title: Monolithic octadecylsilyl-silica gel column for the high-speed ion chromatographic determination of acidity.
abstract: A monolithic ODS-silica gel column modified by saturating it with lithium dodecylsulfate (Li-DS) was used to demonstrate the high-speed separation of H+ from other mono- and divalent cations, such as Na+, NH4+, K+, Mg2+ and Ca2+ using ion chromatography (IC). Using a 5 mM EDTA-2K solution containing 0.10 mM Li-DS (pH 4.80) as eluent, H+ was eluted with a sharp and symmetrical peak within 1.0 min before other cations at a flow-rate of 1.5 ml min(-1). The rapid elution of H+ and its conductimetric detection could be attributed to the presence of EDTA (HY2-), which can convert H+ ions as anions. i.e. H(+) + H2Y(2-) --> H3Y(-). The acidity of rainwater and deionized water samples was determined using this IC system with satisfactory results.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, 110, Nishiibara-cho, Seto, Aichi 489-0884, Japan. qun-xu@aist.go.jp
authors.forename: Qun
authors.initials: Q
authors.lastname: Xu
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tanaka
authors.forename: Masanobu
authors.initials: M
authors.lastname: Mori
authors.forename: Murad I H
authors.initials: MI
authors.lastname: Helaleh
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Hu
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hasebe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Toada
mesh_terms: D002118:Calcium / Q000302:isolation & purification; D002412:Cations; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D004492:Edetic Acid; D006859:Hydrogen / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008274:Magnesium / Q000302:isolation & purification; D011786:Quality Control; D015203:Reproducibility of Results; D012822:Silicon Dioxide; D012964:Sodium / Q000302:isolation & purification; D012967:Sodium Dodecyl Sulfate; D012996:Solutions
chemical_list: D002412:Cations; D007202:Indicators and Reagents; D012996:Solutions; C026679:octadecylsilica; D012967:Sodium Dodecyl Sulfate; D012822:Silicon Dioxide; D006859:Hydrogen; D004492:Edetic Acid; D012964:Sodium; C028913:dodecyl sulfate; D008274:Magnesium; D002118:Calcium