三疣梭子蟹和虾蛄中镉的化学形态分析

Chemical Speciation Analysis of Cadmium in Portunus trituberculatus and Oratosquilla oratoria

摘要:

本文针对三疣梭子蟹和虾蛄等甲壳类动物具有富集镉的特性，研究了运用体积排阻色谱-高效液相色谱电感耦合等离子体质谱联用技术（SEC-HPLC-ICP-MS）首次对三疣梭子蟹和虾蛄可食用组织中镉的形态进行分析，研究结果显示梭子蟹肝胰腺中总镉含量高于肌肉组织，且不同样品总镉含量差异很大，镉的形态也存在很大差异。总镉含量高的梭子蟹肝胰腺组织中Cd主要以Cd-MT（金属硫蛋白）形态存在，而总镉含量低的梭子蟹肝胰腺组织中Cd主要以Cd-Cys（半胱氨酸），梭子蟹的肌肉组织中Cd主要以Cd-Cys形态存在。虾蛄的肌肉组织中Cd主要以Cd-MT形态存在。基于本文的研究结论，建议对我国国家标准中甲壳类镉的限量标准做进一步评估和再评价研究。

Abstract:

Crustaceans are known to accumulate high concentrations of cadmium. Chemical speciation analysis of cadmium in edible tissues of two crustaceans (P. trituberculatus and O. oratoria) was performed using size exclusion chromatography-high performance liquid chromatography-inductively coupled plasma mass spectrometry (SEC-HPLC-ICP-MS). The results showed that the total cadmium content in the liver and pancreas of P. trituberculatus was higher than that in the muscle; in addition, significant differences were found between the total cadmium content in different samples and in the chemical forms of cadmium in these samples. In the liver and pancreas of P. trituberculatus samples with high cadmium content, cadmium mainly existed in the form of Cd-MT (metallothionein). Cd-Cys (cysteine) was the major form of cadmium in the liver and pancreas of samples with low cadmium content, as well as in the muscle tissues. Cadmium in the muscle tissues of O. oratoria was found to be mainly in the form of Cd-MT. These results indicated that further evaluation and assessment of the national standards in the limits of cadmium levels in crustaceans might be necessary.