Analysis of Arsenic in Canned Fish with Hydride Vapour Generation Method

Importance of the Topic

Accurate determination of arsenic in seafood is essential for ensuring food safety and regulatory compliance. Organic arsenic species predominate in marine samples, requiring effective sample decomposition and speciation control prior to analysis.

Objectives and Study Overview

This work evaluates hydride vapor generation coupled with flame atomic absorption spectrophotometry (AAS-HVG) and inductively coupled plasma atomic emission spectrometry (ICP-AES-HVG) for quantifying total arsenic in canned fish. Certified reference material was used to assess accuracy and precision.

Methodology and Instrumentation

Seafood samples underwent microwave-assisted nitric acid digestion followed by gentle heating to remove excess acid. Potassium iodide was added to reduce pentavalent arsenic to the trivalent state needed for hydride generation. Sodium borohydride in acid medium generated volatile arsenic hydride for introduction into the atomizer or plasma.

• ICP-AES: Shimadzu ICPE-9000 with mini-torch, axial observation, RF power 1.2 kW, plasma gas 10 L/min, auxiliary gas 0.6 L/min, nebulizer gas 0.8 L/min
• Flame AAS: Shimadzu AA-7000F, wavelength 193.7 nm, lamp current 12 mA, slit width 0.7 nm, deuterium background correction, air–acetylene flame
• Hydride generator: Shimadzu HVG-1, using sodium borohydride reagent and 1 M HCl carrier
• Sample digestion: Microwave system with nitric acid, water purification by reverse osmosis and electrodeionization

Main Results and Discussion

Calibration curves for both AAS-HVG and ICP-AES-HVG exhibited excellent linearity (r > 0.9999) over 0–10 ppb arsenic. Method detection limits were 0.1 ppb (3σ blank). Measured concentrations in FAPAS canned fish CRM (2550 µg/kg certified, range 1842–3259 µg/kg) were 2872 µg/kg (AAS-HVG) and 2709 µg/kg (ICP-AES-HVG), confirming method accuracy and reproducibility.

Benefits and Practical Applications

Hydride vapor generation enhances sensitivity and minimizes matrix interferences by converting arsenic to a volatile species. Both AAS and ICP-AES detection modes deliver reliable, low-level quantification of total arsenic in complex food matrices, supporting routine quality control in food safety laboratories.

Future Trends and Applications

Emerging developments include integration of hydride generation with ICP-MS for isotopic and speciation analysis, automation of sample digestion and reduction steps, online coupling of digestion–HVG systems, and tailored hydride protocols for individual arsenic species.

Conclusion

Hydride vapor generation combined with flame AAS or ICP-AES offers a robust, sensitive approach for total arsenic determination in canned fish. Key procedural steps—microwave digestion, acid removal, and pre-reduction—ensure complete conversion to the trivalent form and accurate recovery within certified reference ranges.

Reference

• AOAC Method No. 986.15: Arsenic, Cadmium, Lead, Selenium, and Zinc in Human and Pet Foods
• Shimadzu HVG-1 Instruction Manual
• Shimadzu AA Cookbook No. 3 – Flame AAS Parameters for Each Element
• ICPE-9000 Operation Training Material