Analysis of Trace Elements in Table Salt Using ICPMS-2050

Importance of Trace Element Analysis in Table Salt

Accurate monitoring of trace metal contaminants in food products is critical for consumer safety and regulatory compliance. Table salt, due to its high mineral content, poses analytical challenges that require sensitive, stable, and robust techniques. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) meets these requirements by offering simultaneous multi-element detection at trace levels, helping laboratories satisfy Codex and FDA standards.

Objectives and Study Overview

This study evaluates the Shimadzu ICPMS-2050 equipped with a mini-torch for long-term, cost-effective analysis of toxic elements in table salt. Key aims include:

• Determining detection limits relative to Codex reference values
• Assessing accuracy via spike recovery tests
• Evaluating instrument stability over extended runs

Methodology and Instrumentation

Sample Preparation:

• Unspiked and spiked salt solutions (0.4% w/v) digested with 5% v/v HNO₃ and 0.5% v/v HCl
• Method blanks prepared with acids only

Calibration and Quality Control:

• Four calibration standards covering 0–100 µg/L for major and trace metals
• Internal standard solution (Sc, Ge, Rh, Ir, Bi at 2 mg/L)
• Initial and continuing calibration verification (ICV, CCV) and blanks to ensure ongoing accuracy

Instrumentation:

• ICPMS-2050 with mini-torch (reduced Ar consumption)
• Nebulizer DC04, cyclone spray chamber, Ni sampling and skimmer cones
• AS-20 autosampler and online internal standard kit
• Operating conditions: 1.2 kW RF power, 9.0 L/min plasma gas, He/H₂ cell gas

Key Results and Discussion

Detection Limits and Sensitivity:

• Instrument detection limits ranged from 0.008 to 0.2 µg/L, an order of magnitude below Codex limits

Spike Recovery:

• Recoveries between 95% and 106% for all elements, indicating minimal matrix bias

Long-Term Stability:

• Signal drift of internal standards remained within 60–120% over 10 hours
• ICV and CCV recoveries stayed within 90–110%, meeting FDA EAM criteria

Benefits and Practical Applications

The ICPMS-2050 with mini-torch offers:

• High sensitivity for toxic metals in complex matrices
• Consistent accuracy across extended sequences
• Reduced argon consumption and operating costs
• Pre-configured methods to streamline setup and minimize method development

Future Trends and Applications

Advances in ICP-MS technology will focus on further reducing gas usage, enhancing interface robustness against high-matrix samples, and integrating automated data processing. Emerging collision/reaction cell chemistries and enhanced software tools are likely to expand applications in food safety, environmental monitoring, and clinical analysis.

Conclusion

The Shimadzu ICPMS-2050 demonstrates reliable, high-throughput quantification of trace elements in table salt, meeting international regulatory requirements. Its stable performance, cost-effective operation, and user-friendly presets make it a strong candidate for routine food safety testing.

References

1. Codex Alimentarius Commission. Codex General Standard for Contaminants and Toxins in Food and Feed (CODEX STAN 193-1995).
2. U.S. Food and Drug Administration. Elemental Analysis Manual Section 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).
3. U.S. Food and Drug Administration. Elemental Analysis Manual Section 3.2: Terminology, Version 3.0 (December 2021).