Institute of Chemistry, Karl-Franzens University Graz, 8010 Graz, Austria.
Environ Sci Technol. 2010 Feb 15;44(4):1478-83. doi: 10.1021/es9030358.
Arsenic occurs naturally in many types of seafood as water- and fat-soluble organoarsenic compounds. Although water-soluble compounds have been well characterized, the fat-soluble compounds, so-called arsenolipids, have until recently remained unknown. We report that sashimi-grade tuna fish, with a total arsenic content of 5.9 microg of As/g dry mass, contains approximately equal quantities of water- and fat-soluble arsenic. The water-soluble arsenic comprised predominantly arsenobetaine (>95%) with a trace of dimethylarsinate. Two fat-soluble compounds, which together accounted for about 40% of the lipid-arsenic, were isolated and characterized. The first was identified as 1-dimethylarsinoylpentadecane [(CH(3))(2)As(O)(CH(2))(14)CH(3)] by comparison of HPLC/mass spectrometric data and accurate mass data with those of an authenticated synthesized standard. The second arsenolipid was postulated as 1-dimethylarsinoyl all-cis-4,7,10,13,16,19-docosahexane from mass spectrometric data and analogy with non-arsenic-containing lipids found in fish. The remaining fat-soluble arsenic consisted of less polar arsenolipids of currently unknown structure. This is the first identification of arsenolipids in commonly consumed seafood.
砷以水相和脂溶性有机砷化合物的形式自然存在于多种类型的海鲜中。尽管水溶性化合物已得到很好的描述，但脂溶性化合物，即所谓的砷脂，直到最近才被发现。我们报告说，生鱼片级金枪鱼的总砷含量为 5.9 微克/克干重，其中含有等量的水溶性和脂溶性砷。水溶性砷主要由砷甜菜碱（>95%）和痕量二甲砷酸组成。分离并鉴定了两种共占脂质砷约 40%的脂溶性化合物。第一种通过比较高效液相色谱/质谱数据和准确质量数据与已认证合成标准品的数据，被鉴定为 1-二甲基砷酰基十五烷[(CH3)2As（O）（CH2）14CH3]。第二种砷脂是根据质谱数据和与鱼类中发现的非砷脂类物质的类比，推测为 1-二甲基砷酰基全顺-4,7,10,13,16,19-二十二烷。其余的脂溶性砷由目前结构未知的极性较小的砷脂组成。这是首次在常见的食用海鲜中鉴定出砷脂。
