Evaluating LA-ICP-MS and digestion-based ICP-MS methods for trace elements determination in oil shale and its solid...

Area of Science:

• Analytical Chemistry
• Geochemistry
• Environmental Science

Background:

• Quantifying trace elements in complex matrices like oil shale and its solid wastes is analytically challenging.
• Accurate elemental analysis is crucial for resource recovery and environmental risk assessment in the oil shale industry.

Purpose of the Study:

• To compare the performance of seven analytical methods for quantifying 19 trace elements in oil shale and solid wastes.
• To identify the most effective method for mitigating matrix effects and achieving accurate trace element quantification.

Main Methods:

• Evaluated matrix-matched and matrix-independent laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).
• Assessed traditional solution-based inductively coupled plasma mass spectrometry (ICP-MS) with three different digestion protocols.
• Validated methods using certified reference materials and practical oil shale samples.

Main Results:

• Matrix-matched LA-ICP-MS using a lithium borate glass standard demonstrated superior analytical performance, effectively mitigating matrix effects.
• This method achieved high accuracy (recoveries within ±15%) and precision (coefficient of variation ≤5%) for most elements.
• Conventional ICP-MS methods showed limitations in accuracy and consistency for certain elements, particularly in complex ash matrices.

Conclusions:

• Matrix-matched LA-ICP-MS is a promising tool for rapid and accurate trace element quantification in oil shale and its solid wastes.
• The findings highlight the strengths and limitations of various analytical techniques for complex geological materials.
• This research supports improved resource recovery and environmental risk assessment in the oil shale sector.