Abstract: An estrogen derivatization method uses a quaternary cation-containing 5-fluoro-2,4-dinitrophenyl compound represented by Formula (1): where in Formula (1), X is a quaternary cation. A mass spectrometry method includes derivatizing estrogen by the above estrogen derivatization method. A derivatization reagent derivatizing estrogen includes a quaternary cation-containing 5-fluoro-2,4-dinitrophenyl compound represented by Formula (1), where in Formula (1), X is a quaternary cation.

Abstract: An object of the present invention is to provide a composite semipermeable membrane which has a high permeation rate and high salt removal performance and is excellent in terms of performance stability during long-term operation. The composite semipermeable membrane of the present invention includes: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, the separation functional layer includes a crosslinked polyamide and a hydrophilic polymer having an acidic group, and in the separation functional layer, a ratio of (molar equivalent of amino groups)/(molar equivalent of amide groups) is 0.18 or less.

Abstract: An object of the present invention is to provide a composite semipermeable membrane which has a high permeation rate and high salt removal performance and is excellent in terms of performance stability during long-term operation. The composite semipermeable membrane of the present invention includes: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, the separation functional layer includes a crosslinked polyamide and a hydrophilic polymer having an acidic group, and in the separation functional layer, a ratio of (molar equivalent of amino groups)/(molar equivalent of amide groups) is 0.18 or less.

Abstract: A separation membrane support includes a nonwoven fabric and has excellent membrane formability that achieves a high and stable yield when the separation membrane support supports various separation membranes, having excellent processability when a fluid separation element is produced, and having excellent mechanical strength. The nonwoven fabric has a boiling water shrinkage of ?0.2 to 2.0% in the length direction (longitudinal direction) after treatment in boiling water for 5 minutes.

Abstract: Provided is a composite semipermeable membrane having a polyamide separation-functional layer on a porous support layer, wherein the polyamide separation-functional layer has a yellow index of 10 to 40, and the actual length of the polyamide separation-functional layer per 1 ?m-length of the porous support layer is from 2 ?m to 5 ?m, or a composite semipermeable membrane having on a porous support layer a polyamide separation-functional layer prepared by polycondensation of polyfunctional amines with polyfunctional acid halides, wherein the polyamide separation-functional layer is formed by the steps of (A) interfacial polycondensation in which polyfunctional amines and polyfunctional acid halides are brought into contact at 40° C. to 70° C. and subsequent (B) heat treatment at 70° C. to 150° C. The composite semipermeable membrane according to the present invention has high boron removal performance and high water permeation performance.