University of Texas System

Dionex Corporation

The Dow Chemical Company

Texas Tech University System

Global Fia, Inc.

University of California

Kumamoto University

Bioarray Solutions Ltd.

World Precision Instruments, Inc.

Purnendu K Dasgupta

Kannan Srinivasan

Yongjing Chen

Weixiong Huang

Bingcheng Yang

Aditya Narayan Das

Charles Phillip Shelor

Hongzhu Liao

Masaki Takeuchi

Kazimierz Surowiec

Bikash Chouhan

Bao Li-Yuan

Christopher A Pohl

Matthew D Brenner

Su Yi Liu

Gerry R Boss

John R Stillian

S M Rahmat Ullah

Vijay Sharma

Shaorong Liu

Akinde F Kadjo

Keith A Friedman

Jordan Mitchell Berg

Joseph Ray

Ellis L Loree

Brian N Stamos

Kavin J Morris

Shin-Ichi Ohira

Jianzhong Li

Charles Philip Shelor

Kei Toda

Douglas L Strong

William Curt Blackledge

A device for ion chromatography comprises a tube with an inlet opening and an outlet opening and an inner diameter from about 40 microns to about 10 microns. There is an aperture through one side of the tube into a lumen of the tube. At least a portion of the inner surface of the tube has a first charge. An ion exchange barrier covers the aperture on an outside surface of the tube. The inner surface of the tube, from the inlet opening to the aperture, is coated with ion exchange particles having a diameter ranging from about 30 nm to about 200 nm. The ion exchange particles have a second charge opposite the first charge. The inner surface of the tube, from the outlet opening to the aperture, is not coated with ion exchange particles.

On-line suppressor

A permeative amine/acid introduction device (PAID) is placed after a conventional KOH eluent suppressed conductometric anion chromatography (SCAC) system. The PAID converts the suppressed eluites from the acid form to the corresponding salt. For example, when the analytes are acids, they are converted to the corresponding ammonium salt (NRH+HX&#x2192;NRH+X) and allows very weak acids HX (pK&#x2265;7.0) that cannot normally be detected by SCAC to be measured by a second conductivity detector following the PAID. Permeative reagent introduction is dilutionless, can be operated without pumps and provides good mixing with low band dispersion (as small as 30 &#x3bc;L). An exemplary amine is diethylamine (DEA), which was chosen as the amine source due to its low pKvalue (pK3.0), high vapor pressure, and low toxicity and low odor.

Permeative amine or acid introduction for very weak acid detection in ion chromatography

Buffer generators are described based on electrodialytic devices. The methods of using these devices can generate buffers for diverse applications, including separations, e.g., HPLC and ion chromatography. Also provided are chromatographic devices including the buffer generators, generally located upstream from a chromatography column, sample injector valve or both.

Electrolytic buffer generator

Open tubular capillary columns for liquid and ion chromatography, based upon an ionically impermeable polyolefin capillary having a bore with a sulfonate-group- or amine-group-functionalized internal surface. The capillary columns may include a coating of ion exchanging nanoparticles electrostatically bound to the functionalized internal surface. The capillary columns may be made by exposing the interior surface to a sulfonating reagent comprising chlorosulfonic acid (ClSOH), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25&#xb0; C. The interior surface may be subsequently exposed to an asymmetrical diamine to form a sulfonic mid-linkage to the diamine, i.e., to form a sulfonamide-linked, amine-group-functionalized internal surface. The coating may be provided by subsequently exposing the interior surface to an aqueous suspension of ion exchanging nanoparticles to electrostatically bond the ion exchanging nanoparticles to the functionalized internal surface.

Functionalized polyolefin capillaries for open tubular ion chromatography

A cartridge comprises a housing; a sample mixing compartment disposed within the housing, the sample mixing compartment comprising: an activation pouch, and a sample collection region; and a gas transporter tube having a first end and a second end, the tube being disposed within the housing adjacent to the sample mixing compartment, wherein the sample mixing compartment is partially defined by a moveable door of the housing, the moveable door providing access to the sample mixing compartment when the door is in an open position and preventing access to the sample mixing compartment when the door is in a closed position; and wherein the door is configured to release contents of the activation pouch upon movement from the open position to the closed position.

