Quantification of steroids in human serum by TurboFlow online sample cleanup using a Transcend VTLX-1 UHPLC system

Importance of the Topic

Liquid chromatography–tandem mass spectrometry (LC-MS/MS) quantification of steroid hormones in human serum provides unparalleled specificity and sensitivity for clinical research and diagnostics. Implementing rapid online sample cleanup methods like TurboFlow streamlines workflows, reduces manual handling, and addresses laboratory space and budget constraints.

Study Objectives and Overview

The study compared analytical performance of a compact Transcend VTLX-1 UHPLC system against the existing Transcend TLX-1 front end, both coupled to a TSQ Altis triple quadrupole mass spectrometer. The method targeted eight steroids in human serum and evaluated chromatography, limits of quantification, accuracy, and intra-assay precision.

Methodology

• Offline protein precipitation of serum samples with methanol and concurrent addition of isotopically labeled internal standards.
• TurboFlow online cleanup on a Cyclone-P 0.5×50 mm column, followed by separation on an Accucore Biphenyl 50×2.1 mm, 2.6 µm analytical column.
• 5.0-minute UHPLC gradient using water and methanol with 0.2 mM ammonium fluoride.
• Detection by selected reaction monitoring (SRM) on a TSQ Altis mass spectrometer with HESI-II source in positive mode.

Used Instrumentation

• Transcend VTLX-1 and TLX-1 UHPLC systems
• Cyclone-P TurboFlow column (0.5×50 mm)
• Accucore Biphenyl analytical column (50×2.1 mm, 2.6 µm)
• Thermo Scientific TSQ Altis triple quadrupole mass spectrometer with HESI-II
• ClinMass Complete Kit for Steroids in Serum/Plasma (RECIPE Chemicals)

Main Results and Discussion

• VTLX-1 front end delivered notably sharper and more symmetric chromatographic peaks, particularly for early-eluting steroids.
• DHEAS was undetectable on TLX-1 due to delay volume; VTLX-1 produced a clear, symmetric peak.
• Linear calibration (1/x weighting) achieved R² ≥ 0.9995 on both systems.
• Accuracy bias remained within ±6.7% (TLX-1) and ±4.5% (VTLX-1); intra-assay precision CV < 2.3% for all analytes.

Benefits and Practical Applications

• Compact footprint and simplified sample preparation support space-limited laboratories.
• Five-minute turnaround for eight steroids enables high-throughput clinical testing.
• Optimized fluidics minimize dispersion and enhance signal intensity, improving method robustness.

Future Trends and Applications

Expanding TurboFlow cleanup to diverse analyte classes, integrating AI-driven method development, and further miniaturization of UHPLC platforms may enable decentralized and point-of-care steroid analysis.

Conclusion

The Transcend VTLX-1 UHPLC system matched or surpassed the TLX-1 in chromatographic quality, accuracy, and precision for steroid quantification in human serum, offering a rapid, reliable solution for modern clinical laboratories.

References

De Nardi C, Takarewski J. Quantification of steroids in human serum by TurboFlow online sample cleanup using a Transcend VTLX-1 UHPLC system. Thermo Fisher Scientific Technical Note 003505; 2025.