Provided is a method for producing purified acetic acid with a good hue. A method for producing purified acetic acid, including treating acetic acid having a poor hue with a synthetic adsorbent to obtain acetic acid with an improved hue. The acetic acid to be treated is, for example, acetic acid having an absorbance of 0.01 or greater at a wavelength of 430 nm. The acetic acid to be treated may be acetic acid recovered from an acetic acid-containing solution that is discharged in a cellulose acetate production process. The synthetic adsorbent may have a cation exchange group on a resin surface. The synthetic adsorbent may have a pore structure.

Provided is a method for producing purified acetic acid with a good hue. A method for producing purified acetic acid, including treating acetic acid having a poor hue with a synthetic adsorbent to obtain acetic acid with an improved hue. The acetic acid to be treated is, for example, acetic acid having an absorbance of 0.01 or greater at a wavelength of 430 nm. The acetic acid to be treated may be acetic acid recovered from an acetic acid-containing solution that is discharged in a cellulose acetate production process. The synthetic adsorbent may have a cation exchange group on a resin surface. The synthetic adsorbent may have a pore structure.

Compositions and methods are provided for producing crystalline forms of organic acids or salts or lactones thereof from an aqueous solution. More specifically, methods are provided for producing a crystalline form of a salt of mevalonic acid (also referred to as X-MVA) from an aqueous solution, comprising subjecting the aqueous solution comprising said X-MVA to a purification step to produce a purified solution and crystallizing said X-MVA from said purified solution by water solvent crystallization. Methods are also provided for producing mevalonolactone from an aqueous solution comprising X-MVA, comprising subjecting the aqueous solution comprising said X-MVA to cation exchange thereby converting said aqueous solution comprising X-MVA to an aqueous solution comprising mevalonolactone (MVL). Methods are also provided for producing mevalonolactone monohydrate crystals.

Method for lowering aldehyde content in a mixture comprising (i) diethylene glycol (DEG) and/or triethylene glycol (TEG) and (ii) aldehyde are disclosed. An ion exchange resin is soaked in monoethylene glycol. The mixture comprising 5 to 200 ppm aldehyde is then flowed to make contact with the soaked ion exchange resin to produce a product comprising DEG and/or TEG and less than 15 ppm aldehyde.

Method for lowering aldehyde content in a mixture comprising (i) diethylene glycol (DEG) and/or triethylene glycol (TEG) and (ii) aldehyde are disclosed. An ion exchange resin is soaked in monoethylene glycol. The mixture comprising 5 to 200 ppm aldehyde is then flowed to make contact with the soaked ion exchange resin to produce a product comprising DEG and/or TEG and less than 15 ppm aldehyde.

A polysulfone membrane is modified so that monomers are wafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

A polysulfone membrane is modified so that monomers are wafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

Present invention relates to a process to reduce butane sultone hydrolysis products (4-hydroxybutane-1-sulfonic acid, and bis(4-sulfobutyl) ether disodium) in sulfobutylether cyclodextrin reaction mixtures achieved with the combined use of a strong anion exchange resin having dialkyl 2-hydroxyethyl ammonium hydroxide functionality and a cation exchange resin.

Present invention relates to a process to reduce butane sultone hydrolysis products (4-hydroxybutane-1-sulfonic acid, and bis(4-sulfobutyl) ether disodium) in sulfobutylether cyclodextrin reaction mixtures achieved with the combined use of a strong anion exchange resin having dialkyl 2-hydroxyethyl ammonium hydroxide functionality and a cation exchange resin.

In various aspects, the present disclosure pertains to methods of performing a sample enrichment procedure, which comprise: adding a sample fluid that comprises at least one phospholipid and at least one target analyte to a sorbent that comprises a hydrophobic component and a cation exchange component, thereby resulting in sorbent with bound phospholipid and bound target analyte; adding an aqueous solution comprising an acidic compound and a salt; adding an organic solution to the sorbent thereby desorbing at least a portion of the bound phospholipid from the sorbent; and adding an elution solution to the sorbent, thereby desorbing at least a portion of the bound target analyte from the sorbent and forming a solution of the target analyte in the elution solution. In other aspects, the present disclosure pertains to kits, which may be used in conjunction with such methods.