Micro Ion Extractor for Single Drop Whole Blood Analysis.

Area of Science:

• Analytical Chemistry
• Biochemistry

Background:

• Iodide and thiocyanate are vital for thyroid hormone synthesis.
• Accurate quantification of these anions in blood is crucial for clinical diagnostics.
• Existing methods often require larger blood volumes and extensive sample pretreatment.

Purpose of the Study:

• To develop and validate a micro ion extractor (MIE) for direct trace anion determination in whole blood.
• To analyze iodide and thiocyanate levels using ion chromatography-mass spectrometry with minimal sample volume.
• To assess the feasibility of frequent, minimally invasive blood sampling for clinical studies.

Main Methods:

• A micro ion extractor (MIE) device was designed for 25 μL whole blood samples.
• Electromigration through a membrane transferred target anions to an acceptor solution.
• Online transfer of the acceptor solution to an ion chromatograph-mass spectrometry system for analysis.
• Optimization of isolator solution composition and applied voltage.

Main Results:

• The MIE device allowed reproducible determination of iodide and thiocyanate from a single drop of blood without pretreatment.
• Recoveries were consistent within ±10% relative standard deviation across diverse volunteers.
• Dietary effects on blood anion levels were successfully reported.
• The low sample requirement facilitated multiple sample collections per day.

Conclusions:

• The MIE device offers a highly sensitive and minimally invasive method for trace anion analysis in blood.
• This technology is suitable for clinical studies requiring frequent, small-volume blood sampling.
• The MIE system simplifies sample handling and reduces pretreatment steps for anion determination.