砷元素长期以来被认为是一种对人体健康有负面影响的元素，例如无机砷不但具有急性毒作用，在长时间低浓度的摄入下，还有致癌、致畸等慢性毒作用。而近代研究发现，砷元素的毒性大小是随着化合物的形态不同而变化的，有机砷的毒性一般比无机砷小的多，甚至有些形态有机砷的生理毒性不到无机砷的千分之一。所以，砷元素的形态分析非常重要，特别是在食品安全性方面。 论文在砷元素形态分析方法学方面对HPLC－HGAAS联用技术进行了实验研究。主要成果有：⑴设计了HPLC与AAS之间的接口装置，将紫外光催化降解装置，氢化物发生系统和气液分离器等部件集成于一小箱体内，使之具有对砷化物的在线消解、氢化物发生等功能，该装置解决了HPLC和AAS联用技术的关键问题，并具有色谱峰展宽小、集成度高等特点；⑵在上述接口技术的基础上，建立了HPLC－HGAAS联用技术分离检测As(III)、As(V)、MMA和DMA等多种砷化合物的推荐操作程序，并进行了分离度、检出限、线性范围和重现性等技术指标的测试；⑶通过与砷元素形态分析的较为成熟的方法HPLC－ICP－MS法在测定实际样品时的比较，验证了HPLC－HGAAS方法的可靠性、准确度。本工作以丰富的信息表明：HPLC－HGAAS方法对砷元素形态分析的研究工作，是一种价格低廉、操作简便、性能可靠的方法。 论文的另一部分工作是利用仪器联用方法对中国海产品当中的含砷情况做了较详细的调查，并对其食用安全性作出了评估。主要成果是：⑴对中国市场上销售的海产鱼、虾、蟹、贝和紫菜、海带等海产食品进行了所含砷化物的形态调查。调查的结果表明，中国海产品总砷含量较高，且随着种类和海域不同而变化，但超过99％的砷是有机形态的砷化合物，如砷甜菜碱和砷糖等，毒性极小。⑵重点考察了紫菜这种常见食品当中所含砷的形态分布，及其在烹饪过程和人体代谢过程中的变化情况，从而对紫菜这种含砷量较高的海产食品的食用安全性有一个较完整的评价。以上一系列结果为我国海产品的食用安全性评价提供了重要的信息，并在前人基础上进一步丰富了食品当中常见砷形态的热处理安全性和代谢安全性方面的知识。

Arsenic has a century-long reputation of being poisonous. For example, the inorganic arsenic compounds, such as arsenite and arsenate, are toxic and carcinogenic. Ingestion of inorganic arsenic may cause cancer of the skin, bladder, kidney, lungs, and liver. However, the toxicity of arsenic is greatly dependent on its chemical form. In fact, the major forms in most marine organisms, which are organic arsenic compounds such as arsenobetaine (AsB) and arsenosugars, are considered to be nontoxic. For this reason, the determination of the total amount of arsenic in a sample is not sufficient to assess the risk from eating seafood, and speciation analysis is necessary. In present dissertation, experimental studies of the arsenic speciation by using high performance liquid chromatography (HPLC) coupled hydride generation atomic absorption spectrometry (HGAAS) were carried out. The main achievements obtained in this research are: ⑴ An efficient interface between HPLC and AAS was designed, which hold an UV-digestion part, a hydride generation system and a gas-liquid separator in a small box. It was provided with some functions such as on-line digestion and hydride generation for arsenic compounds, which discussed several important practical aspects for on-line coupling of HPLC to AAS. And it had two advantages: first, the broaden of peak has been effectively solved; second, the goal of miniaturization of instrument was achieved. ⑵ Based on the interface technology, the standard operation procedure (SOP) of speciation of As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) by using HPLC－HGAAS was developed. In order to obtain the method performance characteristics, the following parameters were determined: Resolution factor, Limit of detection, Repeatability and Linearity range. ⑶Verification of the method by another technique was performed by analyzing spiked samples both with HPLC－HGAAS and HPLC－ICP－MS. The results showed HPLC－HGAAS with low cost, easy operation and high performance was successfully applied to the speciation analysis of arsenic In the second part of present dissertation, thirty different types of Chinese edible seafood, including brown algae, red algae, fish, crab, shrimp, mussels, oysters, and clams, which are very popular foodstuffs in the Chinese kitchen, were examined for their total content of As as well as its different species. The arsenic species in seafood extracts were determined by hyphenated technique. The results showed high levels of arsenic were found in seafood, but the major share of arsenic components in seafood were organic arsenic with a low toxicity, we can conclude that arsenic in seafood does not pose any risk to human health. The study was carried out to investigate the chemical changes of these organoarsenic compounds in Porphyra products during the cooking period and human ingestion. We observed that the arsenosugars were stable during a series of familiar cooking methods, such as boiling, steaming, microwaving and frying. However, when the sample was baked in a temperature higher than 200 °C, the arsenosugar may undergo changed during heating, being transformed into another, more toxic species, such as arsenate and arsenite. The metabolites of these arsenosugars in human urine after ingestion of seaweed were also studied. The results are helpful not only in the evaluation of seafood safety but also in understanding the metabolism and the possible adverse health effects of arsenosugars in humans.