摘要-
　　海水中含有許多複雜且高濃度的鹽類基質，因此分析海水微量元素一直是很困難且具挑戰性的工作。過去幾年來，由於熱游離質譜儀和感應耦合電漿質譜儀的應用，大幅降低儀器偵測極限，然而仍需配合更有效的純化與分離技術，以降低基質干擾及背景污染，才能使分析更為精確。
　　
　　本研究選擇ORI-679航次於南沖繩海域及ORI-688航次於南海SEATS測站C附近所採取海水剖面的水樣，以Chelex-100樹脂濃縮海水中微量金屬元素（鎘，Cd；鈾，U），並配合高解析感應耦合電漿質譜儀（HR-ICP-MS, Element II）精確量測邊緣海地區海水Cd、U濃度及U同位素分佈，可作為元素Cd和U在生物地球化學作用與傳輸過程上的重要依據。首先以已知濃度國際標準海水樣品- NASS-5 (Cd：23.0±3.0ppt，U：2.60±0.03 ppb)，系統性評估此方法的適用性。初步結果顯示其回收率可達99%以上，且可移去大部分海水中的主要鹽類基質，實驗室測值Cd：32.0±1.1ppt，而Cd的分析精度可優於3% (2σ)；U的實驗室測值為2.59±0.06ppb，分析精度優於2% (2σ)，而U同位素則可達3-4‰(2σ)。
　　
　　Cd濃度於台灣東北部海域表水的水平分佈，其濃度範圍為14.2-23.5 ppt，愈靠近大陸邊緣其濃度測值較高，明顯受到陸源沖淡水或渦流所造成區域性湧升作用所影響。而台灣東北部及南海海域之海水剖面都可觀察到Cd在海水中垂直分佈均如營養鹽型元素一般，表面濃度甚低而隨深度逐漸增加，於水深約1000m處出現極高值（SOT：約102.4ppt；SCS：約112.2ppt），此外南海海水500m處 Cd之平均濃度高於開放大洋。而在SOT附近Cd的海水剖面也同樣呈現營鹽型分佈，與Hsu et al. [2003]之結果明顯不同，推測應與季節性渦流發育之強弱有關。
　　
　　SOT表層海水U濃度水平分佈顯示距東海陸棚越遠濃度逐漸增加，配合海水U同位素結果，推測此區主要受東海陸棚水與黑潮水或海底地下水混合所控制。而SOT之U濃度隨深度的分佈於水深200m內有明顯變化(約為2.62-3.38ppb），與前人研究大洋保守且均勻混合的結果有差異，此部分有待後續研究加以探討可能控制因子；深部則無顯著變化。南海（St-C）海水U與U同位素垂直分佈顯示於最表層海水出現U濃度極低值(2.98±0.05ppb），(234U/238U)AR則為相對高值(1.157±0.004)，應與南海周遭大河注入大量淡水有關；而深部海水U及其同位素變化趨勢與開放大洋相似。

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中文書籍-
江旭楨、楊惠珍（1992）質譜分析術專輯，行政院國家科學委員會精密儀器發展中心，
共390頁。

中文期刊-
東海海洋（1995），第13卷，第3-4期。
黃潔瑩（2002）利用Chelex-100鉗合樹脂濃縮法測定台灣西南海域海水中之鎳、鎘、銅及鉛，台灣大學海洋研究所碩士論文，共117頁。

英文期刊文獻-
Alibo, D.S. and Nozaki, Y. (2000) Dissolved rare earth elements in the South China Sea:Geochemical characterization of the water masses. Journal of Geophysical Research 105, C12, 28771-28783.
Abdullah, M.I., El-Rayis, O.A., and Riley, J.P. (1976) Reassessment of chelating ion-exchange resins for trace metals analysis of seawater. Analytica Chimica Acta 84, 363-368.
Andersson, P.S., Wasserburg, G.J., Papanastassiou, D.A. and Ingri, J. (1995)
238U-234U and 232Th-230Th in the Baltic Sea and in the river water. Earth and Planetary Science Letters 130, 217-234.
Atanassova, D., Stefanova, V. and Russeva, E. (1998) Co-precipitative pre-concentration with sodium diethyldithiocarbamate and ICP-AES determination of Se, Cu, Pb, Zn, Fe, Co, Ni, Mn, Cr and Cd in water. Talanta 47, 1237-1243.
