Trace metals analysis in baby food using triple quadrupole inductively coupled plasma mass spectrometry (TQ-ICP-MS)

Importance of the topic

Ensuring the safety of baby food is critical because infants are highly susceptible to toxic elements such as arsenic, cadmium, lead and mercury. Regulatory bodies worldwide have established strict maximum levels for these contaminants. Reliable analytical workflows combining sensitive detection and robust sample preparation are essential to verify compliance and protect infant health.

Objectives and overview of the study

This work illustrates a complete workflow for quantifying toxic and nutritional trace elements in diverse baby food matrices. Key goals include demonstrating an automated digestion procedure, evaluating triple quadrupole ICP-MS performance, and comparing measured concentrations against legislative limits from The Baby Food Safety Act and EU guidelines.

Methodology and instrumentation

Samples covered wet products, dry powders and high-fat matrices. Main steps and equipment:

• Microwave-assisted acid digestion using ultraWAVE system (Milestone) for uniform sample breakdown
• Final dilution to 50 mL with ultra-pure water and direct introduction via iSC-65 autosampler
• Analysis on Thermo Scientific iCAP MTX TQ-ICP-MS operated in single-quad KED and triple-quad O2 modes to suppress polyatomic and isobaric interferences
• Automated internal standard addition (Sc, Ge, Rh, Ir) for matrix compensation
• Calibration with multi-element standards and low/high quality control checks for method validation

Main results and discussion

Analytical figures of merit demonstrated high sensitivity and accuracy:

• Correlation coefficients above 0.998 for all analytes
• Method quantification limits at least twice lower than regulatory thresholds for As, Cd, Hg, Pb
• Recoveries of toxic elements from certified reference materials between 90 and 120 percent
• Robust stability over eight-hour runs and across multiple days with consistent internal standard response

Comparison with regulatory limits revealed elevated total arsenic and mercury in some fish-based samples, highlighting the need for speciation studies to distinguish between inorganic and less toxic organic forms.

Benefits and practical applications

The combined microwave digestion and TQ-ICP-MS workflow delivers:

• High throughput and reproducibility across varied food matrices
• Simultaneous quantification of nutritional and toxic elements in a single run
• Automated interference management via collision/reaction gases
• Integrated software tools for simplified method setup and maintenance alerts

Future trends and opportunities

Possible developments to enhance baby food analysis include:

• Hyphenation with chromatographic separation for arsenic speciation
• Further automation and miniaturization of sample preparation
• Real-time data processing using machine learning for anomaly detection
• Portable ICP-MS systems for on-site screening in production facilities

Conclusion

This study confirms that microwave-assisted digestion combined with triple quadrupole ICP-MS provides a robust, sensitive and regulatory-compliant platform for comprehensive trace element analysis in baby foods. It supports routine monitoring, ensures consumer safety and can adapt to emerging regulatory and technological challenges.

References

• 1. Nóbrega JA, Carnaroglio D et al. Best practices in sample preparation of baby food for trace metal determination, Milestone Srl., 2022.
• 2. Sengupta S, Surekar B, Kutscher D. Application Note 000209 Using triple quadrupole ICP-MS for toxic and nutritional elements in baby foods, Thermo Fisher Scientific, 2021.
• 3. Raab A, McSheehy Ducos S. Application Note 43255 Determination of inorganic arsenic in rice using IC-ICP-MS, Thermo Fisher Scientific, 2018.