32 results about "Flow Field-Flow Fractionation" patented technology

This invention relates generally to the field of field-flow-fractionation. In particular, the invention provides apparatuses and methods for the discrimination of matters utilizing acoustic force, or utilizing acoustic force with electrophoretic or dielectrophoretic force, in field flow fractionation.

A method for multi-dimensional chromatography of a polyolefin polymer, comprising introducing a solution of the polyolefin polymer into a liquid flowing through a first liquid chromatography stationary phase or a field flow fractionation device and subsequently flowing the solution through a second liquid chromatography stationary phase, the second liquid chromatography stationary phase comprising graphitic carbon, the polyolefin polymer emerging from the liquid chromatography stationary phase with a retention factor greater than zero.

An improved field-flow fractionation method and apparatus for the separation of sample species 28 contained in a carrier fluid, wherein a stream of the sample species-containing carrier fluid is forced through a flow channel 14 having a depletion wall 18, an accumulation wall 20, side walls, a channel inlet 10, and a channel outlet 34, by introducing the sample species-containing carrier fluid into the flow channel 14 through the channel inlet 10 and withdrawing the sample species-containing carrier fluid through the channel outlet 34, a field 32 is applied to the carrier fluid in the flow channel 14 to induce a driving force on the sample species 28 acting across the flow channel 14 from the depletion wall 18 towards the accumulation wall 20 and perpendicular to the orientation of the main axis of the flow channel 14, the sample species 28 are subjected to fractionation as they flow through the flow channel 14 and emerge as sample species fractions at the channel outlet 34, wherein at least one additional stream of sample species-depleted carrier fluid is introduced into the flow channel 14 through at least one orifice 12 and the relative flow rates of the different streams are adjusted such that the stream of sample species-containing carrier fluid is positioned adjacent to the accumulation wall 20 and the sample species-depleted carrier fluid is positioned between the depletion wall 18 and the sample species-containing carrier fluid, no mechanical barrier being provided inside the flow channel 14 between the orifice 12 and the channel inlet 10 for separating the stream of sample species-depleted carrier fluid introduced through the orifice 12 and the stream of sample species-containing carrier fluid introduced through the channel inlet 10.

Apparatuses and methods are described for the discrimination of particles using sedimentation field-flow fractionation operating without the use of rotating seals. Multiple lines of fluid and electrical communication are provided through a centrifugation unit comprising a fishhook-shaped umbilical conduit traveling from a stationary frame through a rotating guide frame to the separation channel. Twisting and tangling of the umbilical conduit enclosed communication lines are prevented by rotating the guide frame and separation channel in the same direction about an axis at an angular velocity ratio of 1:2. The design eliminates maintenance problems associated with rotating seals, simplifies channel installation and adjustment, and enables the use of multiple channels and the simultaneous application of multiple modes of field-flow fractionation either in concert or in a two-dimensional format. The design also enables the injector and/or detector to be mounted contiguously with the separation channel on the centrifugal rotor.

Disclosed herein is an apparatus for the separation of proteins, comprising a capillary isoelectric focusing unit (2) for primarily separating protein samples on the basis of pi; and a hollow fiber flow field flow fractionation unit (4), connected to one side of the capillary isoelectric focusing unit (2), for secondarily separating the protein samples. The apparatus allows proteins to be separated on the basis of pi and molecular weight without denaturation and can further be applied for the identification of proteins in conjunction with nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry after enzymatic digestion of the protein fractions.

Methods, devices, and systems for separating disparate liquid-suspended particles in a flow channel using dielectrophoresis induced by concave-shaped electrodes and field-flow fractionation.

The present invention relates to an apparatus for field-flow fractionation and to a method for separating samples by means of field-flow fractionation using this apparatus. The apparatuses of the invention comprise one or more reservoirs, a pump, a first flow volume splitting device, two valves for flow control, an injector, a separation channel having a first connector at a first end and a second connector at a second end or an AF4 separation channel having a first connector at a first end, a second connector at a second end and a third connector between the first and the second ends, optionally a second flow volume splitting device, a back-pressure element, one or more detector(s), a flow volume control device and one or more waste container(s). The apparatuses of the invention are characterized in that they comprise a valve for flow control in a first flow path and a second flow path which connect the pump to the first or the second or the third connector of the separation channel and that these valves are switched alternately in a controllable time ratio.

The invention relates to a device for determining a nanometer material through hollow fiber field-flow fractionation. The device comprises a separation channel which is a hollow fiber membrane of regenerated cellulose, polysulfone, polyether sulfone or polyacrylonitrile, wherein the molecular weight cut-off of the hollow fiber membrane is 30kDa; an injection pump is connected with the separation channel and used for providing a radial external field; a manual microsyringe feeds the sample into a flow path so that the sample enters the separation channel; the separation channel is connected with an ultraviolet detector for online detection to the nanometer material; and a moving phase is transported into the separation channel for elution through two plunger pumps respectively. The device has the advantages of low operating cost, simplicity in operation, good reproducibility and the like, and can be applied to separation and determination of other metal nano materials, metallic oxide nano materials, quantum dots, fullerene and other typical artificial nanometer materials.