Barnes, C.E. and Cochran, J.K. (1990) Uranium removal in oceanic sediments and the oceanic U balance. Earth and Planetary Science Letters 97, 94-101.
Barnes, C.E. and Cochran, J.K. (1993) Uranium geochemistry in estuarine sediments: controls on removal and release processes. Geochim. Cosmochim. Acta 57, 555-569.
Batterham, G.J. and Parry, D.L. (1996) Improved dithiocarbamate/oxine solvent extraction method for the preconcentration of trace metals from seawater using metal exchange back-extraction. Marine Chemistry 55, 381-388.
Beauchemin, D., McLaren, J.W., Mykytiuk, A.P. and Berman, S.S. (1988) Determination of Trace Metals in an Open Ocean Water Reference Material by Inductively Coupled Plasma Mass Spectrometry. Journal of Analytical Atomic Spectrometry 3, 305-308.
Bertine, K.K., Chan, L.H. and Turekian, K.K. (1970) Uranium determinations in deep-sea sediments and natural waters using fission tracks. Geochim. Cosmochim. Acta 34, 641-648.
Bio-Rad Laboratories (2000) Chelex-100 and Chelex-20 Chelating Ion Exchange Resin Instruction Manual.
Boyle, E.A., Sclater, F. and Edmond, J.M. (1976) On the marine geochemistry of cadmium. Nature 263, 42-44.
Boyle, E.A. and Edmond, J.M. (1977) Determination of copper, nickel, cadmium in sea water by APDC chelate coprecipitation and flameless atomic absorption spectrometry. Anal. Chim. Acta. 91, 189-197.
Boyle, E.A. and L.D. Keigwin (1985/6) A Comparison of Paleochemical Records from the North Atlantic and North Pacific Ocean: Changes in Deep Ocean Circulation and Chemical Inventories. Earth Planet. Sci. Lett. 76, 135-150.
Boyle E.A., Chapnnick, S.D. and Shen, G.T. (1986) Temporal variability in the western north Atlantic. Journal of Geophysical Research 91, 8573-8593.
Boyle, E.A. and L.D. Keigwin (1987) North Atlantic thermohaline circulation during the last 20,000 years: link to high latitude surface temperature. Nature 330, 35-40.
Broecker, W.S., Patzert, W.C., Toggweiler, J.R. and Stuiver, M. (1986) Hydrography, chemistry, and radioisotopes in the southeastern Asian basins. Journal of Geophysical Research 91, 14345- 14354.
Bruland, K.W. (1980) Oceanogrpahic distributions of cadmium, zinc, nickel, and copper in the north Pacific. Earth Planet. Sci. Lett. 47, 176-198.
Bruland, K.W., Knauer, G.A. and Martin, J.H. (1978) Cadmium in northeast Pacific water. Limnol. Oceanogr. 23, 618-625.
Bruland, K.W. (1983) Trace elements in seawater. In: J. P. Riley and R. Chester (Editors), Chemical Oceanography 8, 157-221.
Bruland, K.W., Coale, K.H. and Mart, L. (1985) Analysis of seawater for dissolved cadmium, copper, and lead: and intercomparison of voltammetric and atomic absorption methods. Mar. Chem. 17, 285-300.
Bruland, K.W., Orians, K.J. and Cowen, J.P. (1994) Reactive trace metals in the stratified central North Pacific. Geochimica et Cosmochimica Acta 58, 3171-3182.
Chen, J.H., Edwards, R.L. and Wasserburg, G..J. (1986) 238U, 234U and 232Th in seawater. Earth and Planetary Science Letters 80, 241-251.
Chen, C.T.A., Ruo, R., Pai, S.C., Liu, C.T. and Wong, G.T.F. (1995) Exchange of water masses between the East China Sea and the Kuroshio off northeastern Taiwan. Continental Shelf Research 15, 19-39.
Chen, C.T.A. (1996) The Kuroshio intermediate water is the major source of nutrients on the East China Sea continental shelf. Oceanol. Acta 19, 523-527.
Chen, H.Y., Fang, T.H., Wen, L.S. (2005) A preliminary study of the distributions of Cd in the South China Sea. Continental Shelf Research 25, 297-310.
Chern, C.S., Wang, J. and Wang, D.P. (1990) The exchange of Kuroshio and the East China Sea shelf water. J. Geophys. Res. 95, 16017-16023.
