Stirring-controlled solidified floating solid-liquid drop microextraction as a new solid phase-enhanced liquid-phase...

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Classical solidification of floating organic drop microextraction methods are often tedious and require disperser solvents.
• Limitations include time-consuming steps like centrifugation and incomplete solvent recovery.

Purpose of the Study:

• To develop a facile and efficient microextraction technique overcoming the limitations of existing methods.
• To introduce a stirring-controlled solidified floating solid-liquid drop microextraction (SC-SF-SLDME) utilizing a magnetic nanoadsorbent.

Main Methods:

• Preparation of magnetic carbon nanotube-nickel hybrid (MNi-CNT) via spray pyrolysis.
• Ultrasonic dispersion of MNi-CNT followed by high-rate stirring to disperse 1-undecanol (liquid phase).
• Formation of a solid-liquid drop upon reducing stirring speed, facilitating MNi-CNT and solvent droplet collection via hydrophobic forces.

Main Results:

• The MNi-CNT nanoadsorbent plays a crucial role in the extraction efficiency.
• Complete solvent collection is achieved with the solid phase, unlike methods without it.
• The method demonstrated short extraction times and effective dispersion of solid/liquid phases.
• Achieved low limits of quantification (LOQs) for imatinib, sunitinib, erlotinib, and nilotinib (0.6–1.7 μg L⁻¹).
• High intra-day precisions (RSDs < 4.5%) and good recoveries (93–98%) in human serum and cerebrospinal fluid.

Conclusions:

• SC-SF-SLDME is a highly efficient and rapid microextraction technique.
• The use of MNi-CNT as a magnetic nanoadsorbent significantly enhances extraction performance.
• The method is suitable for the sensitive determination of tyrosine kinase inhibitors in complex biological matrices.