16 research outputs found
Analysis of active ingredients and preservatives in creams by capillary electrochromatography (CEC)
A review of the current status of capillary electrochromatography technology and applications
Precolumn Affinity Capillary Electrophoresis for the Identification of Clinically Relevant Proteins in Human Serum: Application to Human Cardiac Troponin I
Investigation of the Chromatographic Process via Pulsed-Gradient Spin−Echo Nuclear Magnetic Resonance. Role of the Solvent Composition in Partitioning Chromatography
Centrifugal Sedimentation for Selectively Packing Channels with Silica Microbeads in Three-Dimensional Micro/Nanofluidic Devices
Incorporation of nanofluidic elements into microfluidic channels is one approach for adding filtration and partition functionality to planar microfluidic devices, as well as providing enhanced biomolecular separations. Here we introduce a strategy to pack microfluidic channels with silica nanoparticles and microbeads, thereby indirectly producing functional nanostructures; the method allows selected channels to be packed, here demonstrated so that a separation channel is packed while keeping an injection channel unpacked. A nanocapillary array membrane is integrated between two patterned microfluidic channels that cross each other in vertically separated layers. The membrane serves both as a hit for bead packing and as a fluid communication conduit between microfluidic channels. Centrifugal force-assisted sedimentation is then used to selectively pack the microfluidic channels using an aqueous silica bead suspension loaded into the appropriate inlet reservoirs. This packing approach may be used to simultaneously pack multiple channels with silica microbeads having different sizes and surface properties. The chip design and packing method introduced here are suitable for packing silica particles in sizes ranging from nanometers to micrometers and allow rapid (similar to 10 min) packing with high quality. The liquid/analyte transport characteristics of these packed micro/nanofluidic devices have potential utility in a wide range of applications, including electroosmotic pumping, liquid chromatographic separations, and electrochromatography