Sensitive iodine speciation in seawater by multi-mode size-exclusion chromatography with sector-field ICP-MS
Sensitive iodine speciation in seawater by multi-mode size-exclusion chromatography with sector-field ICP-MS
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DOI：
10.1039/c0ja00270d
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发表时间：
2011-09
影响因子：
3.4
通讯作者：
Jian Zheng;M. Yamada;S. Yoshida
中科院分区：
文献类型：
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作者：
Jian Zheng;M. Yamada;S. Yoshida
建立了一种简单、快速、灵敏的多模式体积排阻色谱-扇形场电感耦合质谱（HPLC-SF-ICP-MS）分析海水中碘形态的方法。用1% TMAH稀释100倍后，使用SF-ICP-MS直接测量总碘浓度。使用AsahiPak GS-220多模式尺寸排阻柱实现碘酸盐和碘化物的分离，其中移动的流动相为50 mM丙二酸-37.5 mM TMAH（pH 6.9），流速为1.0 ml min-1的等度洗脱。碘酸盐的检测限为0.00016 μM（20 ng l−1），碘化物的检测限为0.00024 μM（30 ng l−1）。比HPLC-ICP-QMS技术低70倍。所提出的方法已成功地应用于测定的碘酸盐和碘化物的海水从表面到700米的深度收集从太平洋的青森县，日本。利用所建立的方法得到了总碘、碘酸盐、碘化物、总无机碘和溶解有机碘的垂直分布。发现碘酸盐是主要物质。本文首次报道了用HPLC-ICP-MS技术研究海水中碘的垂直分布。
A simple, fast and sensitive analytical method for iodine speciation in seawater by multi-mode size exclusion chromatography coupled with sector-field inductively coupled mass spectrometry (HPLC-SF-ICP-MS) is described in this paper. Total iodine concentration was directly measured using SF-ICP-MS after 100-fold dilution with 1% TMAH. Separation of iodate and iodide was achieved using an AsahiPak GS-220 multi-mode size exclusion column with a mobile phase of 50 mM malonic acid–37.5 mM TMAH (pH 6.9) with isocratic elution at a flow rate of 1.0 ml min−1. The detection limit was 0.00016 μM (20 ng l−1) for iodate and 0.00024 μM (30 ng l−1) for iodide, and they were ca. 70 times lower than those of the HPLC-ICP-QMS technique. The proposed method was successfully applied to the determination of iodate and iodide in seawaters from the surface down to a depth of 700 m collected from the Pacific Ocean off Aomori Prefecture, Japan. Vertical distributions of total iodine, iodate, iodide, total inorganic iodine and dissolved organic iodine were obtained using the developed method. Iodate was found to be the predominant species. This is the first report on the study of vertical distributions of iodine in seawater using the HPLC-ICP-MS technique.