Chou, C.L. and Moffatt, J.D. (2000) A simple co-precipitation inductively coupled plasma mass spectrometric method for the determination of uranium in seawater. Fresenius J. Anal. Chem. 368, 59-61.
Chu, P.C., Fan, C., Lozano, C.J. and Kerling, J.L. (1998) An airborne expendable bathy- thermography survey of the South China Dea, May, 1995. Journal of Geophysical Research 103, 21637-21652.
Church, T.M., Sarin, M.M., Fleisher, M.Q. and Ferchlman, T.G. (1996) Salt marches: an important sink for dissolved uranium. Geochim. Cosmochim. Acta 60, 3879-3887.
Cullen, J.T., Lane, T.W., Morel, F.M.M. and Sherrell, R.M. (1999) Modulation of cadmium uptake in phytoplankton by seawater CO2 concentration. Nature 402, 165-167.
Delanghe, D., Bard, E. and Hamelin, B. (2002) New TIMS constraints on the uranium-238 and uranium-234 in seawater from the main ocean basins and the Mediterranean Sea. Marine Chemistry 80, 79-93.
Delgadillo-Hinojosa, F., Macías-Zamora, J.V., Segovia-Zavala, J.A. and Torres-Valdés, S. (2001) Cadmium enrichment in the Gulf of California. Marine Chemistry 75, 109-122.
Dunk, R.M., Mills, R.A. and Jenkins, W.J. (2002) A reevaluation of the oceanic uranium budget for the Holocene. Chemical Geology 190, 45-67.
Dupre, B., Gaillardet, J., Rousseau, D. and Allegre, C.J. (1996) Major and trace elements of river-borne material: the Congo basin. Geochim. Cosmochim. Acta 60, 1301-1321.
Ferrareello, C.N., Bayon, M.M., Alonso, J.I. and Sanz-Medel, A. (2001) Comparison of metal pre-concentration on immobilized Kelex-100 and quadrupole inductively coupled plasma mass spectrometric detection with direct double focusing inductively coupled plasma mass spectrometric measurements for ultratrace multi-element determinations in seawater. Analytica Chimica Acta 429, 227-235.
Ferreira, A.C., Costa, A.C.S. and Korn, M.G.A. (2004) Preliminary evaluation of the cadmium concentration in seawater of the Salvador City, Brazil. Microchemical Journal 78, 77-83.
Field, M.P., Cullen, J.T. and Sherrell, R.M. (1999) Direct determination of 10 trace metals in 50μL samples of coastal seawater using desolvating micronebulization sector field ICP-MS. J. Anal. At. Spectrom. 14, 1425-1431.
Figueres, G., Martin, J.M. and Thomas, A.J. (1982) River input of dissolved uranium to the oceans: the Zaire river and estuary. Oceanol. Acta 5, 141-147.
Gong, K.C., Liu, K.K., Liu, C.T. and Pai, S.C. (1992) The chemical hydrography of the South China Sea west of Luzon and a comparison with the west Philippine Sea. Terr. Atmos. Oceanic Sci., 3, 587-602.
Hayward, T.L. and Mantyla, A.U. (1990) Physical, chemical and biological structure of a coastal eddy near Cape Mendocino. J. Mar. Res. 48, 825-850.
Henderson, G.H., Slowey, N.C. and Haddad, G.A. (1999) Fluid flow through carbonate platforms: constraints from 234U/238U and Cl- in Bahamas pore-waters. Earth and Planetary Science Letters 169, 99-111.
Henderson, G.H. (2002) Seawater (234U/238U) during the last 800 thousand years. Earth and Planetary Science Letters 199, 97-110.
Hsu, S.C., Lin, F.J., Jeng, W.L. and Tang, T.Y. (1998) The effect of a cyclonic eddy on the distribution of lithogenic particles in the southern East China Sea. J. Mar. Res. 56, 813-832.
Hsu, S.C., Lin, F.J., Jeng, W.L. and Tang, T.Y. (2003) Spatial distribution of cadmium over a cyclonic eddy in the southern East China Sea. Journal of Marine Systems 39, 153-166.
Hsueh, Y. (2000) The Kuroshio in the East China Sea. J. Mar. Syst. 24, 131-139.
Huh, C.-A., Zahnle, D.L., Small, L.F. and Noshkin, V.E. (1987) Budgets and behaviors of uranium and thorium isotopes in Santa Monica Basin Sediments. Geochim. Cosmochim Acta. 51, 1743-1754.
