Analysis of Fish Sample with ICP-AES for Trace Element Contamination

Importance of the topic

Fish is a key dietary source of protein, essential fatty acids and minerals. However, industrial pollution can introduce toxic metals such as arsenic, cadmium and lead into aquatic environments. Routine monitoring of these trace elements in seafood is vital for consumer safety, regulatory compliance and environmental protection.

Objectives and Overview

This study evaluates the performance of an inductively coupled plasma atomic emission spectrometer for simultaneous quantification of nine trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, Zn) in fish. Using certified reference materials, the method is assessed for accuracy, precision and detection capability.

Methodology

Fish protein reference material (DORM-4) was subjected to microwave-assisted digestion with concentrated nitric acid and hydrogen peroxide in accordance with AOAC 999.10. The digested solution was diluted to a fixed volume, and calibration standards were matrix-matched using ICP multi-element and AAS stock solutions. Duplicate preparations ensured method reproducibility.

Instrumentation

• Shimadzu ICPE-9000 simultaneous ICP-AES
• Radio frequency power: 1.20 kW
• Plasma gas flow: 10.0 L/min; Auxiliary gas: 0.60 L/min; Nebulizer gas: 0.70 L/min
• Coaxial nebulizer with cyclone spray chamber and mini-torch
• Axial observation mode

Main Results and Discussion

Calibration curves for all targets showed excellent linearity (correlation coefficients > 0.9998). Detection limits ranged from 0.0005 to 0.032 ppm, with quantification limits below 0.11 ppm. Quantitation of DORM-4 closely matched certified values:

• As: 7.07 vs. 6.80 mg/kg; Cd: 0.312 vs. 0.306 mg/kg
• Cr: 1.74 vs. 1.87 mg/kg; Pb: 0.392 vs. 0.416 mg/kg
• Other elements showed comparable agreement within uncertainty limits.

Recovery assessment using CRM-TMF yielded 93 % to 106 % across analytes, confirming method accuracy and matrix robustness.

Benefits and Practical Applications

• Simultaneous multi-element analysis boosts sample throughput.
• Low detection limits enable trace-level surveillance in seafood and environmental monitoring.
• Matrix-matched calibration and certified reference materials ensure data reliability for regulatory and quality-control laboratories.

Future Trends and Potential Applications

Emerging enhancements in ICP-AES sensitivity, plasma control and detector technology will push detection limits lower and improve precision. Integration with automated sample preparation and chemometric modeling will streamline workflows for complex food and environmental matrices.

Conclusion

The presented ICP-AES approach delivers a rapid, precise and accurate solution for simultaneous determination of critical trace metals in fish. Agreement with certified values and high recoveries demonstrate its suitability for routine monitoring in food safety, research and industrial quality assurance.

References

1. AOAC Official Method 999.10: Mineral Content of Seafood by ICP-AES.