An online field-assisted micro-solid-phase extraction device coupled with high-performance liquid chromatography for...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Food Safety

Background:

• Traditional methods for analyzing trace contaminants in complex matrices are often time-consuming and labor-intensive.
• The need for rapid, sensitive, and accurate analytical techniques is crucial for ensuring food safety and monitoring environmental pollutants.
• Online analytical methods offer advantages in terms of automation, reduced sample handling, and improved precision.

Purpose of the Study:

• To develop and validate a total online analytical system combining field-assisted extraction (FAE), micro-solid-phase extraction (μ-SPE), and high-performance liquid chromatography (HPLC).
• To systematically investigate the influence of ultrasound-microwave synergistic effects and other extraction parameters on the analytical performance.
• To assess the applicability of the developed online method for the determination of polycyclic aromatic hydrocarbons (PAHs) in food and tetracycline antibiotics (TCAs) in cosmetic samples.

Main Methods:

• A fully automated online device was designed, integrating FAE, μ-SPE using a monolithic column for online cleanup, and HPLC for separation and detection.
• Solid samples underwent pretreatment using synergistic ultrasound-microwave effects.
• Optimization of extraction parameters, including the interplay between ultrasound and microwave, was systematically performed.

Main Results:

• The online method achieved low detection limits for nine PAHs (0.075–0.30 μg/kg) and four TCAs (0.02–0.06 μg/kg).
• Accurate quantification was demonstrated with recoveries ranging from 71.5–119.7% for PAHs in food samples and 75.3–118.0% for TCAs in cosmetic samples.
• Relative standard deviations (RSDs) were consistently low, below 10.9% for PAHs and 8.2% for TCAs, indicating high precision.

Conclusions:

• The developed total online FAE-μ-SPE-HPLC method offers a simplified, precise, and accurate approach for trace analyte determination in solid and semi-solid matrices.
• This automated system significantly improves upon traditional offline methods by reducing operational complexity and enhancing analytical performance.
• The methodology holds potential for broader applications in trace analysis and for investigating field-assisted extraction mechanisms.