Heavy metal analysis in commercial Spirulina products for human consumption

For consumption of health foods of Spirulina, by the general public, health food stores are increasingly offering more exotic products. Though Spirulina consumption is growing worldwide, relatively few studies have reported on the quantities of heavy metals/minerals they contain and/or their potential effects on the population's health. This study reveals the concentrations of six typical heavy metals/minerals (Ni, Zn, Hg, Pt, Mg, and Mn) in 25 Spirulina products commercialized worldwide for direct human consumption. Samples were ground, digested and quantified by Coupled Plasma Mass Spectroscopy (ICP-MS). The concentrations (mg/kg d.w.) were range from 0.001 to 0.012 (Pt) followed by 0.002-0.028 (Hg), 0.002-0.042 (Mg), 0.005-2.248 (Mn), 0.211-4.672 (Ni) and 0.533-6.225 (Zn). The inorganic elements of the present study were significantly lower than the recommended daily intake (RDI) level of heavy metal elements (mg/daily) Ni (0.4), Zn (13), Hg (0.01), Pt (0.002), Mg (400) and Mn (4). Based on this study the concentration of inorganic elements was not found to exceed the present regulation levels, and they can be considered as safe food.