Abstract:
An apparatus for measuring the light scattering properties of a sample in a liquid medium, wherein the liquid medium with the sample is illuminated by a laser beam in a measuring cell transversely to the direction of filling the liquid medium in the measuring cell or transversely to the flow direction of the liquid medium within the measuring cell, comprising a laser, a cylindrical measuring cell, a first inner aperture system, a second outer aperture system and at least two detectors, wherein the detectors are arranged outside of the second outer aperture system so that they collect the light scattered on the sample within set, different angle ranges, wherein the first inner aperture system and the second outer aperture system are formed and arranged circularly and concentrically around the axis of the measuring cell. Use of the apparatus and a method that makes use of the apparatus are also disclosed.
Abstract:
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.
Abstract:
An apparatus for measuring the light scattering properties of a sample in a liquid medium, wherein the liquid medium with the sample is illuminated by a laser beam in a measuring cell transversely to the direction of filling the liquid medium in the measuring cell or transversely to the flow direction of the liquid medium within the measuring cell, comprising a laser, a cylindrical measuring cell, a first inner aperture system, a second outer aperture system and at least two detectors, wherein the detectors are arranged outside of the second outer aperture system so that they collect the light scattered on the sample within set, different angle ranges, wherein the first inner aperture system and the second outer aperture system are formed and arranged circularly and concentrically around the axis of the measuring cell. Use of the apparatus and a method that makes use of the apparatus are also disclosed.
Abstract:
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.
Abstract:
The current invention relates to an apparatus for performing a centrifugal field-flow fractionation. In particular, in the apparatus according to the invention, radial rotary shaft seals are used for sealing the rotating parts of the shaft for carrying out the centrifugal field-flow fractionation and the stationary parts. Furthermore, a separate line is introduced for reducing the pressure differential across these seals. In such way, the driving force driving sample fluid across the seals is reduced, thereby reducing leakage.
Abstract:
The invention provides a method for measuring light scattered on a sample in a medium, in particular a fluid medium, that comprises the following steps: providing a rotatably arranged measuring cell with a substantially circular cross-section in a plane perpendicular to the axis of rotation for receiving the medium and the sample, rotating the measuring cell, preferably at least once by substantially 360°, about the axis of rotation, in particular by means of a drive, emitting a laser beam by means of a laser onto the sample located within the measuring cell in the plane perpendicular to the axis of rotation at different angles of rotation of the measuring cell, the measuring cell maintaining its position in the direction of the axis of rotation, detecting scattered light signals by means of at least two detectors arranged in a circle and concentrically to the center of rotation of the measuring cell and fixed within set, different angular ranges at different angles of rotation of the measuring cell, and determining a corrected signal value for each detector on the basis of the scattered light signals detected at different angles of rotation of the measuring cell for each detector. Furthermore, the invention provides an apparatus for measuring light scattered on a sample according to the method comprising a laser, a measuring cell and a detector.
Abstract:
The invention provides a method for measuring light scattered on a sample in a medium, in particular a fluid medium, that comprises the following steps: providing a rotatably arranged measuring cell with a substantially circular cross-section in a plane perpendicular to the axis of rotation for receiving the medium and the sample, rotating the measuring cell, preferably at least once by substantially 360°, about the axis of rotation, in particular by means of a drive, emitting a laser beam by means of a laser onto the sample located within the measuring cell in the plane perpendicular to the axis of rotation at different angles of rotation of the measuring cell, the measuring cell maintaining its position in the direction of the axis of rotation, detecting scattered light signals by means of at least two detectors arranged in a circle and concentrically to the centre of rotation of the measuring cell and fixed within set, different angular ranges at different angles of rotation of the measuring cell, and determining a corrected signal value for each detector on the basis of the scattered light signals detected at different angles of rotation of the measuring cell for each detector. Furthermore, the invention provides an apparatus for measuring light scattered on a sample according to the method comprising a laser, a measuring cell and a detector.