Abstract:
Apparatus for analysis of ionic species in an aqueous liquid stream comprising: (a) a chromatographic separator (10) including medium for separating said ionic species and having an inlet and outlet (b) a source of an aqueous eluent solution comprising electrolyte in fluid communication with said chromatographic separator; (c) a membrane suppressor (12) comprising a chromatography affluent flow channel separated by an ion exchange membrane from a regenerant flow channel having an inlet and an outlet; (d) a container (26) including an inlet and an outlet, said container outlet being in fluid communication with said regenerant flow channel; (e) a regenerant liquid reservoir (28) in said container of a different chemical composition than said chromatography affluent; (f) a detector (16) for detecting ionic species in fluid communication with said chromatography effluent flow channel; and (g) a recycle conduit (30) for the flow of effluent from said detector to said container inlet.
Abstract:
In an extensive Matched Ion Polynucleotide Chromatography (MIPC) system and method, and the computer programs or software associated therewith, the system provides automated options for sample selection, mobile phase gradient selection and control, column and mobile phase temperature control, and fragment collection for a wide variety of MIPC separation processes. MIPC separation processes can be applied to effect size-based separation of DNA fragments, mutation detection, DNA fragment purification, PCR process monitoring and other novel processes. This invention is directed to the system and software which automates many of these procedures, facilitating use of the system to achieve complex separation methods. In one embodiment of the invention, a user specifies a size range of double stranded DNA fragment(s) in a mixture, the software calculates a solvent gradient to elute the fragment(s), and the system performs the chromatographic separation using the calculated gradient. In an embodiment useful in DNA mutation detection, a user specifies the base sequence of a wild type DNA molecule, the software calculates a temperature for partially denaturing heteroduplex and homoduplex molecules of the DNA in a mixture, the software calculates a solvent gradient to elute the fragments, and the system performs the chromatographic separation using the calculated gradient and temperature.
Abstract:
This invention provides a rapid, high throughput method for simultaneously measuring biologically significant physicochemical characteristics for multiple compounds. More specifically, this invention is directed to the measurement and use of binding affinities of multiple compounds with a surface under controlled conditions to calculate biologically significant physicochemical values.
Abstract:
An electrolytic suppressor (22) including (a) a suppressor bed (26) of ion exchange resin, (b) an electrode chamber (44) adjacent the suppressor, (c) a first electrode (42) in the electrode chamber, (d) a barrier (40) separating the suppressor bed from the first electrode chamber preventing significant liquid flow but permitting transport of ions only of the same charge as the suppressor bed resin, (e) a second electrode (36) in electrical communication with the resin bed, and (f) a recycle conduit (30, 32, 34, 38, 48) between the suppressor outlet port and said electrode chamber. The second electrode may be in contact with the ion exchange resin in the suppressor or located in second electrode chamber. For anion analysis, the method of using the apparatus includes: (a) flowing an aqueous liquid sample stream containing anions to be detected and cation hydroxide through the separator bed, (b) flowing the aqueous effluent from the separator bed through the flow-through suppressor, (c) flowing the effluent liquid from the suppressor past a detector, (d) recycling said liquid effluent from the detector through a cathode chamber proximate to the suppressor bed and separated by the first barrier, and (e) applying an electrical potential between the cathode and the anode. Water is electrolyzed at the anode to cause cations on the cation exchange resin to electromigrate toward the barrier and to be transported across the barrier toward the cathode while water in the cathode chamber is electrolyzed to generate hydroxide ions which combine with the transported cations to form cation hydroxide in the cathode chamber.
Abstract:
Method and apparatus for generating an acid or base, e.g., for chromatographic analysis of ions. For generating a base, a cation source, such as a salt, cation hydroxide or cation exchange resin, is provided in a cation reservoir (10) separated from a base generation chamber (12) by a permselective barrier (14). An aqueous stream (21) flows through the base generation chamber (12) containing a cation exchange material (19). An electric potential is applied between an anode (16) in the cation source reservoir (10) and a cathode (18) in the base generation chamber (12) to electrolytically generate hydroxide ions and cause cations in the reservoir (10) to electromigrate through the barrier (14) toward the cathode (18) to combine with the migrated cations to form cation hydroxide, which flows from the base generation chamber (12).
Abstract:
A method and apparatus using suppression of eluents for the analysis of anions or cations in ion chromatography. The invention relates to the intermittent use of the electric field during electrochemical suppression to minimize background noise during detection of the ionic species caused by the application of an electric field using an electrolytic membrane suppressor. Using this intermittent electrochemical suppression system allows the detection of the analyte in the absence of the electric field. The system finds particular benefit in reducing background noise created during electrochemical suppression, and in reducing the baseline interference when analyzing organic solvent-containing samples.
Abstract:
Selected polyvalent anions or cations are removed from a liquid sample stream as a pretreatment for the analysis of the liquid sample stream. A stream containing anions of interest, precipitable anions (e.g. sulfate ions) to be removed and an added displacing salt having a polyvalent cation flow through a cation exchange resin bed having precipitable exchangeable polyvalent ions (e.g. barium ions). The polyvalent cation (e.g. calcium) of the displacing salt exchanges with the cation of the resin, which reacts with the precipitable anion to form a precipitate which is retained in the bed. The anions of interest are subsequently separated and analyzed. The invention is also applicable to the removal of precipitable cations (e.g. barium ions) by reversing the roles of the anions and cations.
Abstract:
A method for identification and quantification of sulfonation by-products by ion chromatography. The method utilizes two eluants and preferably three eluants to identify and quantify the by-products on a single chromatographic run.
Abstract:
Methods and microcolumns (20) to determine a numerical percentage value as a diagnostic indicator of the blood sugar condition of a specific person. A whole blood sample (10) is lysed and a test sample thereof is placed on a microchromatographic column bed of ion exchange material particles (27). The column bed is characterized by having no cyanide therein. The column bed comprises an equilibrated suspension of particles selected from the class consisting of CarXH and CarYOH, where "Car" represents an inert substrate for carrying ionizable groups X- providing dissociated cations H+ and ionizable groups Y+ providing anions OH-. Fractions (31, 32) of various hemoglobin species in the test sample are preferentially eluted or desorbed from the column bed by buffer and wash solutions characterized by having no cyanide therein. Amounts of hemoglobin species in the eluate fractions are detected and measured by spectrometric (color) analysis (40). A mathematical computation using integer factors corresponding to amounts of various hemoglobin species produces the numerical percentage value.
Abstract:
The present invention provides modified von Willebrand Factor molecules, methods for their preparation and uses thereof. The invention further provides pharmaceutical compositions for treating coagulation disorders.