NEAFS: Synthetic fentanyl analogues and the new Agilent Ultivo Tandem Mass Spectrometer

Importance of the Topic

The ongoing opioid epidemic, driven by potent synthetic analogues such as fentanyls, poses significant public health risks. Accurate detection and quantification of these novel substances in biological specimens are crucial for forensic toxicology, clinical diagnostics, and regulatory monitoring.

Study Objectives and Overview

This work presents a rapid six-minute LC-MS/MS approach to simultaneously identify and quantify 12 emerging synthetic fentanyl analogues and the precursor 4-ANPP in serum and urine. The method evaluates performance on the compact Agilent Ultivo Tandem Mass Spectrometer, assessing its suitability for high-throughput forensic applications.

Methodology and Sample Preparation

• Urine: Negative human urine diluted 1/10 with water, centrifuged through 3 kDa filters, spiked with internal standards at 25 ng/mL, and serially diluted to prepare calibrators from 500 ng/mL to 1 pg/mL.
• Serum: Protein precipitation of serum with cold acetonitrile (1/3 ratio), centrifugation, spiking with internal standards at 50 ng/mL, dilution with water to achieve 25 ng/mL, and calibration series from 500 ng/mL to 1 pg/mL.
• Chromatography: Agilent 1290 UHPLC with Poroshell 120 EC-C18 (2.1×100 mm, 2.7 μm) at 55 °C, 5 μL injection, 0.5 mL/min gradient from 10 % to 95 % methanol/formic acid over 6 minutes.
• Mass Spectrometry: Agilent Ultivo TMS using positive AJS-ESI, optimized MRM transitions (38 transitions), unit resolution, 400 ms cycle time, and collision energies tailored per analyte.

Instrumentation Used

• Agilent 1290 Infinity II UHPLC: Binary pump, autosampler (6 °C), thermostatted column compartment.
• Agilent Ultivo Tandem Mass Spectrometer: AJS ESI source, VacShield source enclosure, Cyclone ion guide, vortex collision cell, hyperbolic quadrupoles, high-energy dynode detector.

Results and Discussion

• Sensitivity: LLOQs ranged from 10 to 100 pg/mL in urine and serum (equivalent to 60–1000 pg/mL pre-dilution).
• Linearity: Calibration from 1 pg/mL to 500 ng/mL with R²≥0.997.
• Precision: <10 % RSD at the LLOQ for all analytes.
• Specificity: Clear separation of isobaric compounds achieved within a 6-minute run time.
• Robustness: Compact instrument design enabled rapid ion injector changes, efficient maintenance, and stable performance.

Benefits and Practical Applications

• Rapid analysis and high throughput support timely forensic and clinical decision-making.
• Minimal sample preparation reduces labor and potential matrix effects.
• Compact footprint and intuitive maintenance features enhance laboratory efficiency.

Future Trends and Possibilities

• Expansion of analytical libraries to include emerging fentanyl analogues and cutting-edge illicit substances.
• Integration with automated sample preparation and data processing for higher throughput.
• Advancements in portable and miniature MS platforms for field and point-of-care testing.
• Adoption of high-resolution MS and ion mobility for even greater specificity and structural elucidation.

Conclusion

The described LC-MS/MS protocol on the Agilent Ultivo TMS delivers sensitive, precise, and rapid quantification of synthetic fentanyl analogues in biological matrices. Its streamlined workflow and robust performance underscore its value for forensic toxicology and emerging drug surveillance initiatives.

Reference

None provided.