Advancing elemental analysis by collision/reaction cell technology and micro-droplet calibration for bioimaging applications by LA-ICP-TOFMS
Theiner et al.
분석 키미카 액타, 2024
DOI:10.1016/j.aca.2024.343345
In a recent publication in 분석 키미카 액타, researchers from the 비엔나 대학교 활용된 icpTOF 2R coupled to the Iridia laser ablation system from Teledyne Photon Machines in collision/reaction cell (CCT) mode. This setup enhances the quantification and sensitivity of both endogenous and higher mass range elements. It streamlines bioimaging applications and improves quality control through the integration of serum reference material.
Metal homeostasis is vital for cellular processes, and imbalances in metal levels can lead to diseases like dementia and cancer. To investigate these imbalances at a single-cell level, advanced analytical techniques like laser ablation inductively coupled plasma time-of-flight mass spectrometry (LA-ICP-TOFMS) are essential. Recent developments in LA systems allow for enhanced sensitivity, rapid acquisition speeds, and high spatial resolution, enabling precise elemental mapping.
However, quantifying metals in biological samples is challenging due to the complexity of sample matrices and the need for suitable calibration standards. Traditional methods have evolved towards automated production using biological matrix mimics, such as gelatin, which simplifies standard preparation. This study introduces a new calibration approach using gelatin micro-droplet standards and serum reference materials for accurate quantification of critical elements like iron, copper, and zinc. Additionally, the research compares standard and collision/reaction cell modes in LA-ICP-TOFMS, focusing on the simultaneous detection of lower and higher mass range elements. By optimizing operating parameters, the study was able to enhance sensitivity for various analytes, including metal-conjugated antibodies and nanoparticles, in biological applications.
The CCT mode (using a He/H2 gas mixture) in LA-ICP-TOFMS outperformed the standard mode for bioimaging, achieving accurate quantification of endogenous elements, particularly iron and selenium, from microdroplet standards. Sensitivity for higher mass range elements improved by 1.5 to 2.0 times, eliminating the need for complex post-data strategies. Integrating Seronorm serum reference material into workflows enhanced accuracy and quality control and analyzing three quality control samples only added five minutes to calibration time, with future one-point calibration approaches potentially further reducing calibration and quality control durations.
This study highlights the effectiveness of our cutting-edge icpTOF imaging technology for comprehensive elemental analysis across the entire mass range in bioimaging applications. The CCT mode significantly improves the quantification of endogenous elements like iron and selenium, with isotope ratios closely matching natural values, while also enhancing sensitivity for higher mass range elements. Integrating Seronorm serum reference material into LA-ICP-TOFMS workflows further streamlines quality control and validates measurements of key biological elements.
