Dialysis cell for sample preparation for a chemical analysis method
Inventors
LÄUBLI, Markus • Frenzel, Wolfgang • MARKEVICIUTE, Inga • Abderhalden, Daniel
Assignees
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Publication Number
US-11712660-B2
Publication Date
2023-08-01
Expiration Date
Abstract
The invention relates to a dialysis cell for sample preparation for a chemical analysis method, in particular for ion chromatography. The dialysis cell comprises a donor channel and an acceptor channel extending parallel thereto. The donor channel and the acceptor channel are separated from each other by a selectively permeable dialysis membrane. In particular, an analyte that is dissolved in a donor solution in the donor channel can enter through the dialysis membrane into the acceptor solution in the acceptor channel. The acceptor channel has at least in some sections a volume that is smaller than the volume of the donor channel extending parallel thereto. Acceptor and donor channels are formed from half-cells, between which the dialysis membrane is arranged, wherein the donor channel and the acceptor channel are designed in each case as a recess in a contact surface of one of the half-cells with the dialysis membrane.
Core Innovation
The disclosed invention relates to a dialysis cell for sample preparation for a chromatographic method, including ion chromatography. The dialysis cell comprises a donor channel and a parallel acceptor channel separated by a selectively permeable dialysis membrane, and the donor channel and the acceptor channel are implemented as spiral or meandering channels formed as indentations in a contact surface of two half-cells with the dialysis membrane arranged between the half-cells.
The acceptor channel has, on its entire length, a volume VA that is smaller than a parallelly running volume VD of the donor channel. The acceptor channel volume is formed by recess geometry in the contact surface and is maintained in the acceptor direction by at least one support element, which spaces the dialysis membrane from the side of the acceptor channel that faces away from the dialysis membrane.
The asymmetrical acceptor and donor volume arrangement is linked to reduced equilibration time tA and reduced dialysis time tD, with resulting higher sample throughput. The document further states reduced matrix impurity breakthrough, reduced sample volume, and improved recovery rate and breakthrough behavior for ions such as chloride, sulfate, and nitrate, together with reduced breakthrough of matrix impurities described as lignin and protein-related impurities.
Claims Coverage
The independent claim set includes 1 independent claim with multiple dependent refinements. The coverage centers on an asymmetrical donor and acceptor volume dialysis cell with spiral or meandering parallel channels, a two-half-cell membrane arrangement using indentations, and a support element that spaces the membrane in the acceptor channel.
Dialysis cell with parallel donor and acceptor channels separated by a selectively permeable membrane
A dialysis cell for sample preparation for a chromatographic method comprising a donor channel and a parallelly running acceptor channel, wherein the donor and acceptor channels are separated by a selectively permeable dialysis membrane.
Asymmetrical acceptor and donor channel volumes
The acceptor channel has, on its entire length, a volume VA which is smaller than a parallelly running volume VD of the donor channel.
Spiral or meandering channel geometry in the donor and acceptor
The donor channel and the acceptor channel are spiral or meandering.
Two half-cells with membrane arranged between indentations in a contact surface
The dialysis cell comprises two half-cells, between which the dialysis membrane is arranged, wherein the donor channel and the acceptor channel are formed as, in each case, an indentation in a contact surface of one of the half-cells with the dialysis membrane.
Support element spacing the membrane from the acceptor-channel side
At least one support element is formed in the acceptor channel, which support element spaces the dialysis membrane from the side of the acceptor channel that faces away from the dialysis membrane.
Acceptorside channel volume per unit length constraint
An acceptor channel length section with volume per unit length VA/L from 0.005 mm3/mm to 2.0 mm3/mm.
Donorside channel volume per unit length constraint
A donor channel length section with volume per unit length VD/L from 0.25 mm3/mm to 3.5 mm3/mm.
Dialysis membrane pore size constraint
A dialysis membrane whose pore size is from 0.01 cm to 1.0 cm.
Dialysis membrane material selected from a listed set
A dialysis membrane consisting of a material selected from cellulose acetate, cellulose nitrate, polyvinylidene fluoride, polycarbonate, mixed cellulose ester, cellulose hydrate, regenerated cellulose, or polyamide.
Acceptorside cross-section geometry constraint
An acceptor channel cross-section that is at least sectionally a rectangle with rounded corners on the side away from the dialysis membrane, with a width-to-depth ratio from 80:1 to 10:1.
Overall, the claim coverage focuses on a dialysis cell with parallel spiral or meandering donor and acceptor channels separated by a selectively permeable dialysis membrane arranged between two half-cells via indentations, combined with an acceptor-channel volume VA smaller than donor-channel volume VD. The membrane spacing is supported by at least one support element in the acceptor channel, and dependent claims further constrain channel volume per unit length, membrane pore size, membrane material, and acceptor cross-sectional geometry.
Stated Advantages
Reduced equilibration time tA.
Shorter dialysis time tD.
Higher sample throughput.
Reduced matrix impurity breakthrough.
Reduced sample volume.
Improved recovery rate and breakthrough behavior for ions such as chloride, sulfate, and nitrate, and reduced breakthrough of matrix impurities described as lignin and protein-related impurities.
Documented Applications
Sample preparation for a chromatographic method, including ion chromatography.
Integration into stopped-flow inline analytical systems for sample analysis in which pumping is used to avoid pressure gradients.
Water sample analysis using the dialysis cell configuration.
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