| The contamination of toxic metals in the environment and biological matrices (seafood) is becoming a serious problem endangering human health. Heavy metals such as mercury, arsenic, lead, cadmium, etc, upon human uptake, are known to bio-accumulate in the body, causing severe damage on the blood, immunity, nerve and reproductive systems. Simultaneously, the determination of merely the total amount of the heavy metals in a sample is not sufficient for safety risk assessment. Elemental speciation is of vital importance because the toxicity of the hazardous element depends not only on the quantity involved, but more importantly, also the chemical forms of the element. For instance, the toxicity of methylmercury and organotin is higher than the inorganic mercury and tin, respectively. Inorganic arsenic compounds are highly toxic, while the organic forms of arsenic carry low toxicity. On the other hand, both arsenobetaine and arsenosugars are considered non-toxic. Against this background, the development of techniques for the effective determination of heavy metals and speciation in environmental and biological matrices is an area which has been attracting increasing attention in recent years.Since the introduction in 1980, inductively coupled plasma mass spectrometry (ICP-MS) has developed into an accurate and sensitive technique for multi-element determinations in a range of sample matrices. Compared with FAAS. GFAAS and ICP-OES, ICP-MS offers better sensitivity and excellent accuracy with multi-element, and has been used for all kinds of complicated samples. In this paper, These methods involving ICP-MS and HPLC-ICP-MS have been used for the determination of heavy metals and mercury species in some marine samples, and arsenic species in Chinese medicinal herbs.Main results obtained in this study can be summarized as follows:1. Certified reference material was treated with royal water circumfluence digestion, sealing vessel digestion and microwave digestion. The result of digestion was compared. The royal water circumfluence could not digest all the samples. Moreover, the latter methods completely digested marine samples. In addition, a method involving inductively coupled plasma-mass spectrometric analysis has been established and used for the determination of 12 kinds of heavy elements in marine sediments. Sediment samples collected from different positions were found to give distinct distribution patterns of trace elements. The method is first used for the investigation of the South Yellow Sea. The results provide the information about marine contaminative source.2. Toxicity and bioavailability of mercury species is highly dependent on its chemical structure. Methylmercury is the most toxic form of mercury which is particularly susceptible to bio-magnification in aquatic food webs. The accumulation of methylmercury in aquatic systems continues to pose a threat to fish and other biota including man. Speciation analysis of mercury in environmental and seafood samples has been a subject of great concern all the time. Speciation analysis of mercury is, therefore, mandatory in environmental studies. In this paper, three simple and rapid extraction methods are developed for the extraction of mercury species in sediment samples. A method employing HPLC-ICP-MS analysis has been developed for speciation analysis of inorganic mercury and organic mercury in extracts from marine sediments. The proposed method has been used for the speciation analysis of mercury in marine sediments from the South Yellow Sea. The proposed method provides an analytical approach for the understanding of migration and transformation, toxicity and the potential damage to environment of the mercury in ocean system.3. The method involving Microwave digestion and ICP-MS analysis has been established and used for the determination of four hazardous elements (As,Cd,Hg,Pb) in 36 kinds of seafood samples. The method has been validated using certified reference materials (DORM-2), assessing its quality in terms of accuracy, repeatability and detection limit. The results obtained show the validity of the proposed method to analyze real samples. Good linearity of the calibration is obtained for all target elements(r>0.9999). Detection limits for these four elements are 0.2μg/L(Cd,Pb), 0.8μg/L(Hg) and 11.3μg/L(As). These results show that the problem of hazardous elements in seafood was very serious, such as the amount of arsenic in whelk is very great and about 45.62 mg/kg.The HPLC-ICP-MS method has been combined with two extraction methodologies using alkaline digestion and acid digestion for extraction and quantitative analysis of inorganic mercury and organic mercury simultaneously in biota samples. The analytical results indicate that methyhnercury was the main chemical species in seafood samples. The percentages of MeHg in HgT were 83.5% to 94.2% in two shrimp samples from different sampling positions. The high performance of the methodology can be applied for the quality control and safety evaluation of the mercury speciation analysis in seafood. 4. In Chinese medicinal herbs, the trace element analysis is a hot topic in contemporary medicine and life sciences research. The speciation analysis of arsenic in Chinese medicinal herbs provides certain scientific basis for its toxicology research and safety evaluation. The Chinese medicinal herbs has complicated composition, and be therefore difficult to analysis. In this chapter, the method involving microwave digestion and ICP-MS analysis has been used for the determination of five hazardous elements (Cu,As,Cd,Hg,Pb) in Chinese medicinal herbs. These results indicate that the problem of poisonous element in Chinese medicinal herbs samples was very serious, more attention should be paid to this problem in the production of Chinese medicinal herbs.In addition, the development of the hyphenated technique of HPLC-ICP-MS method has been established for the separation and simultaneous determination of arsenobetaine (AsB), arsenocholine (AsC), arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). And the method was proposed for the speciation analysis of arsenic in 6 kinds of Chinese medicinal herbs. From this work, it was found that As (Ⅴ), As (Ⅲ) were the main chemical species in Chinese medicinal herbs, however, a little AsB in animal herbs. As for the merits of high sensitivity, effective separation and low detection limits, this feasible method can be applied for quality control of five hazard elements and arsenic speciation analysis in Chinese medicinal herbs. The information should be of value to scientists involved in the pharmacological research of realgar and cinnabar in Chinese medicinal herbs.
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