A Study of Nickel Content in Korean Foods

Han, Hee Jin; Lee, Bo Hyun; Park, Chun Wook; Lee, Cheol Heon; Kang, Yun Seo

Abstract

BACKGROUND
Nickel-sensitive patients may suffer from persistent dermatitis even if they avoid cutaneous contact with nickel-plated items. Therefore, an endogenous cause of nickel-induced dermatitis has been suggested. In Western countries, many studies suggested that reduction of dietary intake of nickel might benefit nickel-sensitive patients. OBJECT: We measured the nickel content of Korean foods, since a nickel-restricted diet is essential for nickel-sensitive patients. METHOD: We ground the food, then nitric acid, sulphuric acid, and fluoric acid were added to the ground foods to dissolve organic matter. We then measured nickel content in these samples using Inductive Coupled Plasma-Mass Spectrometry. RESULTS: A green tea bag contained 235.57mg Ni/kg, a black tea bag 62.79mg Ni/kg, chocolate 27.87mg Ni/kg, crisps 12.70mg Ni/kg, wheat flour 12.15mg Ni/kg, Welsh onion 0.026mg Ni/kg, garlic 0.016mg Ni/kg, milk 0.004 mg Ni/kg, egg 0.002mg Ni/kg, and salt 0.0mg Ni/kg. CONCLUSION: High nickel concentrations were found in green tea bag, chocolate, crisps, wheat flour, coffee bean, peanuts, and kimchi etc. On the other hand, rice, barley and spice had low content of nickel. Formulation of nickel-restricted diet using these results is expected to be helpful in the treatment of nickel-sensitive patients.