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.

Sample focusing method and device for field-flow fractionation techniques that lead to improved detection, improved separation resolution, and a compressed sample plug while permitting a more straightforward quantitation of peaks and reliable large volume injections. The method and device can be implemented in separations that are performed by a variety of field-flow fractionation techniques, including thermal FFF, electrical FFF, sedimentation FFF, gravitational FFF, dielectric FFF, photophoretic FFF, flow FFF, asymmetric flow FFF, and symmetric flow FFF. The sample focusing device can be integrally built into a separation channel or it can be manufactured as an attachable independent piece.

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 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.

The invention concerns a method and system for analyzing a liquid sample containing solid matter. The method comprises fractionating the sample according to particle sizes and / or masses of the solid matter so as to produce sample fractions, and measuring at least one physical or chemical property of at least one of said sample fractions. According to the invention the sample is conducted to a disintegration channel having one or more depressions, and a liquid flow having a non-constant temporal velocity profile is applied through the disintegration channel, in order to gradually take solid matter of the sample with the liquid flow from said one or more depressions for providing said sample fractions. The invention allows for efficient fractionation of samples, which cannot be fractionated using conventional field flow fractionation, for example.

A field flow fractionator to separate particles contained within an injected sample aliquot is described. As required, said fractionator may be used to capture, for subsequent removal, specific predefined classes of such particles. Based upon the cross flow or asymmetric flow field flow fractionators, the fractionator disclosed contains means to vary the applied transverse flows at a plurality of locations along the length of its separating channel. A plurality of separated compartments, each lying below a distinct and corresponding membrane supporting permeable frit segment, are provided individual means to control the localized flow through the membrane section thereabove. A corresponding concentric compartment implementation achieves the same type of compartmentalized cross flow when integrated with a hollow fiber fractionator.

The invention provides a method of determining particle size distribution of fine particles contained in metallic material. The method comprises: a step in which fine particles contained in a metallic material to be examined are isolated by extraction with a solution using a means of extraction for fine-particle isolation; a step in which the fine particles isolated by extraction are dispersed ina solvent to prepare a dispersion and the dispersion is separated into fine-particle dispersions having respective size ranges with a field-flow fractionation device; and a step in which the fine-particle dispersions having respective size ranges are irradiated with a laser light to determine the absolute value of the size of the fine particles of each dispersion from the angle dependence of the resultant reflected-light intensity, and the number density of the fine particles is determined from the reflected-light intensity.

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.

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).

This field flow fractionation device is provided with a flow path switching unit which switches and connects a second carrier fluid supply unit to one port among a second inlet port of an upper end-side separation cell, an inlet port of a lower end-side separation cell, or a second inlet port of a lower end-side separation cell. In addition, the field flow fractionation device is configured such that: when focusing is performed to generates a carrier fluid flow against the carrier fluid flow from the inlet port in the upper end-side separation cell, the second carrier fluid supply unit is connected to the second inlet port of the upper end-side separation cell, and when the focusing in the upper end-side separation cell is completed, the second carrier fluid supply unit is connected to theinlet port or the second inlet port of the lower end-side separation cell.

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.

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 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.

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.

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 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 a separation channel which, in addition to a first outlet for sample-containing solvent, comprises a second outlet for sample-free solvent, wherein the second outlet is arranged in a region of the separation channel from which sample-free solvent may be removed during elution and a flow volume control device is arranged downstream of the second outlet. They are characterized in that the flow volume control device is a mass flow controller.

A field flow fractionator to separate particles contained within an injected sample aliquot is described. As required, said fractionator may be used to capture, for subsequent removal, specific predefined classes of such particles. Based upon the cross flow or asymmetric flow field flow fractionators, the fractionator disclosed contains means to vary the applied transverse flows at a plurality of locations along the length of its separating channel. A plurality of separated compartments, each lying below a distinct and corresponding membrane supporting permeable frit segment, are provided individual means to control the localized flow through the membrane section thereabove. A corresponding concentric compartment implementation achieves the same type of compartmentalized cross flow when integrated with a hollow fiber fractionator.

Some embodiments of the methods and compositions provided herein include identifying and / or quantifying oligomeric species of surfactant protein-D (SP-D). Some embodiments include performing an asymmetric flow field-flow fractionation with multi-angle laser light scattering (AF4-MALLS) analysis on the SP-D.