An ion suppressor includes ion exchange membranes between a pair of electrodes. Regeneration liquid channels are provided in the spaces between the electrodes and the ion exchange membranes, and an eluent channel is provided between the ion exchange membranes. In the space between the electrode and the eluent channel, an element that increases the resistance in the voltage application direction is disposed. For example, ion permeable membranes are disposed in contact with the ion exchange membrane, thereby increasing the resistance in the voltage application direction.

Methods are disclosed for producing highly purified recombinant human insulin (RHI) having a purity of 99.0% (w/w) or greater, a Total Impurity (not including the related substance desamido Asn.sup.A21-RHI, as specified by USP) of 0.8% (w/w) or less, and an impurity C of 0.1% (w/w) or less. Also disclosed are API compositions of highly purified RHI having a purity of 99.0% (w/w) or greater, a Total Impurity of 0.8% (w/w) or less, and an impurity C of 0.1% (w/w) or less.

Method for reducing concentration of iron ions in a trivalent chromium electroplating bath, including: (i) providing the trivalent chromium electroplating bath including trivalent chromium ions, and iron ions, (ii) subjecting at least a portion of the bath to air agitation, to obtain an air-agitated portion of the bath, (iii) contacting the air-agitated portion with an ion exchange resin, to obtain a resin-treated portion of the bath, and (iv) returning the resin-treated portion of the bath to the trivalent chromium electroplating bath,
provided that the bath provided in step (i) was or is utilized for electrodepositing chromium on a substrate applying a cathodic current density of 18 A/dm.sup.2 or more, after step (iii), iron ions in the resin-treated portion have a lower concentration than in the air-agitated portion, and after step (iv), iron ions in the bath have a concentration below 50 mg/L.

The present disclosure relates to multistep chromatographic methods for preparing extracellular vesicles (EVs). The methods were demonstrated to be effective in preparing highquality EVs in a large scale. The methods enable preparation of EVs for therapeutic and diagnostic applications, and isolation and/or sub-fractionation of EVs with desired properties for specific use.

The present invention relates to a method for the separation and purification of glycoforms with an ion exchange separation material with amino-acid based endgroups.

This present invention is directed to variable affinity chromatography apparatus and methods for using the same. In particular, the polarity of the stationary phase or the mobile phase is modulated using an external stimulus. Exemplary external stimulus that can be used in the invention include, but are not limited to, electric field, electromagnetic radiation including UV, Vis, and infrared wavelengths, as well other stimuli that are known to one skilled in the art. Generally, any external stimulation that changes the polarity of a stimulus responsive material can be used. One particular embodiment of the invention provides a chromatography apparatus comprising: (i) a chromatography column having a stationary-phase separation medium contained therein; (ii) an external stimulus generator operatively connected to said chromatography column; and (iii) a chromatography mobile-phase, wherein at least one of said stationary-phase separation medium and said chromatography mobile-phase comprises a stimulus responsive material that adopts a different configuration based on the absence or the presence of said external stimulus, wherein different configurations of said stimulus responsive material results in a different stationary or mobile phase affinity, and wherein said external stimulus is selected from the group consisting of electric field, electromagnetic radiation, and a combination thereof.

The present disclosure relates to an improved method for producing allulose and, more particularly, to a method for preparing a fructose-containing raw material solution by using raw sugar as a raw substrate used in the production process.

An apparatus, system, and method for removing impurities from a non-aqueous electrolyte used in an electrochemical cell. The apparatus includes a vessel having one or more chambers with an inlet and an outlet configured to allow the flow of the electrolyte through the one or more chambers; and an inorganic scavenging agent located within the one or more chambers. The inorganic scavenging agent includes one or more types of zeolite particles, at least one type of absorbent filler particles, or a combination of the zeolite and absorbent filler particles. The inorganic scavenging agent absorbs one or more of moisture, free transition metal ions, or hydrogen fluoride (HF) that is present as impurities in the non-aqueous electrolyte.

A method for strontium isotope analysis of picogram-level samples using highly sensitive silicotungstic acid emitter is presented by a thermal ionization mass spectrometry. The emitter has merits of extremely high sensitivity, low cost, simple operation, etc. It is an important innovation of the strontium isotope analysis of the picogram-level samples. Compared with a sample consumption of 1-50 ng of conventional emitter, the present invention only needs 30-200 pg to obtain satisfying measurement accuracy. The present invention greatly improves test sensitivity, and has broad application prospects in future.

The invention relates to methods for removal of low isoelectric point product-related impurities during cation exchange purification operations.