Analysis of Trace Elements in Certified Fish Sample with ICP-MS

Importance of the Topic

Fish constitutes a major component of the human diet due to its high protein content, low saturated fat levels and beneficial omega-3 fatty acids. However, environmental pollution can lead to accumulation of toxic metals such as arsenic, cadmium, lead, mercury and nickel in fish tissue. These contaminants pose serious health risks, including neurological disorders from mercury and carcinogenic effects of arsenic, making reliable monitoring essential for food safety.

Objectives and Study Overview

This application note describes the use of the Shimadzu ICPMS-2030 inductively coupled plasma mass spectrometer to perform simultaneous multi-element analysis of a certified fish protein reference material (DORM-4). The goals were to assess instrument sensitivity, spectral interference reduction via helium collision, and accuracy against certified values for trace metals in fish.

Methodology and Instrumentation

Sample Preparation

• Certified Reference Material DORM-4 (fish protein) from NRC Canada
• Microwave-assisted digestion of 0.5 g sample with 5 mL HNO3, 2 mL H2O2 and 1 mL water based on AOAC 999.10
• Final volume adjusted to 200 mL with ultrapure water

Instrumentation and Operating Conditions

• Shimadzu ICPMS-2030 with mini-torch to reduce argon consumption
• Helium collision gas to minimize polyatomic interferences (eg 40Ar16O on 56Fe)
• RF power 1.20 kW, plasma gas 8.0 L/min, auxiliary gas 1.10 L/min, nebulizer gas 0.60 L/min
• Coaxial nebulizer and cyclone spray chamber with electronic cooling

Calibration

• Multi-element standards for As, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Se, Zn
• Internal standards Bi, Ge, In, Sc at 10 ppb
• Acid-matched calibration ranges from 0–20 ppb for toxic elements to 0–2000 ppb for iron

Key Results and Discussion

Measured concentrations for all elements fell within the certified ranges of DORM-4, demonstrating method accuracy. Instrument detection limits (IDL) ranged from 0.001 ppb for Cd to 0.06 ppb for Fe, while limits of quantitation (LOQ) spanned 0.0044 ppb to 0.20 ppb. The helium collision system effectively suppressed common interferences, supporting reliable quantitation at trace levels.

Benefits and Practical Applications

The ICPMS-2030 offers:

• High sensitivity for multiple trace metals in a single run
• Reduced running costs via mini-torch argon savings
• Enhanced data quality through collision gas interference removal
• Rapid throughput suitable for routine food safety laboratories and QA/QC workflows

Future Trends and Opportunities

Advancements may include integration of automated sample preparation, further miniaturization of ICP-MS platforms for field deployment, enhanced software algorithms for spectral deconvolution, and coupling with chromatographic separation for speciation analysis. Increasing emphasis on real-time monitoring with sensor networks and AI-driven data analytics will drive broader adoption in environmental and food safety sectors.

Conclusion

The Shimadzu ICPMS-2030 demonstrates robust performance for simultaneous trace metal analysis in fish matrices. Excellent agreement with certified values, low detection limits and efficient interference suppression make it a powerful tool for ensuring seafood safety and regulatory compliance.

Reference

1. Sreenivasa Rao J, Vasudeva Rao Y, Devindra S, Longvah T Analysis of heavy metal concentrations in Indian marine fish using ICP-MS after closed vessel microwave digestion method International Journal of Analytical and Bioanalytical Chemistry 4(3): 67-73 2014
2. Emami Khansari F, Ghazi-Khansari M, Abdollahi M Heavy metals content of canned tuna fish Food Chemistry 93: 293-296 2005
3. Hachiya N The history and the present of Minamata disease Japan Medical Association Journal 49(3): 112-118 2006