).
• Matuszewski, B.K., Constanzer, M.L., Chavez-Eng, C.M. Anal. Chem. 75, 3019–3030 (2003).
• Moorman, P., Hughes, J. Agilent Application Notes for SAMHSA-Compliant LC/MS/MS Methods (2010–2013).