Development of Quadrupole Magnetic Field-Flow Fractionation: Application to Characterization of Magnetic Colloids and Microparticles

四极磁场流分级分离的发展：在磁性胶体和微粒表征中的应用

• 批准号: 0125657
• 负责人: Philip Williams
• 金额: $ 29.05万
• 依托单位: Cleveland Clinic Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125657&HistoricalAwards=false
• 关键词: Development; Quadrupole; Magnetic; Field; Flow

Development of Quadrupole Magnetic Field-Flow Fractionation: Application to Characterization of Magnetic Colloids and Microparticles.The main objective of the proposed work is to develop magnetic field-flow fractionation (MgFFF) into a powerful tool for characterizing magnetic colloids in terms of their paramagnetic component content. The various FFF techniques are elution-based separation methods in which the degree of retardation of a colloidal material depends on the strength of interaction of the colloid particles with the applied field. The quadrupole magnetic field is radially symmetrical and lends itself to an annular FFF channel geometry. Such a geometry has already been exploited for biological cell sorting using immunospecific magnetic colloid labels. A novel, helical channel geometry is proposed that will have several advantages over a simple annular channel. It has simplified inlet and outlet geometry, it will nullify the effects of varying field strength around the annular circumference, and it will have increased separation length for a given quadrupole magnet. Effort is being devoted to optimizing the channel geometry and operating conditions. The importance of carrier solution chemistry cannot be underestimated because aggregation or chaining of magnetized particles must be avoided. Quadrupole magnetic FFF offers the unique possibility of characterizing colloidal material in terms of its distribution in magnetization. Other techniques yield only a bulk, or mean value for the magnetization. Distribution information would be invaluable to the manufacturers of these materials. The inclusion of a quadrupole electromagnet will broaden the applicability of the instrument. The field strength can be adjusted to suit the magnetic properties of the sample. Using programmed decay of field strength, the instrument will be capable of characterizing magnetically polydisperse particulate samples in which magnetization varies widely from particle to particle. The method will be useful for characterizing microparticles and colloids. It will also lend itself to separation of proteins by functionalizing the surface of the particles to promote selective adsorption.

四极磁场流分级分离的发展：应用于磁性胶体和微粒的表征。这项工作的主要目标是将磁场流分级分离（MgFFF）发展成为一种强大的工具，用于表征磁性胶体的顺磁性成分含量。 各种 FFF 技术都是基于洗脱的分离方法，其中胶体材料的延迟程度取决于胶体颗粒与施加场的相互作用的强度。 四极磁场是径向对称的，适合环形 FFF 通道几何形状。 这种几何形状已被用于使用免疫特异性磁性胶体标记进行生物细胞分选。 提出了一种新颖的螺旋通道几何形状，与简单的环形通道相比，它具有多种优点。 它简化了入口和出口几何形状，将消除环形圆周周围变化的场强的影响，并且对于给定的四极磁体，它将增加分离长度。 我们正在努力优化通道几何形状和操作条件。 载体溶液化学的重要性不可低估，因为必须避免磁化颗粒的聚集或链接。 四极磁性 FFF 提供了根据磁化强度分布来表征胶体材料的独特可能性。 其他技术仅产生磁化强度的体积值或平均值。 分销信息对于这些材料的制造商来说非常宝贵。 四极电磁体的加入将扩大仪器的适用性。 可以调整磁场强度以适应样品的磁性。 使用场强的程序衰减，该仪器将能够表征磁性多分散颗粒样品，其中颗粒之间的磁化强度变化很大。 该方法可用于表征微粒和胶体。 它还可以通过对颗粒表面进行功能化以促进选择性吸附来分离蛋白质。