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 are critical biomarkers for assessing neurohormonal and adrenal function in clinical and research settings. Sensitive and reliable quantification in urine supports diagnosis of pheochromocytoma, neurological disorders and monitoring stress-related metabolic changes.

Objectives and Study Overview

This study aimed to develop and validate a rapid, high-throughput LC-MS/MS method for simultaneous measurement of adrenaline, noradrenaline, dopamine, metanephrine and normetanephrine in urine, using simple sample preparation and triple quadrupole detection.

Methodology and Instrumentation

• Sample preparation: liquid–liquid extraction with ethyl acetate and 2-aminoethyl diphenylboronate at pH 9.5 to complex cis-hydroxyl groups.
• Internal standards: deuterated analogues of each target analyte.
• Chromatography: Thermo Scientific UltiMate 3000 RS system, Acclaim Mixed Mode WCX-1 column (2.1×150 mm, 3 μm), 10-min gradient elution with 2 mM ammonium formate/0.1% formic acid and acetonitrile/0.1% formic acid.
• Mass spectrometry: Thermo Scientific TSQ Endura triple quadrupole, heated electrospray ionization in positive mode, scheduled SRM.

Main Results and Discussion

The assay exhibited linear calibration from 0.4 to 900 ng/mL (R² > 0.998) with LLOQ of 0.4 ng/mL. Accuracy bias was within ±15% for all levels and ±20% at LLOQ. Intra-assay RSDs ranged from 0.45% to 14.9%; inter-assay RSDs ranged from 2.17% to 14.55%. Matrix effects varied between 85% and 130% across analytes.

Benefits and Practical Applications

The streamlined LLE protocol eliminates complex SPE steps, reducing sample preparation time and cost. The validated method supports research applications in endocrinology, neuroscience and toxicology by providing robust quantification of catecholamines and their metabolites in urine.

Future Trends and Potential Applications

• Automation of extraction workflows with on-line or robotic liquid handling.
• Expansion to plasma and tissue matrices for broader clinical studies.
• Coupling with high-resolution mass spectrometry for untargeted metabolomics and profiling of related neurotransmitters.

Conclusion

This validated LC-MS/MS assay offers a sensitive, precise and efficient solution for quantifying catecholamines and metanephrines in urine, meeting research demands in biomedical and clinical investigations.

References

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