Quantification of Catecholamines and Metanephrines in Urine Using the Thermo Scientific™ TSQ Endura™ Mass Spectrometer for Research Use

Importance of the topic

Catecholamines and metanephrines play essential roles in neurotransmission and endocrine regulation. Accurate measurement in urine enables monitoring of adrenal function and detection of pheochromocytoma and related disorders.

Objectives and Study Overview

This study introduces a rapid LC-MS/MS method using simple liquid–liquid extraction to quantify adrenaline, noradrenaline, metanephrine, normetanephrine and dopamine in urine. Analytical validation covered sensitivity, linearity, accuracy, precision and matrix effects.

Methodology

The workflow comprises:

• Sample preparation via LLE using ethyl acetate and 2-aminoethyl diphenylboronate at pH 9.5 to complex cis-dihydroxyl groups.
• Internal standards (deuterated analogs) spiked into charcoal-stripped urine.
• Evaporation under nitrogen and reconstitution in mobile phase.
• LC separation on a 2.1×150 mm mixed-mode WCX column with a 10-min gradient (2 mM ammonium formate/0.1% formic acid and acetonitrile/0.1% formic acid) at 40°C.
• MS detection on a TSQ Endura triple quadrupole with heated electrospray ionization in positive mode, using scheduled SRM (two transitions per analyte, 0.5 min window).

Instrumentation Used

• Thermo Scientific UltiMate 3000 RS LC system
• Acclaim Mixed Mode WCX-1 column (2.1×150 mm, 3 µm)
• Thermo Scientific TSQ Endura triple quadrupole mass spectrometer
• Thermo Scientific TraceFinder 4.1 software

Main Results and Discussion

The method exhibited:

• Linearity from 0.4 to 900 ng/mL with correlation coefficients (R2) >0.9979.
• Lower limit of quantification at 0.4 ng/mL.
• Accuracy within ±15% (±20% at LLOQ).
• Intra-assay and inter-assay precision (%RSD) below 15% across concentration levels.
• Matrix effects ranging from ~85% to 130%, demonstrating acceptable signal suppression/enhancement.

Benefits and Practical Applications

Compared to SPE-based protocols, the LLE approach simplifies sample preparation, reduces processing time and cost, and preserves analytical performance. The method is well suited for research laboratories conducting neuroendocrine studies, toxicology and clinical biomarker discovery.

Future Trends and Opportunities

Advances may include automation of LLE, high-throughput sample processing, miniaturized workflows and expansion to multiplex panels for comprehensive catecholamine profiling. Integration with point-of-care platforms could further enhance clinical applicability.

Conclusion

A robust, validated LC-MS/MS procedure with simple LLE clean-up on a TSQ Endura instrument provides reliable quantification of urinary catecholamines and metanephrines, meeting research requirements for sensitivity, precision and accuracy.

References

• D. Talwar et al. J. Chromatogr. B 769 (2002) 341–349.