Toward a comprehensive study for multielemental quantitative LA-ICP MS bioimaging in soft tissues

Area of Science:

• Analytical Chemistry
• Bioimaging
• Toxicology

Background:

• Quantitative metal localization in tissues is crucial for understanding metal toxicity and biological roles.
• Existing methods may lack the sensitivity or scope for simultaneous multi-elemental analysis.

Purpose of the Study:

• To develop and validate a quantitative laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) bioimaging methodology.
• To enable simultaneous mapping of multiple metal elements in biological tissue sections using a polymer film strategy and internal standardization.

Main Methods:

• Development of a quantitative LA-ICP-MS bioimaging method utilizing a polymer film strategy with dextran as a soluble polymer.
• Internal standardization with Indium (In), Rhodium (Rh), and Iridium (Ir) to correct for signal variations.
• Optimization of analytical conditions including ICP power, oxygen addition, laser fluency, and tissue section thickness.

Main Results:

• Successfully mapped eight out of eleven elements (Co, Ni, Cu, Zn, Se, Mo, Cd, Pt) with good linearity using metal-spiked polymer standards.
• Identified three groups of elements based on their analytical response, influenced by First Ionization Potential (FIP) and matrix effects.
• Achieved low limits of detection (LODs) in the range of 0.1-1 μg g⁻¹ for the mapped elements.
• Validated the method using spiked kidney homogenate, showing close agreement with ICP-MS after mineralization (5-29% bias).

Conclusions:

• The developed LA-ICP-MS methodology provides a robust and quantitative approach for multi-elemental bioimaging of metals in biological tissues.
• The polymer film strategy and internal standardization effectively address matrix effects and improve analytical accuracy.
• This technique is the first to enable simultaneous quantitative bioimaging of eight elements, offering significant potential for toxicological and biological research.