Simultaneous determination of anions in nanoliter volumes
Simultaneous determination of anions in nanoliter volumes
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DOI：
10.1111/j.1523-1755.2005.00089.x
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发表时间：
2005-01-01
影响因子：
19.6
通讯作者：
Unwin, RJ
中科院分区：
文献类型：
--
作者：
Faria, NJR;Dobbie, H;Unwin, RJ
背景肾小管转运的研究需要能够准确地测量从单个小管中采集的样品中的离子浓度。样品收集和分析是费力的，因此允许在小体积样品中测定多个离子种类的方法是有利的。本文介绍了一种同时分析纳升体积的小管液中生理浓度阴离子的方法。使用毛细管区带电泳进行分析。稀释样品通过批量运输沿毛细管沿着移动，并根据电荷和大小进行分离。采用紫外检测器检测出相应的阴离子峰，峰面积与离子浓度成正比。氯离子、硝酸根、柠檬酸根、磷酸根和碳酸氢根在4分钟内分离，碘酞酸根在5分钟内分离。同时进行定量分析的氯化物，磷酸盐和碳酸氢盐，证明检测限为12 fmol的氯化物，12 fmol的磷酸盐，和72 fmol的碳酸氢盐。这种方法和流通显微荧光计分析氯化物之间的比较表明，两个微型方法之间的良好协议。通过显微穿刺（体积30-70 nL）获得的近端和远端肾小管液样品的说明性数据被给出，尿液样品的结果也是如此。对照材料中氯化物、磷酸盐和碳酸氢盐的结果与认证值非常一致，而肾小管液中的值与先前发表的结果一致。该方法提供了一种简单的方法，分析小体积生物样品中的多种阴离子。
Background. The study of renal tubular transport requires the ability to accurately measure ion concentrations in samples taken from single tubules. Sample collection and analysis are laborious, so methods allowing determination of multiple ion species in a small volume sample are advantageous. This article describes a method for the simultaneous analysis of anions at physiologic concentrations in nanoliter volumes of tubular fluid.Method. The analysis is performed using capillary zone electrophoresis. Diluted samples are moved along a capillary by bulk transport and separated according to charge and size. Peaks corresponding to anions are obtained by ultraviolet (UV) detection; peak area is proportional to ion concentration.Results. The anions chloride, nitrate, citrate, phosphate, and bicarbonate were separated in less than 4 minutes, and iothalamate in less than 5 minutes. Simultaneous quantitative analysis was performed for chloride, phosphate, and bicarbonate, demonstrating detection limits of 12 fmol for chloride, 12 fmol for phosphate, and 72 fmol for bicarbonate. A comparison between this method and a flow-through microfluorimeter analysis of chloride showed good agreement between the two micro-methods. Illustrative data from proximal and distal tubular fluid samples obtained by micropuncture (volume 30-70 nL) are given, as are results from urine samples.Results. Results for chloride, phosphate, and bicarbonate in control material are in close agreement with the certified values, while values in tubular fluid are in accordance with previously published results.Conclusion. This method provides a straightforward means of analyzing multiple anions in small volume biological samples.