Determination of Beta Blockers from Urine Using SOLA CX and Accucore Core Enhanced Technology HPLC

Importance of Topic

Beta blockers are widely prescribed cardiovascular agents that require accurate monitoring in clinical and forensic laboratories. Efficient extraction and rapid analysis of these compounds from urine improve diagnostic reliability, sample throughput, and operational efficiency.

Study Objectives and Overview

This application note evaluates the performance of Thermo Scientific SOLA CX solid phase extraction cartridges coupled with Accucore Core Enhanced Technology HPLC for isolating and quantifying five beta blockers (atenolol, metoprolol, propranolol, alprenolol) and the internal standard pindolol from human urine.

Methodology and Instrumentation

• Sample Preparation: 800 µL urine samples were spiked with 100 µL pindolol internal standard (0.5 mg/mL) and 100 µL mixed primary standard (0.5 mg/mL).
• SPE Procedure: SOLA CX cartridges (10 mg/1 mL) were conditioned with 500 µL methanol and water, loaded with 200 µL spiked urine, washed sequentially with water/formic acid and methanol/formic acid, then eluted with dichloromethane/isopropanol containing 5% ammonia.
• Reconstitution: Dried extracts were reconstituted in 200 µL of 90:10 water:acetonitrile at temperatures below 40 °C.
• Chromatography: Thermo Scientific Accela 1250 system equipped with an Accucore C18 column (2.6 µm, 50 × 2.1 mm) operated at 45 °C. Mobile phases were water + 0.1% formic acid (A) and methanol + 0.1% formic acid (B), gradient from 10–40% B over 2.5 min, flow rate 0.7 mL/min, injection volume 1 µL, detection at 220 nm.

Results and Discussion

• Fast Separation: All five analytes eluted within three minutes, demonstrating suitability for high-throughput workflows.
• High Recoveries: Extraction recoveries exceeded 80% for each beta blocker, indicating efficient analyte retention and elution.
• Excellent Precision: Six replicate extractions yielded relative standard deviations between 3.2% and 4.4%, confirming method reproducibility.
• Reduced Solvent Usage: Lower elution volumes compared to conventional SPE reduce solvent consumption and analysis time.

Benefits and Practical Applications

• The method offers robust quantitation for clinical, forensic, and bioanalytical laboratories requiring reliable beta blocker measurement in urine.
• Lower solvent and sample volume demands decrease operational costs and environmental impact.
• Rapid chromatographic cycle times enhance laboratory throughput and efficiency.

Future Trends and Applications

• Coupling SOLA CX SPE with mass spectrometric detection to expand analyte coverage and specificity.
• Automating SPE workflows for higher throughput in regulated clinical diagnostics.
• Adapting SPE and rapid HPLC separations for a broader range of pharmaceutical and biomarker analyses.

Conclusion

The combination of SOLA CX cartridges and Accucore Core Enhanced Technology HPLC delivers a fast, precise, and solvent-efficient platform for beta blocker determination in urine, enhancing analytical confidence while reducing operational burden.