| Summary: | 碩士 === 國立中山大學 === 化學系研究所 === 102 === The purpose of the first study was to assess the arsenic species content in the fishes and hoped for using the principal component analysis (PCA) to discriminate the different fishes. The determination of arsenic species in fishes was performed using ion exchange chromatography on a PRP X-100 column with inductively coupled plasma mass spectrometry detection after two step microwave assisted extraction. The arsenic species studied were arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB) and arsenocholine (AsC). Chromatographic separation of all the species was achieved in &;lt;8 min in gradient elution mode using (NH4)2CO3 and methanol at pH 8.5. The six extraction methods on arsenic extraction recoveries was evaluated in real sample. The recovery of arsenic species with the two step extraction ( MeOH / Mobile phase A and 1% nitric acid) in real samples were up to 94%. The limits of detection were in the range of 0.005−0.011 μg L−1 for various arsenic species based on peak height.
The purpose of the second study was to develop a method for separating the cobalt species and assess the species content in the functional drinks, nutritive supplements and seaweeds. The determination of cobalt species in functional drinks and nutritive supplements was performed using reversed phase chromatography on C8 micropore column with inductively coupled plasma mass spectrometry detection after microwave assisted extraction. The cobalt species studied were cobalt [Co(II)], hydroxocobalamin (OH-Cbl), cyanocobalamin (CN-Cbl), 5’-deoxyladenosylcobalamin (Ado-Cbl) and methylcobalamin (Me-Cbl). The species were separated by using NH4OAc and acetonitrile at pH 4.0 as elution solution, operated in a stepwise mode, yielded well resolved chromatograms of all the species within 15 min. The five extraction methods on cobalt extraction recoveries was evaluated in real sample. The recovery of arsenic species with the two step extraction (0.5% nitric acid) in real samples were up to 91%. The detection limits of the procedure were 0.007−0.031 μg L−1 for various cobalt species based on peak height.
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