Devices and methods for detecting analytes

Ion chromatography system and methods utilizing a weak acid or weak base extraction device

A photothermal absorbance detection apparatus comprises a flow cell comprising a first temperature responsive device on an input side, a second temperature responsive device on an output side, and a detection region between the first temperature responsive device and the second temperature responsive device; and a light-emitting device positioned proximate to the detection region and configured to transmit electromagnetic radiation towards the detection region; wherein the first temperature responsive device and the second temperature responsive device together measure a change in temperature of a fluid passing through the detection region.

Photothermal absorbance measurement in a flow system

Analyte detecting device

Systems, methods and devices are taught for providing analytical methods for peak-shaped responses separated in time or space, including quantitation of chromatographic peaks based on a width measurement of a peak trace at a selected height as a quantitation element. Methods of treating a peak trace as a composition of exponential functions representing a leading and a trailing end are included. Methods that facilitate the detection of impurities in peak trace outputs are also included.

Systems, methods and devices for width-based analysis of peak traces

An electrodialytic device for ion chromatography, including aspects functioning as an eluent suppressor device and aspects functioning as an eluent generator device. In general, the device includes a monolithic block of ionomeric polymer material having (1) a first channel with an inlet port, an outlet port, and an active length of exposed polymer material disposed therebetween, (2) a second channel having an inlet port, an outlet port, and an active length of exposed polymer material disposed therebetween, (3) a first and second at-least-partially exposed electrodes positioned in electrical communication with the second channel, with the second electrode disposed, at least in part, across the second channel from the first electrode. A current flowing between the electrodes will drive an electrodialytic migration of ions between the active lengths, from an eluent stream in the case of a suppression device or into an eluent stream in the case of a generator device.

Electrodialytic capillary suppressor for suppressed conductometric ion chromatography

A system for increasing light throughput in cavity enhanced spectrometry, and a model for cavity enhanced absorption measurements are presented. The cavity has an entrance mirror, an opposed exit mirror and a detector positioned adjacent the exit mirror. An input aperture is defined in the entrance mirror to allow light from a source to enter the cavity. The input aperture improves light throughput without significant departure from the theoretically predicted amplification of absorbance. This results in improvement of detection limits, even with mirrors of modest reflectivity and inexpensive detectors.

Cavity enhancement methods, systems and devices, and methods of measuring same

There is provided a system for performing a chromatographic separation of an analyte, methods of using the system to separate at least one component of an analyte and an eluent generator of use in the system. An exemplary system comprises: (a) an eluent generator comprising: (i) a housing configured to be pressurizable by gas, comprising an annular void defined by the housing, and a gas inlet for the gas and a gas outlet for the gas in fluid communication with the annular void; (ii) a membrane permeable to the gas defining an eluent flow channel disposed within the annular void, the eluent flow channel having an eluent precursor fluid inlet and an eluent outlet; (iii) a source of gas in fluidic communication with the gas inlet; (iv) a source of the eluent precursor fluid; and (b) a chromatography column disposed downstream of and in fluidic communication with the eluent outlet.

Volatile eluent preparation

An electrodialytic buffer generator is described. The buffer generator may include a central buffer-generating channel having an inlet and outlet, a second chamber, and a third chamber. The buffer-generating channel, the second chamber, and the third chamber may each include an electrode. The buffer generator may also include a first ion exchange barrier and a second ion exchange barrier. The first ion exchange barrier can be disposed between the second chamber and the buffer-generating channel. The second ion exchange barrier can be disposed between the third chamber and the buffer-generating channel.

Three-electrode buffer generator and method

In one embodiment, a cavity-enhanced absorption spectroscopy system includes a cavity-enhanced absorbance cell in which a liquid sample can be provided for purposes of evaluation, the absorbance cell having diffusely reflective inner surfaces, a light source configured to emit light into the liquid sample within the absorbance cell, and a light detector configured to capture the light after it has passed through the liquid sample.

Systems and methods for performing cavity-enhanced absorption spectroscopy

Growing community of inventors

Arlington, TX, United States of America

Purnendu K Dasgupta