New Pharmaceutical and Food & Beverage Applications for SPME/HPLC

Importance of the Topic

Solid Phase Microextraction (SPME) coupled with High-Performance Liquid Chromatography (HPLC) offers a streamlined, solvent-free approach for preparing complex biological and food matrices. The technique minimizes sample handling, reduces analysis time, and enhances sensitivity when monitoring thermally labile or weakly volatile compounds, such as pharmaceuticals in serum and preservatives in foods and beverages.

Objectives and Study Overview

The article presents two key application areas for SPME/HPLC: monitoring tricyclic antidepressant drugs in serum and determining antioxidants and preservatives in food and beverage samples. By replacing conventional liquid-liquid and solid-phase extraction techniques, the study aims to demonstrate the feasibility, reproducibility, and analytical performance of immersion SPME directly coupled to HPLC.

Methodology and Instrumentation

The general sample preparation involves adding a protein-denaturing solvent (methanol) to serum or diluting food/beverage samples, followed by immersion of a 40 µm polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber. Extraction times ranged from 15 to 30 minutes under rapid stirring, with desorption directly into the HPLC mobile phase for 1–10 minutes. Columns used include SUPELCOSIL™ LC-PCN (25 cm × 4.6 mm, 5 µm) and SUPELCOSIL LC-18 (15 cm × 4.6 mm, 3–5 µm). Mobile phases varied by application but typically combined acetonitrile, methanol, and buffered aqueous phases at flow rates of 1.5–2 mL/min and UV detection at 215–280 nm.

Main Results and Discussion

• Tricyclic Antidepressants in Serum: Three drugs (desipramine, nordoxepin, nortriptyline) achieved consistent recoveries, with response factor RSDs below 10% across eight extractions. Protein denaturation by methanol improved release of bound drugs, and immersion SPME ensured reproducible uptake and efficient transfer to the HPLC column.
• Antioxidants in Foods: Extraction of BHA and BHT from olive oil and soft drink powder provided clear chromatographic peaks with no interference from matrix components, eliminating extensive solvent extraction steps.
• Preservatives in Beverages: Simultaneous extraction of benzoic acid and caffeine from diet cola demonstrated that SPME/HPLC could replace multistep derivatization and concentration protocols while delivering rapid (<30 min) and sensitive analysis.

Benefits and Practical Applications

• Significant reduction in solvent consumption and disposal costs.
• Shortened sample preparation time compared with traditional methods.
• Enhanced sensitivity and selectivity for heat-sensitive or weakly volatile analytes.
• Versatility across pharmaceutical, environmental, and food quality control laboratories.

Future Trends and Potential Applications

Advancements in fiber coating chemistries and integration with automated sampling platforms will expand the range of target analytes. Coupling SPME/HPLC with mass spectrometric detection will further improve limits of detection and identification confidence. Emerging uses include in situ monitoring of environmental pollutants, therapeutic drug monitoring with minimal invasiveness, and rapid screening of food contaminants in production lines.

Conclusion

The integration of SPME with HPLC presents a robust, efficient alternative to conventional extraction techniques for a variety of analytes in complex matrices. The demonstrated applications in serum and food/beverage analysis highlight the method’s reproducibility, sensitivity, and operational simplicity, making it a valuable tool in analytical chemistry workflows.

Reference

• Product Specification 496049: HPLC/SPME interface details.
• Supelco Bulletin 901: Headspace SPME/GC applications for antidepressants.
• AOAC Official Method 983.15: Analysis of BHA and BHT in oils and fats.
• AOAC Official Method 983.16: Determination of benzoic acid in food matrices.