Comparison of Sample Preparation Methods for Multielements Analysis of Olive Oil by ICP-MS

Area of Science:

• Analytical Chemistry
• Food Chemistry
• Spectroscopy

Background:

• Elemental analysis of olive oil using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is hindered by high organic content and low analyte levels.
• Existing sample preparation methods for ICP-MS analysis of olive oil lack standardization, leading to variable results.

Purpose of the Study:

• To compare the efficacy of different inorganic element extraction methods for olive oil analysis via ICP-MS.
• To identify an optimal sample preparation technique that enhances detection limits and precision for olive oil analysis.

Main Methods:

• Evaluated three extraction techniques: microwave-assisted acid digestion, liquid-liquid ultrasound-assisted extraction, and a combined microwave digestion-evaporation method.
• Quantified inorganic elements in olive oil samples using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).

Main Results:

• Microwave digestion methods showed suboptimal performance.
• Ultrasound-assisted extraction demonstrated superior simplicity, lower detection limits (0.00061–1.5 µg·kg⁻¹), and better repeatability (5.1–40%).
• Combined digestion-evaporation yielded detection limits of 0.012–190 µg·kg⁻¹ and repeatability of 5.4–99%.

Conclusions:

• Ultrasound-assisted extraction is recommended for preparing olive oils for ICP-MS analysis.
• This method improves the detection of a wider range of elements, enhancing geographical traceability models for olive oil.