Lead, cadmium, arsenic and mercury in canned tuna fish marketed in Tehran, Iran

Abstract

Fifty-four canned tuna fish samples corresponding to 10 widely used different brands were purchased from local markets in Tehran, Iran during 2012–2013 and analysed on heavy metals. Mercury was determined by a direct mercury analyser without any sample preparation. For analysis of other elements samples were digested using a microwave apparatus. Lead and cadmium were determined by graphite furnace atomic absorption spectrometry and arsenic via hydride vapour generation. All samples had arsenic and mercury contamination. Arsenic levels showed a range of 0.25−1.42 mg kg⁻¹, which might be due to lack of national and international limits for arsenic in canned tuna fish. Lead and cadmium were measured in a small number of samples with a mean of 0.053 ± 0.058 mg kg⁻¹ and 0.013 ± 0.015 mg kg⁻¹, respectively. Results obtained for these heavy metals in all samples were lower than the corresponding limits, whereas arsenic and mercury contents might raise some attention.

Keywords:

• heavy metals
• canned tuna fish
• microwave digestion
• hydride generation
• graphite furnace
• direct mercury analyser

Acknowledgements

The authors are grateful to the staff members of the Heavy Metals Analysis lab and Food Contaminants lab, FDLRC.

Additional information

Funding

This study was supported by the Food and Drug Laboratory Research Center (FDLRC), Ministry of Health and Medical Education of Iran.