Accumulation of arsenic and calcium during the growth of Hijiki plants.

Abstract

In an attempt to study the accumulation processes of nutritionally important as well as ecologically unavoidable minerals in growing Hijiki (Sargassum fusiforme (Harvey) Setchell ** ) plants, tissue concentrations of calcium and arsenic were determined. Hijiki plants were harvested in several stages of their growth from November through April. Fresh plants were washed thoroughly and cut at a length of 10 cm along the stalk from the bottom to the top of the plants. The leaves and stalks were separated, weighed and stored at -40°C until freeze-dried. Arsenic was determined by HPLC-ICP-MS analysis after extraction of the samples with a HNO₃ solution, and calcium was determined by atomic absorption spectrophotometry in a 1M HCl solution containing strontium chloride, after ashing the samples with a mixture of conc. H₂SO₄-conc. HNO₃ on an electric furnace. The distribution of arsenic concentrations showed a correlation with those of calcium during growth of Hijiki plants, in contrast to the correlations between arsenic and zinc, which correlated only in the earlier stages of growth, although these correlations were not so evident as found between manganese and zinc concentrations.

** Newly proposed taxonomic name of Hizikia fusiforme Okam.¹⁾