title: Device to generate high purity hydroxide solution in-line for ion chromatography.
abstract: Herein, we report a new device that generates a high-purity hydroxide solution in line. The device's container has three compartments that are isolated from each other by two cation exchange (CE) membranes. In each end of the container, an electrode is installed. The three compartments are filled with ion exchange resins. A bipolar boundary is a composite boundary comprising anion- and cation-exchangers. This device has two bipolar boundaries, which are used to separate the location of hydroxide solution generation from the location where water is electrolyzed. Therefore, it can produce high-purity hydroxide solutions that are free from gases and anionic impurities. The hydroxide solution is generated on the basis of an electrokinetic phenomenon at the surfaces of ion-exchange resins and membranes in an electric field; NaOH concentration can be controlled at rates from 0.01 to 100mM per 1mL/min by adjusting the electrical current (0-200mA) applied to the device. As the generated solution is used as an eluent for a suppressed anion chromatography, the electrical conductivity of the effluent from the suppressor is as low as that of ultra-pure water. Thus, the noise of the base-line electrical conductivity is improved, and so the detection limit of anions on the sub-ng/mL order can be achieved.
authors.affiliation: Nichiri Mfg. Co., Ltd., 324-5, Takatu, Yachiyo, Chiba 276-0036, Japan. Electronic address: h.masunaga@nichiri-mfg.co.jp.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Masunaga
authors.affiliation: Nichiri Mfg. Co., Ltd., 324-5, Takatu, Yachiyo, Chiba 276-0036, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Higo
authors.affiliation: Nichiri Mfg. Co., Ltd., 324-5, Takatu, Yachiyo, Chiba 276-0036, Japan.
authors.forename: Mizuo
authors.initials: M
authors.lastname: Ishii
authors.affiliation: Nichiri Mfg. Co., Ltd., 324-5, Takatu, Yachiyo, Chiba 276-0036, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Maruyama
authors.affiliation: Department of Applied Science, Okayama University of Science, 1-1 Ridaicho, Okayama 700-0005, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamazaki
mesh_terms: D002852:Chromatography, Ion Exchange / Q000295:instrumentation*; D006878:Hydroxides / Q000737:chemistry*; D007475:Ion Exchange Resins / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D006878:Hydroxides; D007475:Ion Exchange Resins; D012996:Solutions; D014867:Water
keywords: Anion analysis; Electrokinetic phenomenon; Generation of hydroxide solution; Ion chromatography; Two bipolar boundaries