HPLC-UV Method for the Determination of Procainamide from Human Plasma Using SOLA CX

Importance of the Topic

Procainamide is a commonly prescribed antiarrhythmic agent used to manage irregular heartbeats. Accurate quantification in human plasma is crucial for therapeutic drug monitoring, dosage optimization, and clinical research. Developing rapid, reliable analytical methods supports patient safety and enhances laboratory efficiency.

Study Objectives and Overview

This application note details the development of an HPLC-UV method for simultaneous determination of procainamide and its surrogate internal standard sulfanilamide in human plasma. The study compares Thermo Scientific SOLA CX solid-phase extraction (SPE) cartridges with conventional loose-packed SPE products, focusing on recovery, precision, solvent consumption, and analysis speed.

Methodology and Instrumentation

The sample preparation workflow includes:

• SOLA CX SPE: conditioning with methanol and water, application of 250 µL spiked plasma, two sequential washes (water/formic acid and methanol/formic acid), elution with methanol/ammonia, drying, and reconstitution in water.
• Loose-packed SPE: similar protocol scaled to 500 µL plasma and solvents.

Instrumentation

The analytical system comprises a Thermo Scientific HPLC equipped with a Syncronis C18 column (5 µm, 100 × 4.6 mm) and UV detection at 277 nm. The mobile phase uses 20 mM ammonium acetate (A) and methanol (B) in a gradient from 5 % to 95 % B over 5 minutes, at 1 mL/min and 30 °C. A 10 µL partial loop injection completes each analysis.

Main Results and Discussion

SOLA CX cartridges delivered mean recoveries of 119 % for procainamide and 77.8 % for sulfanilamide with RSDs of 4.0 % and 11.0 %, respectively. Conventional loose-packed SPE yielded 106 % and 97.3 % recoveries with RSDs up to 10.7 % and 21.0 %. Chromatographic separation of both analytes was achieved in under 5 minutes, demonstrating superior reproducibility, reduced solvent usage, and faster throughput with SOLA CX.

Practical Benefits and Applications

The optimized SPE-HPLC-UV method minimizes solvent consumption and sample preparation time while enhancing precision and reproducibility. It is particularly suited for high-throughput bioanalytical and clinical laboratories performing therapeutic drug monitoring and pharmacokinetic studies.

Future Trends and Opportunities

Emerging SPE sorbent technologies and miniaturized chromatographic systems will further streamline workflows. Coupling these approaches with mass spectrometry detection can improve sensitivity and multiplexing. Automation and integration into high-throughput platforms will continue to drive efficiency and reproducibility in clinical diagnostics.

Conclusion

The SOLA CX SPE protocol combined with Syncronis C18 HPLC-UV analysis offers a fast, reproducible, and solvent-efficient solution for quantifying procainamide and sulfanilamide in human plasma, outperforming traditional loose-packed SPE methods.