Provided is a multi-channel apparatus for non-gel based two-dimensional protein separation. One or more flat channels are arranged in parallel and have an isoelectric focusing section for primarily separating proteins from protein samples according to isoelectric point (pI) and a flow field-flow fractionation section for secondarily separating the primarily separated proteins according to molecular weight, thereby making it possible to simultaneously separate the proteins in multiple channels, to increase a protein separation speed, and to overcome limitation to sample injection due to an increase in channel volume. The apparatus can separate the proteins according to pI and molecular weight, be safe from denaturation of the protein in the process of protein separation, automatically remove an ampholyte used for pI-based separation, and separately detecting the separated proteins to identify the proteins using nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS).

The invention relates to a manufacturing method for separating chips by a polymer field-flow and belongs to a new method and a new manufacturing technology of a biology separation filed. The chip is manufactured by the polymer through the technology of hot die forging and thermal bonding. The method comprises the following processes: (1) the manufacturing of the hot die template: the template having the same outer shape size with the separating channel is cut out form the metal plate. The size refers to the data as follows: the length is 300-600mm; the width is 20-40mm; the thickness is 0.5-2mm. The upper and lower bottom surface of the template are carried out a polishing process; (2) After the complete is heated on a hot press until softening, the outer shape of the separating channel is pressed out from the plate using the processed template; (3) the covering plate is carried out a thermal bonding using the coverslip and substrate and then bands out the chip. The invention solves the problems of single-use chip in a biology separating field, a medicine screening, a food and commodity inspection as well as an environment detection analysis. Compared with the traditional technology, the invention has the advantages of simple process and low manufacturing cost, as well as providing a precondition for the continuous production.

The invention provides a method for detecting content and a structure of resistant starch of a potato on the basis of field-flow fractionation technology. The method includes: a, hydrolyzing non-resistant starch of the potato; b, dissolving the resistant starch of the potato; c, measuring the content and the structure of the resistant starch of the potato by field-flow fractionation; d, calculating the content of the resistant starch of the potato. A multi-angle laser light scattering detector and a differential refraction detector are combined with asymmetric field-flow fractionation to detect the content of the resistant starch of the potato, the whole detection process is short and only lasts for 4 hours, and a turning radius and molecular weight distribution of the resistant starch canbe provided at the same time; the method is low in cost since an aqueous solution of 50 mM NaNO3+3 mM NaN3 is adopted as a flowing phase; the method has remarkable advantages as compared with a present universal AOAC (Association of Official Analytical Chemists) resistant starch detection method.

Provided are a natural rubber which maintains processability and is excellent in a breaking resistance and a wear resistance, a rubber composition containing the above natural rubber, and a tire prepared by using the same. The natural rubber of the present invention is obtained by gelatinizing or multi-coupling a natural rubber latex or a natural rubber and comprises 15 % by mass or more of a high molecular weight component, P1, having a molecular weight of 5,000,000 to 50,000,000 and 40 % by mass or less of an ultrahigh molecular weight component, P2, having a molecular weight of exceeding 50,000,000, and the relation between mass% of P1 and mass% of P2 is 1.5 × mass% of P1 ‰¥ mass% of P2, each measured by the following measuring method, wherein a measuring method for a rubber molecular weight is measured by means of a field flow fractionation equipment with a multi-angle light scattering detector for a soluble part of a centrifuged rubber solution at a centrifugal acceleration of 10,000 to 1,000,000 G.

The invention provides a method for separating and detecting serum lipoprotein. The method comprises the following steps of mixing a serum sample with a buffer solution, preparing a serum sample diluent, adding an organic solvent solution of Sudan black B into the serum sample diluent, oscillating in a constant-temperature shaker for not less than 3 hours in order to obtain a dyed serum sample diluent, and separating high-density lipoprotein and low-density lipoprotein in the dyed serum sample diluent by adopting asymmetric field-flow fractionation in combination with an ultraviolet visible light detector and detecting particle size distribution of the high-density lipoprotein and the low-density lipoprotein. The method disclosed by the invention is easy to operate and short in analysis time; the lipoprotein in the serum can be qualitatively detected, and the particle size distribution of the high-density lipoprotein and the low-density lipoprotein can be accurately quantitatively analyzed; the interference of free protein in the serum sample on lipoprotein separation is avoided; the crosslinking of a lipoprotein sample and a filter membrane is reduced; and the method has a wide application prospect.