Klinkhammer, G.P. and Palmer, M. R. (1991) Uranium in the oceans: Where it goes and why. Geochimica et Cosmochimica Acta 5, 1799-1806.
Kinrade, J.D. and Van Loon, J.C. (1974) Solvent extraction for use with flame atomic absorption spectrometry. Anal. Chem. 46, 1894-1898.
Ku, T.L., Knauss, K.G. and Mathieu, G.G. (1977) Uranium in open ocean:concentration and isotopic composition. Deep- Sea Research 24, 1005-1017.
Lee, K.H., Oshima, M. and Motomizu, S. (2002) Inductively coupled plasma mass spectrometric determination of heavy metals in sea-water samples after pre-treatment with a chelating resin disk by an on-line flow injection method. Analyst 127, 769-774.
Li, L., Nowlin, W.D. and Lilan, S. (1998) Anticyclonic rings from the Kuroshio in the South China Sea. Deep Sea Research, Part I, 45, 1469-1482.
Liu, K.K., Gong, G.C., Shyu, C.Z., Pai, S.C., Wei, C.L. and Chao, S.Y. (1992) Response of Kuroshio upwelling to the onset of northeast monsoon in the sea north of Taiwan: observation and a numerical simulation. J. Geophys. Res. 97, 12511-12526.
Liu, K.K., Chao, S.Y., Shaw, P.T., Gong, G.C., Chen, C.C. and Tang, T.Y. (2002) Monsoon-forced chlorophyll distribution and primary production in the South China Sea: observations and a numerical study. Deep-Sea Research I 49, 1387-1412.
Löscher, B.M., van der Meer, J., de Baar, H.J.W., Saager, P.M. and de Jong, J.T.M. (1997) The global Cd/phosphate relationship in deep ocean waters and the ned for accuracy. Marine Chemistry 59, 87-93.
Löscher, B.M., de Jong, J.T.M. and de Baar, H.J.W. (1998) The distribution and preferential biological uptake of cadmium at 6°W in the Southern Ocean. Marine Chemistry 62, 259-286.
Lovley, D.R. and Phillips, E.J.P. (1992) Reduction of uranium by Desulfovibrio desulfuricans. Appl. Environ. Microbiol. 58, 850-856.
Lovley, D.R., Uidman, P.K., Woodward, J.C. and Phillips, E.J.P. (1993) Reduction of uranium by cytochrome C3 of Desulfovibrio vulgaris. Appl. Environ. Microbiol. 59, 3572-3576.
Luo, X., Rehkämper, M., Lee, D.C. and Halliday, A.N. (1997) High precision 230Th/232Th and 234U/238U measurements using energy-filtered ICP magnetic sector multiple collector mass spectrometry. International Journal of Mass Spectrometry and Ion Processes 171, 105-117.
Maeda, M. and Windom, H.L. (1982) Behavior of uranium in two estuaries of the southeastern United States. Mar. chem. 11, 427-436.
Martin, J.M., Meybeck, M. and Pusset, M. (1978) Uranium behaviour in the Zaire Estuary. Neth. J. Sea Res. 12, 338-344.
McLaren, J.M., Mykytiuk, S.N., Willie, S.N. and Berman, S.S. (1985) Determination of Trace Metals in Seawater by Inductively Coupled Plasma Mass Spectrometry with Perconcentration on Silica-Immobilized 8-Hydroxyqinoline. Anal. Chem. 57, 2907-2911.
McManus, J., Berelson, W.M., Klinkhammer, G.P., Johnson, K.S., Coale, M., nderson, R.F., Kumar, N., Burdige, D., Hammond, D.E.,, Brumsack, H.S., McKorkle, D. and Rushdi, A. (1998) Geochemistry of barium in marine sediments:implication for its use as a paleoproxy. Geochimica et Cosmochimica Acta 62, 3453-3473.
Moore, W.S. (1967) Amazon and Mississippi river concentrations of uranium, thorium and radium isotopes. Earth Planet. Sci. Lett. 2, 231-234.
Nitani, H. (1972) Beginning of the Kuroshio, in Kuroshio, edited by H. Stommel and Y. Yoshida, pp. 129-163. Univ. of Wash. Press, Seattle.
Pai, S.C., Whung, P.Y. and Lai, R.L. (1988) Pre-concentration efficiency of Chelex-100 resin for heavy metals in sea water, Part 1. Effects of pH and salts on the distribution ratios of heavy metals. Anal. Chim. Acta 211, 257-270.
