Dionex Corporation

Government of the United States of America, As Represented by the Secretary of Commerce

The United States of America

Archava Siriraks

John M Riviello

Christopher A Pohl

Yan Liu

Nebojsa Avdalovic

Howard M Kingston, Jr

Rosanne Williamson Slingsby

Harpreet S Dhillon

A liquid chromatographic system is provided including catalytically combining hydrogen and oxygen gases in the chromatography eluent stream in a catalytic gas elimination chamber, to form water and thereby reduce the gas content in the eluent stream. Also, a liquid ion chromatographic system in which the effluent from the detector is recycled to a membrane suppressor and then is mixed with a source of eluent for recycle to the chromatographic column.

Ion chromatography system using catalytic gas elimination

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 flow through a first cation exchange resin bed having precipitable exchangeable polyvalent ions (e.g. barium ions). Displacing polyvalent cation (e.g. calcium) displaces the exchangeable polyvalent ion from the cation exchange resin into the liquid sample at sufficient concentration to cause the precipitable anion and exchangeable cation to form a precipitate which remains in the resin bed and is thus is removed from the sample stream. Then the anions of interest in the soluble portion of the liquid sample stream are separated and detected. The invention is also applicable to the removal of precipitable cations (e.g. barium ions) by reversing the roles of the anions and cations.

Method for precipitation of insoluble salts in divalent ion-form

A system is provided for the detection of transition elements and/or rare earth elements in an aqueous sample which also contains high concentrations of alkali and alkaline earth metals. The system is effective for determination of transition elements and/or rare earth elements in sea water, industrial waste streams, biological fluids and biological issue samples.

System for detecting transition and rare earth elements in a matrix

A method for the detection of trace transition elements and rare earth elements in a sample also containing alkali metals or alkaline earth elements. The sample is flowed through a chelator column which retains the transition elements and rare earth elements. Then a first eluent (e.g. ammonium acetate) is passed through the column to strip the alkali and alkaline earth metals retained on the column. Then a second eluent (e.g. a strong acid) is passed through the chelator column to remove the transition elements in a chelator effluent which flows through an ion exchange resin concentrator to retain only the transition elements and rare earth elements. Then, a chelator complexing agent (e.g. pyridine-2,6 dicarboxylic acid or an oxalate) flows through the concentrator column to remove the transition elements and rare earth elements.

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Bangkok, Thailand

Archava Siriraks