Automatic In-Syringe Dispersive Microsolid Phase Extraction Using Magnetic Metal-Organic Frameworks.

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Sample preparation is crucial for accurate chemical analysis.
• Dispersive micro-solid phase extraction (D-μ-SPE) offers advantages but often requires manual handling of micro/nanomaterials.
• Developing automated methods for D-μ-SPE is essential for high-throughput analysis.

Purpose of the Study:

• To report a novel automatic strategy for using micro- and nanomaterials as sorbents for D-μ-SPE.
• To demonstrate the first-time implementation of magnetic metal-organic framework (MOF) materials in automatic solid-phase extraction.
• To develop a safe and efficient automated sample preparation technique.

Main Methods:

• A hybrid magnetic metal-organic framework (MOF) material containing Fe3O4 nanoparticles was synthesized.
• The MOF material was immobilized on a miniature magnetic bar within a syringe pump system.
• Automatic dispersion and magnetic retrieval of the MOF sorbent were achieved using an automated magnetic stirring system.

Main Results:

• The method achieved a limit of detection of 0.012 mg/L for malachite green (MG) with a linear working range of 0.04-2 mg/L.
• An enrichment factor of 120 was obtained for MG preconcentration up to 40 mL sample volume.
• High recoveries (95-107%) were achieved for MG in water and fish samples, with an analysis throughput of 18 h⁻¹.

Conclusions:

• The developed automatic D-μ-SPE technique provides a safe and efficient alternative for sample preparation using small-sized materials.
• This lab-in-syringe approach is readily adaptable to other magnetic materials and easily hyphenated with various detectors.
• The automation significantly enhances analysis throughput and material reusability (up to 3000 extractions/g).