我国马尾藻中砷的化学形态及其季节变化

CHEMICAL SPECIES AND SEASONAL VARIATIONS OF ARSENIC IN CHINESE SARGASSUM SAMPLES

于1996年3－8月在广东、广西及青岛沿海采集了部分代表性马尾藻，采用银盐分光光度法对新鲜样品中砷的化学形态、季节变化进行了研究。结果表明，广东、广西沿海马尾藻的总砷和无机砷含量较高，其中羊栖菜的无机砷含量占其总砷的56．73％，说明马尾藻富集无机砷的能力较强。青岛沿海鼠尾藻和海黍子的总砷含量在生长初期最低，成熟期增至最高，无机砷占总砷的比例也表现出类似的季节变化，说明藻体砷含量与其生长周期有密切联系。

Samples of Chinese Sargassum spp. were collected bo the coast areas ol Guangdong, Guangxi and Qingdao from Mar. to Aug. 1996. The samples were analysed using silver salt spectroscopy, a simple, accurate method in arsenic analysis. The results show that Sargassum spp. from the Guandong and Guanxi coast areas have high total and inorganic arsenic levels. Commonly, they contain more than 10.0×10-6 in fresh weight of total arsenic and above 20% of the percentage of inorganic arsenic in the total. Total arsenic contents of Sargassum hemiPhyllum are the highest, reaching 57.6×10-6 in fresh weighL For Xirgassum fusiforme, the percentage of inorganic arsenic in total arsenic reaches 56.73%. These observations suggest that the members of the Sargassaseae family can enrich the inorganic species of arsenic. Arsenic contents of Sargassum spp. from the Qingdao coast areas show cleary seasonal variations, with the lowest values at the young stage and the highest at maturity. The percentages of inorganic in total arsenic show similar curves of variations.Hence, areenic contents in Sargassum sPP. are closely relared to their growth cycle. In this paper, the contents, distribution pattems, seasonal variation and chemical species of arsenic, which is a representative toxic element, in Chinese Sargassum sPP. are studied. Accowrding to researches undertakn elsewhere, most of arsenic in seaweeds exists in the form of organic arsenic species, except for Sargassum sPP.This species contains more inorganic arsenic than the other seaweeds. The results of this paper show that the contents of areenic in canese Xirgasum sPP. Are similar to the results of the previous inveshgations. ms researeh on seaweed toxic elements chemistry is undertaken for the first time in China it will Play an important role in using the resources of Chinese Sargassum and developing the seaweed industry.