我国几种重要经济贝类中砷的含量及其形态特征转化规律

Arsenic content and speciation analysis of several economic shellfishes in China

为了研究贝类中砷的含量及其形态特征,实验采用HPLC-ICP-MS联用技术结合体外全仿生消化模型分析了我国几种重要经济贝类中砷的形态特征及4种主要有毒砷形态的含量。结果显示,缢蛏中总砷含量最高,浓度为5.68 mg/kg,毛蚶4.83 mg/kg,栉孔扇贝、牡蛎和鲍鱼的含量为2.26～2.70 mg/kg,且三者之间无显著差异(P>0.05),菲律宾蛤仔和贻贝中总砷含量较低,分别为1.35和1.57 mg/kg。砷甜菜碱(AsB)是所有贝类水提液和胃肠全仿生消化液中砷的主要形态,尤其对于毛蚶,AsB是唯一的砷形态。栉孔扇贝、菲律宾蛤仔和缢蛏水提液中分别检测到0.025、0.008和0.300 mg/kg As3+,另外缢蛏水提液中还检测到0.115 mg/kgAs5+。除毛蚶和贻贝外,其余5种贝类的水提液中均检测到不同浓度的DMA,其中缢蛏中DMA浓度最高,为0.674 mg/kg。将贝类样品经过胃和肠消化液作用后,仅在缢蛏的肠消化液中检测出DMA,其余6种贝类中均未检出4种主要有毒砷形态。研究表明,贝类体内的砷形态及含量与在胃肠消化液作用后的砷形态及含量存在很大差异,尤其表现在4种主要有毒砷形态。

The arsenic speciation and the content of four toxic arsenic （including As3＋ , As5＋ , MMA and DMA）in several main economic shellfishes in our country were analyzed using HPLC-ICP-MS combined with in vitro digestion method. Results showed that S. strictus had the highest total arsenic content（5.68 mg/ kg） ,the second was in S. Subcrenata（ 4. 83 mg/kg） ,the total arsenic content in C. Farreri, C. Ostreae and H. discus hannai were much lower（2.26 -2.70 mg/kg）and three of them had no significant difference. The lowest content was in R. Philippinarum and M. edulis. AsB was the main arsenic speciation in both water extraction and gastrointestinal extraction for all samples, and especially for Scapharca subcrenata, AsB was the only arsenic speciation. About 0. 025,0. 008 and 0. 300 mg/kg As3＋ were separated in the water extraction of C. farreri,R, philippinarum and S. strictus respectively. In addition,0.115 mg/kg As5＋ was also detected in the water extraction of S. strictus. Different concentration of DMA was found in the water extraction of all samples except for S. subcrenata and M. edulis, with the highest content of 0. 674 mg/kg in S. strictus. However,except in S. strictus, DMA was detected in the intestinal extraction, none of four toxic arsenic speciations were found in the gastrointestinal extraction of other shellfishes. Present experiments proved that the arsenic speciation in the water extraction which could reflect the real content in shellfishes and in gastrointestinal extraction which could reflect the real content under the gastrointestinal digestion was different,especially for four toxic arsenic speciation.