Abstract: Apparatus for accurately metering liquid flow based on the injection of a brief heat pulse into the flowing stream, e.g., via a miniature thermistor, and detection of an electronic time derivative of temperature downstream with, e.g., a second microprobe thermistor. This detection triggers a subsequent heat pulse and the cycle repeats, wth pulse total corresponding to elapsed liquid throughput, and pulse frequency to flow rate.

Abstract: A permselective ion-exchange membrane, preferably comprising hollow fiber(s) immersed within a regenerant, is used to selectively neutralize or suppress the conductivity of electrolyte in a stream of eluent also containing chromatographically separated ions. The invention particularly specifies a chromatographic separating column useful with an electrolyte eluent solution to separate ionic species by elution chromatography, wherein the effluent of the separator column is treated by the described membrane to suppress the conductivity of the electrolyte but not that of the separated ions.

Abstract: An improved technique for the measurement of ions in solution where the ions of interest are chromatographically displaced from an ion exchange column by an eluting ion which is or is made light-absorbing, and where the eluted sample ions, which are transparent (at the monitored wavelength), are detected and quantified from the decrements they cause in effluent absorbance as revealed by photometric monitoring.

Abstract: Colloidal particles are fractionated by size and dissolved polymers are fractionated by molecular weight by passing a polar solvent dispersion containing one or both through a bed of surface-bonded particles wherein the particles consist of a nonswellable inert core with a polar solvent-swellable surface coating of bonded organic polymer. The core can be either an insoluble cross-linked organic polymer gel or an inorganic solid such as silica or alumina.

Abstract: An ion exchange composition comprising an insoluble substrate of a synthetic resin having ion exchanging sites at least on its available surface; and a finely divided, insoluble material comprising synthetic resin particles of from about 0.1 to about 5 microns median diameter (with respect to volume) having, at least on their outer surfaces, ion exchanging sites which attract the ion exchanging sites of the substrate, irreversibly attached as a monolayer to the available surface of the substrate. The composition is used for removal and separatin of ions, and is especially useful in liquid ion exchange chromatography.

Abstract: An ion exchange composition comprising an insoluble substrate of a synthetic resin having ion exchanging sites at least on its available surface; and a finely divided, insoluble material comprising synthetic resin particles of from about 0.1 to about 5 microns median diameter (with respect to volume) having, at least on their outer surfaces, ion exchanging sites which attract the ion exchanging sites of the substrate, irreversibly attached as a monolayer to the available surface of the substrate. The composition is used for removal and separation of ions, and is especially useful in liquid ion exchange chromatography.

Abstract: Apparatus and method for chromatographic quantitative analysis of a solution containing a plurality of species of cations. A sample of the solution is added to a first ion exchange resin bed containing cation exchange resin and eluted therefrom with a solution of developing reagent consisting of either AgNO.sub.3 or BaCl.sub.2, chromatographic separation of the cationic species being achieved as elution proceeds. The effluent from the first ion exchange resin bed is passed through a second ion exchange resin bed containing anion exchange resin in a form appropriate to the precipitation of whichever metal ion is provided by the developing reagent, i.e., chloride or sulfate forms. As elution proceeds the cations exit from the second ion exchange bed without destroying the ionic separation achieved in the first ion exchange resin bed. Each separated cationic species is quantitatively sensed by a detector such as a conductivity cell on exiting from the second ion exchange resin bed.

Abstract: A process for high performance, cation-exchange chromatography employing a cation-exchange composition comprising synthetic resin particles of about 5 to about 200 microns particle size, said synthetic resin particles being cross-linked to from about 0.25 to about 5% and surface-sulfonated to a calculated depth of about 100 to about 300 Angstroms is disclosed.