PDF(Pubmed)
Abstract：
Arsenic (As) species analysis is important for the risk evaluation of seafood. Until now, there has been limited information on the change of As species during digestion. Here, the As species in different types of seafood before and after in vitro digestion were investigated. Although inorganic As was not detected in digested fish samples, As(V) contents in digested crabs and scallops were 17.12 ± 1.76 and 138.69 ± 7.53, respectively, which were approximately 2-3 times greater than those of the pre-digestion samples. In further experiments, arsenocholine, dimethylarsinate, arsenobetaine, and monomethylarsonate were all convertible to As(V) during in vitro digestions with different rates. The transformation demonstrates a complex process and could be affected by many factors, such as pH, time, and digestion juice composition, of which pH seemed to be particularly important. Free radicals were responsible for the oxidation in the transformation reactions. Unlike arsenobetaine, arsenocholine seemed to be able to directly transform to monomethylarsonate without the intermediate dimethylarsinate. This study reveals and validates the potential of other species (oAs or/and unknown species) to convert to iAs, identifies the main factors affecting this process, and proposes a reaction pathway. There is an important implication for promoting a more accurate risk assessment of arsenic in foodstuffs.
摘要：
砷（As）物种分析对于海鲜的风险评估很重要。直到现在,关于消化过程中As物种变化的信息有限。这里,研究了体外消化前后不同类型海鲜中的As种。尽管在消化的鱼样品中没有检测到无机砷，消化蟹和扇贝中的As（V）含量分别为17.12±1.76和138.69±7.53，大约是消化前样品的2-3倍。在进一步的实验中,砷胆碱,二甲基氨酸盐,砷甜菜碱,单甲基arsonate在体外消化过程中以不同的速率转化为As（V）。这种转变表现出一个复杂的过程，可能受到许多因素的影响，如pH值,时间,和消化汁成分，其中pH值似乎特别重要。自由基是转化反应中氧化的原因。不像砷甜菜碱,砷胆碱似乎能够在没有中间体二甲基氨酸盐的情况下直接转化为单甲基氨酸盐。这项研究揭示并验证了其他物种（oAs或/和未知物种）转化为iAs的潜力，确定影响这一过程的主要因素，并提出了一种反应途径。对于促进更准确的食品中砷的风险评估具有重要意义。
