Analysis of Heavy Metals in Baby FoodUsing ICP-MS

Significance of the topic

Analyzing toxic metal content in baby food is essential due to infants’ heightened vulnerability and stringent regulatory limits in the US and EU. Inductively coupled plasma mass spectrometry (ICP-MS) offers the sensitivity and multi-element capability needed to simultaneously quantify trace heavy metals in diverse food matrices.

Objectives and overview

This study evaluates the performance of the ICPMS-2040/2050 system for quantifying 13 regulated elements (As, Cd, Pb, Hg, Ni, Sn, and others) in five types of baby food (infant formula, rice cereal, strained corn, strained pumpkin/sweet potato, apple jelly). Key goals include method sensitivity, matrix interference mitigation, carryover prevention, spike recovery, and long-term stability assessment.

Used methodology and instrumentation

• Instrumentation: Shimadzu ICPMS-2040/2050 with AS-20 autosampler, mini-torch, DC04 nebulizer, cyclone chamber, nickel sampling/skimmer cones, and Online Internal Standard Kit (Ga, Te, Ir).
• Sample preparation: Approx. 0.5 g sample digested with HNO₃, H₂O₂, HCl in a microwave at 200 °C for 20 min, cooled and diluted to 25 mL (50× dilution). Method blanks prepared identically.
• Calibration and standards: Seven calibration levels covering key elements; internal standard solution at 200 µg/L with 20% IPA; ICV/CCV and blank verification samples per FDA EAM guidelines.
• Carryover control: LabSolutions ICPMS rinse function with two-step rinse (pure water and acid mix) plus Extended Rinsing and ProActive Rinsing features to minimize cross-contamination and reduce downtime.

Main results and discussion

Detection limits for all elements were below one-tenth of regulatory thresholds. Quantitative analysis across five baby food matrices demonstrated reliable detection: for example, Mn ranged from 379 to 9500 µg/kg, Zn from 90 to 74 500 µg/kg. Spike recovery tests yielded 88–110% across all elements and matrices, satisfying FDA EAM criteria. A long-term stability test on 50 infant formula samples over ~6 h showed internal standard signals within 60–120% and CCV recoveries within 90–110%, confirming robust calibration and minimal drift.

Benefits and practical uses

• Simultaneous multi-element detection with high sensitivity suitable for regulatory compliance.
• Effective matrix interference reduction via optimized digestion and cell gas conditions (He, H₂).
• Automated rinsing functions that significantly lower carryover and analysis turnaround time.
• Long-term measurement stability enabling high-throughput screening of baby food lots.

Future trends and possibilities

As ICP-MS technology evolves, expect further automation in sample handling and rinse protocols, enhanced collision/reaction cell chemistries for better interference removal, and expanded cloud-based QC dashboards. Advances in miniaturized torches, reduced gas consumption, and adaptation to new food matrices will broaden application scope in food safety labs.

Conclusion

The Shimadzu ICPMS-2040/2050 system provides rapid, sensitive, and stable multi-element analysis for baby foods. Coupled with robust sample preparation and intelligent rinsing strategies, it fulfills stringent regulatory requirements while minimizing carryover and downtime, making it a reliable tool for routine food safety testing.

Reference

1. US House of Representatives, The Baby Food Safety Act of 2021, accessed May 2021
2. Commission Regulation (EU) 2024/1987 of 30 July 2024 amending Regulation (EU) 2023/915 on nickel limits
3. Commission Regulation (EU) 2023/915 of 25 April 2023 on maximum levels for contaminants in food
4. U.S. FDA Elemental Analysis Manual 4.7, ICP-MS determination of heavy metals in food, Version 1.2 (Feb 2020)
5. U.S. FDA Elemental Analysis Manual 3.2 Terminology, Version 3.0 (Dec 2021)