Abstract: 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 (NR2H+HX?NR2H2++X?) and allows very weak acids HX (pKa?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 ?L). An exemplary amine is diethylamine (DEA), which was chosen as the amine source due to its low pKb value (pKb 3.0), high vapor pressure, and low toxicity and low odor.

Abstract: 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.

Abstract: 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.

Abstract: 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 (ClSO3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25° 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.

Abstract: A flow meter comprises a capillary, a first and second fluid flow marker, and one or more sensors. The capillary has a longitudinally extending fluid receiving space, with a first end and a second end. The first and second fluid flow markers are immiscible and are positioned in the fluid receiving space. The one or more sensors are positioned along the capillary. A method for measuring flow rates comprises the steps of introducing a first liquid into a flow meter. That first liquid flows into the fluid receiving space at the first end of the capillary thereby displacing the first fluid flow marker and the second fluid flow marker towards the second end of the capillary. The interface between the first fluid flow marker and the second fluid flow marker is measured with one or more sensors to determine the flow rate of the first liquid.

Abstract: 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.

Abstract: 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 (NR2H+HX?NR2H2++X?) and allows very weak acids HX (pKa?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 ?L). An exemplary amine is diethylamine (DEA), which was chosen as the amine source due to its low pKb value (pKb 3.0), high vapor pressure, and low toxicity and low odor.

Abstract: A method of determining an identity of a first analyte in a sample is described that includes passing the first analyte through a chromatographic column and detecting a signal curve of the first analyte by a chromatographic detector, wherein the signal curve includes a peak profile of the first analyte. The peak profile is defined by a plurality of measured data points configured to plot onto a signal coordinate system. The method further includes normalizing the peak profile of the first analyte to form a normalized peak profile, wherein the normalized peak profile includes scaling the plurality of measured data points, and wherein the normalized peak profile is defined by a plurality of normalized data points configured to plot onto a normalized coordinate system, and comparing the normalized peak profile of the first analyte with a normalized peak profile of a second analyte.

Abstract: A method of converting longer path cell signal data to shorter path cell signal data comprising: obtaining a longer path absorbance signal tracing and a shorter path absorbance signal tracing for at least one analyte band under the same conditions; obtaining an approximate superimposable match between the longer path absorbance signal tracing and the shorter path absorbance signal tracing using an amplitude scaling factor and one or more parameters derived from a dispersion model that accounts for dispersion differences between a short cell and a long cell; and applying the dispersion model in reverse using the derived parameters to future longer path absorbance signal traces from the longer path cell signal data to generate the shorter path cell signal data.

Abstract: 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 (CISO3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25° 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.

Abstract: 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 (ClSO3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25° 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.

Abstract: 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 (NR2H+HX?NR2H2++X?) and allows very weak acids HX (pKa?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 ?L). An exemplary amine is diethylamine (DEA), which was chosen as the amine source due to its low pKb value (pKb 3.0), high vapor pressure, and low toxicity and low odor.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.