Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, 20224, Taiwan.
Department of Biomedical Engineering and Environmental Sciences, National Tsing-Hua University, Hsinchu, 30013, Taiwan.
Anal Chim Acta. 2017 Feb 8;953:87-94. doi: 10.1016/j.aca.2016.11.052. Epub 2016 Dec 2.
Exploration of brain extracellular non-protein-bound/diffusible iron species remains a critically important issue in investigations of free radical biology and neurodegenerative diseases. In this study, a facile sample pretreatment scheme, involving poly(vinyl chloride)-metal ion interactions as a selective extraction procedure, was optimized in conjunction with microdialysis (MD) sampling and inductively coupled plasma mass spectrometry (ICP-MS) in cool-plasma mode for in vivo online monitoring of rat brain extracellular Fe(II) and Fe(III) species. Optimization of the system provided detection limits in the range 0.9-6.9 μg Fe L, based on a 12-μL microdialysate, for the tested iron species; relative standard deviations of the signal intensities during 7.8 h of continuous measurement were less than 9.4%-sufficient to determine the basal concentrations of rat brain extracellular Fe(II) and Fe(III) species and to describe their dynamic actions. The method's applicability was verified through (i) spike analyses of offline-collected rat brain microdialysates, (ii) determination of the basal Fe(II) and Fe(III) concentrations of living rat brain extracellular fluids, and (iii) monitoring of the dynamic changes in the Fe(II) and Fe(III) concentrations in response to perfusion of a high-K medium. This proposed sample pretreatment scheme, based on polymer-metal ion interactions and hyphenation to an MD sampling device and an ICP-MS system, appears to have great practicality for the online monitoring of rat brain extracellular diffusible iron species.
探索脑细胞外非蛋白结合/可扩散铁物种仍然是自由基生物学和神经退行性疾病研究中的一个至关重要的问题。在这项研究中，我们优化了一种简单的样品预处理方案，该方案涉及聚氯乙烯-金属离子相互作用作为一种选择性提取程序，并与微透析（MD）采样和电感耦合等离子体质谱（ICP-MS）在冷等离子体模式下结合，用于体内在线监测大鼠脑细胞外 Fe(II)和 Fe(III)物种。该系统的优化提供了基于 12 μL 微透析液的检测限，范围为 0.9-6.9μg Fe L，用于测试的铁物种；在 7.8 h 的连续测量过程中，信号强度的相对标准偏差小于 9.4%-足以确定大鼠脑细胞外 Fe(II)和 Fe(III)物种的基础浓度，并描述它们的动态作用。该方法的适用性通过以下方法得到验证：（i）离线收集的大鼠脑微透析液的加标分析，（ii）测定活鼠脑细胞外液中基础 Fe(II)和 Fe(III)浓度，以及（iii）监测高 K 介质灌注时 Fe(II)和 Fe(III)浓度的动态变化。基于聚合物-金属离子相互作用以及与 MD 采样装置和 ICP-MS 系统的连接，这种提议的样品预处理方案似乎对于大鼠脑细胞外可扩散铁物种的在线监测具有很大的实用性。
