Magnetophoretic velocimetry of manganese(II) in a single emulsion droplet at the femtomole level.
Magnetophoretic velocimetry of manganese(II) in a single emulsion droplet at the femtomole level.
复制标题
飞摩尔水平的单个乳液液滴中锰 (II) 的磁泳测速。
DOI：
10.1021/ac010418v
复制
发表时间：
2001
影响因子：
7.4
通讯作者：
H. Watarai
中科院分区：
文献类型：
--
作者：
M. Suwa;H. Watarai
我们发展了一种新的实验技术，名为磁泳测速法，以确定在一个单一的微滴中的少量顺磁性物种。在非均匀磁场作用下，含顺磁性金属离子的水滴在有机介质中的磁泳速度可以对微量的金属离子产生响应。在本研究中用作测试样品的顺磁性液滴（2个约8微米直径）是分散在苯甲酸乙酯中的氯化锰（II）的水性液滴，其密度几乎等于水。一对小的Nd-Fe-B磁体以400 μ m的间隙放置在边缘之间产生不均匀磁场，在该不均匀磁场下，磁通密度与梯度的乘积B（dB/dx）高达410 T2 m（-1）。当含有乳液的二氧化硅毛细管插入到磁体之间的差距中时，用视频显微镜观察液滴的磁泳迁移。磁泳速度除以液滴半径的平方与液滴中的MnCl 2浓度成比例，如通过理论计算预测的。方法简单，检出限低于10（-16）mol/L。
We developed a new experimental technique named magnetophoretic velocimetry to determine a small amount of paramagnetic species in a single microdroplet. The magnetophoretic velocity of an aqueous droplet containing paramagnetic metal ion dispersed in an organic medium could response to a very small amount of the metal ion under an inhomogeneous magnetic field. The paramagnetic droplet (2 approximately 8 microm diam) used as a test sample in this study was the aqueous droplet of manganese(II) chloride dispersed in ethylbenzoate whose density was nearly equal to water. A pair of small Nd-Fe-B magnets placed with a gap of 400 microm generated an inhomogeneous magnetic field between the edges, at which the product of the magnetic flux density and the gradient, B(dB/dx), was as high as 410 T2 m(-1). When a silica capillary containing the emulsion was inserted into the gap between the magnets, the magnetophoretic migration of the droplets was observed with a video microscope. The magnetophoretic velocity divided by the squared radius of the droplet was proportional to the MnCl2 concentration in the droplet, as predicted by a theoretical calculation. The estimated detection limit in this simple method was lower than 10(-16) mol for manganese(II).