Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias s/n, 15782 Santiago de Compostela, Spain.
J Chromatogr A. 2012 May 4;1236:164-76. doi: 10.1016/j.chroma.2012.03.019. Epub 2012 Mar 9.
Anion exchange high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry has been novelly applied to assess inorganic (iodide and iodate) and organic (3-iodotyrosine - MIT, and 3,5-diiodotyrosine - DIT) iodine species in a single chromatographic run. The optimized operating conditions (Dionex IonPac AS7, gradient elution with 175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase and flow rates within the 0.5-1.5 mL min(-1) range) have also been used to perform inorganic bromine speciation analysis (bromide and bromate). The developed method has been applied for determining the bio-available contents of iodine and bromine species in dialyzates from edible seaweed. Reverse phase high performance liquid chromatography (Zorbax Eclipse XDB-C8, gradient elution with 0.2% (m/m) acetic acid, and 0.2% (m/m) acetic acid in methanol, as mobile phases, and a constant flow rate of 0.75 mL min(-1)) also hyphenated with inductively coupled plasma-mass spectrometry was used to confirm the presence of organic iodine species (MIT and DIT) in the dialyzates. The verification of the presence of iodinated amino acids (MIT and DIT) in the extracts was also performed by reverse phase high performance liquid chromatography-electrospray ionization-mass spectrometry (LTQ Orbitrap). The developed methods have provided good repeatability (RSD values lower than 10% for both anion exchange and reverse phase separations) and analytical recoveries within the 90-105% range for all cases. The in vitro bio-availability method consisted of a simulated gastric and an intestinal digestion/dialysis (10 kDa molecular weight cut-off - MWCO) two-stage procedure. Iodide and MIT were the main bio-available species quantified, whereas bromide was the major bromine species found in the extracts.
阴离子交换高效液相色谱-电感耦合等离子体质谱联用技术新颖地应用于在单次色谱运行中评估无机（碘化物和碘酸盐）和有机（3-碘酪氨酸 - MIT 和 3,5-二碘酪氨酸 - DIT）碘形态。还使用优化的操作条件（Dionex IonPac AS7，梯度洗脱，流动相为 175 mM 硝酸铵加 15%（v/v）甲醇，pH 值 3.8，流速在 0.5-1.5 mL min(-1)范围内）进行无机溴形态分析（溴化物和溴酸盐）。所开发的方法已应用于测定可食用海藻透析液中碘和溴形态的生物可利用含量。反相高效液相色谱（Zorbax Eclipse XDB-C8，梯度洗脱，流动相为 0.2%（m/m）乙酸和 0.2%（m/m）甲醇中的乙酸，恒流速为 0.75 mL min(-1)）与电感耦合等离子体质谱联用也用于确认透析液中有机碘形态（MIT 和 DIT）的存在。通过反相高效液相色谱-电喷雾电离-质谱（LTQ Orbitrap）也验证了提取物中碘化氨基酸（MIT 和 DIT）的存在。所开发的方法提供了良好的重复性（阴离子交换和反相分离的 RSD 值均低于 10%）和 90-105%范围内的分析回收率。体外生物利用度方法包括模拟胃和肠消化/透析（10 kDa 分子量截止 - MWCO）两步程序。定量了主要的生物可利用形态为碘化物和 MIT，而溴化物是提取物中主要的溴形态。
