Rapid and Sensitive Analysis of Taurine in Human Serum and Beagle Plasma using Liquid Chromatography-Tandem Mass Spectrometry

Importance of the Topic

Taurine is an aminosulfonic acid widely used in nutritional supplements, clinical formulations and research studies. Accurate and sensitive quantification in biological fluids such as human serum and animal plasma is critical for pharmacokinetic assessments, nutritional monitoring and preclinical studies. The development of a robust LC-MS/MS method addresses challenges of sensitivity, specificity and minimal sample preparation, enabling reliable detection at low concentration levels.

Objectives and Study Overview

This work aimed to establish a rapid, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for direct determination of taurine in human serum and beagle dog plasma. Key objectives included:

• Optimizing chromatographic separation and mass spectrometric detection parameters.
• Evaluating assay performance metrics such as linearity, accuracy, precision and carryover.
• Applying the method to real unknown beagle plasma samples to demonstrate practical utility.

Methodology and Instrumentation

Sample preparation involved protein precipitation of serum or plasma with acetonitrile containing 0.1 % formic acid, centrifugation and dilution of the supernatant. The LC system was a Nexera UHPLC coupled to a Shimadzu LCMS-8050 triple quadrupole mass spectrometer operating in negative electrospray ionization (ESI-) mode.

Instrumental Setup

• Column: Pentafluorophenylpropyl (PFPP), 150 × 2.1 mm, 5 µm.
• Mobile Phase A: 0.03 % formic acid in water; B: 0.03 % formic acid in methanol.
• Flow rate: 0.3 mL/min; column oven: 25 °C.
• Injection volume: 0.5 µL (Method 1) or 1.0 µL (Method 2).
• Mass spectrometer settings: nebulizing gas 2 L/min, heating gas 10 L/min, interface temperature 300 °C, DL temperature 250 °C, heat block 400 °C, drying gas 10 L/min.
• MRM transitions: taurine m/z 124.9→79.9; internal standards: sulfanilic acid m/z 172.0→79.95 and aspartic acid m/z 132.1→88.

Results and Discussion

The method exhibited excellent linearity over 0.025–50 µg/mL in serum and 0.5–60 µg/mL in beagle plasma (r>0.999). Accuracy for low, mid and high QC levels ranged from 95.2 to 98.8 % in serum and 97.6 to 103.4 % in plasma when using aspartic acid as the internal standard. Precision was demonstrated by standard deviations below 1.2 µg/mL across 12 unknown beagle plasma samples. No carryover was observed. Representative MRM chromatograms confirmed chromatographic resolution and signal specificity at low concentration levels.

Benefits and Practical Applications

• The assay requires minimal sample cleanup, reducing analysis time and labor.
• High sensitivity and specificity support low-level quantification in clinical and preclinical studies.
• Robust performance in different biological matrices enables cross-study comparability.
• Adaptable internal standard selection mitigates matrix effects across species.

Future Trends and Applications

Advances may include high-throughput multiplexed assays, microflow LC-MS/MS for reduced solvent consumption, and integration with automated sample preparation platforms. Emerging ambient ionization techniques and high-resolution mass spectrometry could further improve throughput and structural elucidation in complex biological matrices. Applications may extend to real-time monitoring of taurine kinetics in clinical trials and veterinary diagnostics.

Conclusion

A rapid, sensitive and accurate LC-MS/MS method for taurine quantification in human serum and beagle plasma was successfully developed and validated. The approach delivers excellent linearity, precision and accuracy with minimal sample preparation. Its application to unknown samples underscores its utility in pharmaceutical, nutritional and veterinary research.

References

1. Yu X, et al. Journal of Separation Science. 2016;36(18):3837–3844.
2. Chitranshi P, Gilles CT. Analysis of taurine in beagle plasma using LCMS-8050. SSI-LCMS-105 Application News.