IMPROVING CHROMATOGRAPHIC PERFORMANCE FOR METAL SENSITIVE ANALYTES USING HYBRID SURFACE BARRIER TECHNOLOGY

Significance of the Topic

Metal-sensitive analytes such as phosphate-containing steroids can adhere to metal surfaces within liquid chromatography systems, leading to peak tailing, reduced sensitivity, and variable quantitation. Overcoming these challenges is critical for accurate bioanalysis in pharmaceutical research.

Objectives and Study Overview

This work evaluates the performance of a low-adsorption UHPLC system and sub-2 µm particle column featuring hybrid surface barrier technology (MaxPeak HPS) to improve chromatographic behavior of hydrocortisone phosphate and dexamethasone phosphate extracted from human plasma, comparing results against conventional UHPLC configurations.

Methodology and Instrumentation

Sample preparation involved protein precipitation of spiked human plasma followed by LC-MS/MS analysis. Calibration curves ranged from 5–1000 ng/mL (hydrocortisone phosphate) and 1–1000 ng/mL (dexamethasone phosphate). Chromatography was performed on a Waters ACQUITY Premier system with a Premier column (HPS surface) and compared to a conventional ACQUITY UPLC I-Class PLUS system with HSS T3 column. Detection employed a Waters Xevo TQ-XS tandem quadrupole mass spectrometer in ESI– mode. Mobile phases consisted of 0.1% formic acid in water (A) and acetonitrile (B) with a gradient from 5 to 75% B over 2.5 min at 0.6 mL/min, column temperature of 60 °C, and 10 µL injection volume.

Main Results and Discussion

Use of MaxPeak HPS technology resulted in markedly improved peak shapes, narrower peak widths, and enhanced sensitivity for both analytes. Representative chromatograms showed superior performance at 2.5 ng/mL concentrations. Calibration curves exhibited linearity with r2 ≥ 0.99, limits of detection and quantification between 1–2.5 ng/mL, and accuracy within 15%. Quality control samples demonstrated precision below 11% RSD.

Benefits and Practical Applications

Incorporation of hybrid surface barrier technology offers robust mitigation of non-specific adsorption, enabling reliable quantitative assays of metal-sensitive drugs in biological matrices. The approach reduces system conditioning requirements and avoids use of chelating mobile phase additives that may compromise MS response.

Future Trends and Potential Applications

• Extension of surface barrier chemistries to a broader range of metal-sensitive compounds
• Integration with high-throughput and automated workflows in drug development
• Development of next-generation low-adsorption columns for complex biological samples

Conclusion

The ACQUITY Premier system with MaxPeak HPS technology significantly enhances chromatographic performance and quantitative reliability for hydrocortisone phosphate and dexamethasone phosphate in plasma. This proof-of-concept demonstrates promise for improving bioanalytical assays in pharmaceutical research and quality control.

References

1. Hassn M. E. Dexamethasone in Severe COVID-19 Infection: A Case Series. Respiratory Medicine Case Reports. 2020, 31, 101205.
2. Cevc G, Blume G. Hydrocortisone and Dexamethasone in Deformable Drug Carriers: Increased Biological Potency and Prolonged Effect. Biochimica et Biophysica Acta – Biomembranes. 2004, 663(1–2):61–73.
3. Lauber M, et al. Low Adsorption HPLC Columns Based on MaxPeak High Performance Surfaces. Waters White Paper, 720006930EN, 2020.