WCPS: Determination of Heavy Metals and Nutrient Elements in Alternative Protein Foods Using ICP-MS

Significance of the Topic

The rapid growth of alternative protein sources such as insect, fungal and plant-based materials presents new challenges for food safety and nutritional profiling. Monitoring both nutrient elements and toxic heavy metals is essential to ensure consumer health and regulatory compliance. Inductively coupled plasma mass spectrometry (ICP-MS) offers the sensitivity and multielement capability required to support Good Manufacturing Practices in the production of non-meat proteins.

Objectives and Study Overview

This study applied the US FDA Elemental Analysis Manual method EAM 4.7 to:

• Quantify 12 key elements in alternative protein food samples.
• Validate the accuracy and precision of an Agilent 7850 ICP-MS with collision cell in helium mode.
• Demonstrate applicability to insect powder, mushroom powder, almond meal and chickpea flour.

Methodology and Instrumentation

Sample Preparation

• Approximately 0.5 g of sample or certified reference material was digested in closed-vessel microwave system with 5 mL HNO3, 1 mL H2O2, then 0.5 mL HCl.
• Digests were diluted to 50 g with deionized water according to EAM 4.7 guidelines.

ICP-MS Analysis

• Instrument: Agilent 7850 ICP-MS equipped with an octopole reaction system (ORS4) and Ultra High Matrix Introduction (UHMI).
• Collision gas: helium in kinetic energy discrimination mode to reduce polyatomic interferences.
• Discrete sampling: ISIS accessory for high throughput and reduced sample waste.
• Half-mass correction implemented in MassHunter software to mitigate doubly charged interferences on As, Se and Zn.
• IntelliQuant quick scan provided semiquantitative screening for additional elements.

Main Results and Discussion

Validation with Certified Reference Materials

• Three CRMs (oyster tissue, dogfish liver, fish protein) showed recoveries of 80–120% for all certified elements, meeting FDA EAM 4.7 criteria.

Spike Recovery and Sample Analyses

• Spike recoveries in cricket protein, reishi mushroom, almond meal and chickpea flour fell within 80–120%, confirming method accuracy.
• Key nutrient elements (Na, Mg, P, K, Ca, Fe, Zn) and trace elements (Cr, Mn, Ni, Cu, As, Se, Mo, Cd, Hg, Tl, Pb) were quantified reliably.

IntelliQuant Findings

• Semiquantitative data revealed additional elements such as sulfur, strontium, iodine and rare earth elements in mushroom sample.
• Heat-map representation aided identification of potential interferences and compositional markers.

Benefits and Practical Applications

The described methodology delivers:

• High throughput multielement analysis with minimal matrix effects thanks to UHMI aerosol dilution.
• Accurate interference control via helium collision and half-mass correction without reactive gases.
• Reduced method setup time and maintenance frequency.
• Capability to screen unknown elements using IntelliQuant, supporting broader compositional studies.

Future Trends and Opportunities

As alternative proteins gain market share, future developments may include:

• Integration of real-time monitoring for inline quality control.
• Expansion of semiquantitative screening libraries to cover emerging contaminants and nutrient markers.
• Coupling ICP-MS data with molecular and isotopic techniques for product authentication and provenance studies.
• Automated workflows leveraging software-driven corrections to further simplify high-matrix sample analysis.

Conclusion

The Agilent 7850 ICP-MS method based on FDA EAM 4.7 provides a robust, precise and efficient workflow for the determination of heavy metals and nutrient elements in alternative protein foods. Validation with CRMs and spike recoveries confirms compliance with regulatory quality criteria, while advanced features like UHMI, helium collision mode and IntelliQuant extend analytical scope. This approach supports industry needs for food safety, nutritional labeling and quality assurance.

Used Instrumentation

• Agilent 7850 ICP-MS with ORS4 collision cell and kinetic energy discrimination.
• Ultra High Matrix Introduction system for high TDS samples.
• ISIS discrete sampling accessory.
• CEM MARS 6 closed-vessel microwave digestion system.

References

• US FDA Elemental Analysis Manual EAM 4.7 Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic, Cadmium, Chromium, Lead, Mercury and Other Elements in Food Using Microwave Assisted Digestion Version 1.2 February 2020