Pai, S.C. (1988) Pre-concentration efficiency of Chelex-100resin for heavy metals in seawater, Part 2. Distribution of heavy metals on a Chelex-100 column and optimization of the column efficiency by a plate simulation method. Anal. Chim. Acta 221, 271-280.
Pai, S.C., Fang, T.H., Chen, C.T. and Jeng, K.L. (1990) A low contamination Chelex-100 technique for shipboard pre-concentration of heavy metals in seawater. Marine Chemistry 29, 295-306.
Pai S.C. and Chen, H.Y. (1994) Vertical distribution of cadmium in marginal seas of the western Pacific Ocean, Marine Chemistry, 47, 81-91.
Palmer, M.R. and Edmond, J.M. (1993) Uranium in river water. Geochim. Cosmochim. Acta 57, 4947-4955.
Rengarajan, R., Sarin, M.M., Krishnaswami, S. (2003) Uranium in the ArabianSea: role of denitrification in controlling its distribution. Oceanologica Acta 26, 687-693.
Riley, J.P. and Taylor, D. (1972) The concentrations of cadmium, copper, iron, manganese, molybdenum, nickel, vanadium and zinc in part of the tropical north-east Atlantic Ocean. Deep-Sea Research 19, 307-317.
Saager, P.M., de Baar, H.J.W. and Howland, R.J. (1992) Cd, Zn, Ni and Cu in the Indian Ocean. Deep-Sea Research 39, 9-35.
Saager, P.M., de Baar, H.J.W., de Jong, J.T.M., Nolting, R.F. and Schijf, J. (1997) Hydrography and local sources of dissolved trace metals Mn, Ni, Cu and Cd in the northeast Atlantic Ocean. Marine Chemistry 57, 195-216.
Swarzenski, P.W., Mckee, B.A., Skei, J.M. and Todd, J.F. (1999) Uranium biogeochemistry across the redox transition zone of a permanently stratified fjord: Framvaren. Norway. Mar. Chem. 67, 181-198.
Tang, T.Y. and Yang, Y.J. (1993) Low frequency current variability on the shelf break northeast of Taiwan. J. Oceanogr. 49, 193-210.
Tang, T.Y., Hsueh, Y., Yang, Y.J. and Ma, J.C. (1999) Continental slope flow northeast of Taiwan. J. Phys. Oceanogr. 29, 1353-1362.
Van der Loeff, M.R., Helmers, E. and Katner, G. (1997) Continuous transects of cadmium, copper, and aluminium in surface waters of the Atlantic Ocean, 50°N to 50°S: correspondence and contrast with nutrient-like behavior. Geochimica et Cosmochimica Acta 61, 47-61.
Veeh, H.H. (1967) Deposition of uranium from the ocean. Earth Planet. Sci. Lett. 3, 145-150.
Veeh, H.H., Moore, W.S. and Smith, S.V. (1995) The behaviour of uranium and radium in an inverse estuary. Continental Shelf Research 15, 1569-1583.
Weiss, D., Boyle, E.A., Chavagnac, V., Herwegh, M. and Wu, J. (2000) Determination of lead isotope ratios in seawater by quadrupole inductively coupled plasma mass spectrometry after Mg(OH)2 co-precipitation. Spectrochimica Acta Part B 55, 363-374.
Wiesner, M.G., Zheng, L., Wong, H.K., Wang, Y. and Chen, W. (1996) Fluxes of particulate matter in the South china Sea. In “Particle flux in the Ocean” (V. Ittekkot, P. Schofer, S. Honjo, and P.J. Depetris, Eds.), pp. 293-312. John Wiley and Sons Ltd., London.
Windom, H., Smith, R., Niencheski, F. and Alexander. (2000) Uranium in rivers and estuaries of globally diverse, smaller watersheds. Marine Chemistry 68, 307-321.
Wu, J. and Boyle, E.A. (1998) Determination of iron in seawater by high-resolution isotope dilution inductively coupled plasma mass spectrometry after Mg(OH)2 coprecipitation. Analytica Chimica Acta 367, 183-191.
Wyrtki, K. (1961) Physical Oceanography of the Southeast Asian Waters, in Scientific Results of Marine Investigations of the South China Sea and the Gulf of Thailand, NAGA Rep., vol. 2, 195 pp., Scripps Instit. Of Oceanogr., La Jolla, Calif