The present invention relates to an ion exchange fiber including: a core fiber; and an ion exchange layer that is disposed at a vicinity of the core fiber and includes a crosslinked polymer compound having an ion exchange group, in which, in a cross section perpendicular to a longitudinal direction of the ion exchange fiber, an area of the ion exchange layer occupies 50% or more and 90% or less of a total cross sectional area, and the ion exchange fiber has a swelling ratio of 50% or less.

The present disclosure relates to an ion exchange process, as well as a process and system for detecting nitrates, which employ a class of dopants comprising at least two functional groups capable of simultaneous convergent hydrogen bonding with a nitrate ion. In an aspect, the present disclosure provides an ion exchange process for forming a negatively charged nitrate-dopant ion analyte for analysis by a spectrometry analysis instrument, comprising: providing a gas comprising a dopant in both neutral and ionized forms; contacting a nitrate-containing sample with the gas comprising the dopant and thereby desorbing a nitrate ion from the sample to form a negatively charged nitrate-dopant ion analyte and replacing the desorbed nitrate ion with a negatively charged ionized dopant molecule; wherein the dopant is an organic compound comprising two or more carbon atoms and two or more functional groups capable of simultaneous convergent hydrogen bonding with a nitrate ion; or the dopant is an organic compound comprising at least two carbon atoms and only a single functional group capable of hydrogen bonding with a nitrate ion, which group is a COOH functional group, and where the carbon atom of the COOH functional group is bonded directly to another carbonyl group; and with the proviso that the dopant is not lactic acid, a lactic acid salt or a compound that forms lactate ions upon ionization.

The present disclosure relates to an ion exchange process, as well as a process and system for detecting nitrates, which employ a class of dopants comprising at least two functional groups capable of simultaneous convergent hydrogen bonding with a nitrate ion. In an aspect, the present disclosure provides an ion exchange process for forming a negatively charged nitrate-dopant ion analyte for analysis by a spectrometry analysis instrument, comprising: providing a gas comprising a dopant in both neutral and ionized forms; contacting a nitrate-containing sample with the gas comprising the dopant and thereby desorbing a nitrate ion from the sample to form a negatively charged nitrate-dopant ion analyte and replacing the desorbed nitrate ion with a negatively charged ionized dopant molecule; wherein the dopant is an organic compound comprising two or more carbon atoms and two or more functional groups capable of simultaneous convergent hydrogen bonding with a nitrate ion; or the dopant is an organic compound comprising at least two carbon atoms and only a single functional group capable of hydrogen bonding with a nitrate ion, which group is a COOH functional group, and where the carbon atom of the COOH functional group is bonded directly to another carbonyl group; and with the proviso that the dopant is not lactic acid, a lactic acid salt or a compound that forms lactate ions upon ionization.

Embodiments of the present disclosure provide for composites, methods of making composites, methods of removing a metal from a fluid, and the like.

Embodiments of the present disclosure provide for composites, methods of making composites, methods of removing a metal from a fluid, and the like.

A filter includes a porous molding, the porous molding being a sintered product of mixed powder containing dry gel powder including an ion exchange resin and thermoplastic resin powder, or a swelled body of the sintered product. When water having an electric resistivity value of 18 M?.Math.cm or more is allowed to pass through a space velocity of 1200 hr?1, the electric resistivity value of water after passage is 15 M?.Math.cm or more. To provide a filter that can efficiently remove metal ions in a solution to be treated, and easily acquire a solution having an extremely low content of metal ions.

A filter includes a porous molding, the porous molding being a sintered product of mixed powder containing dry gel powder including an ion exchange resin and thermoplastic resin powder, or a swelled body of the sintered product. When water having an electric resistivity value of 18 M?.Math.cm or more is allowed to pass through a space velocity of 1200 hr?1, the electric resistivity value of water after passage is 15 M?.Math.cm or more. To provide a filter that can efficiently remove metal ions in a solution to be treated, and easily acquire a solution having an extremely low content of metal ions.

Aminomethylated bead polymers for use as ion exchangers, especially as anion exchangers, or for the preparation of chelate resins, are prepared in the presence of 1,3-dichloropropane as solvent and swelling agent.

Aminomethylated bead polymers for use as ion exchangers, especially as anion exchangers, or for the preparation of chelate resins, are prepared in the presence of 1,3-dichloropropane as solvent and swelling agent.

A method of removing colloidal cobalt from an aqueous composition comprising bringing the aqueous composition into contact with a vinyl aromatic resin, wherein the vinyl aromatic resin comprises benzyl alcohol groups, benzyl ether groups, and methylene bridge groups, wherein the vinyl aromatic resin has a chlorine content, by weight based on the weight of resin, of 10,000 ppm or less.