Entity

Time filter

Source Type

Nishi-Tokyo-shi, Japan

Kemmei T.,Toyama Institute of Health | Kodama S.,Toyama Institute of Health | Yamamoto A.,Chubu University | Inoue Y.,Nippon Filcon Co. | Hayakawa K.,Kanazawa University
Food Chemistry | Year: 2013

A convenient HPLC method for the quantitative determination of EDTA in foods was developed. EDTA in food samples was easily extracted with water by ultrasonication. After converting to Fe(III) complex in the presence of Fe(III) ions, EDTA was separated on a reversed-phase C30 column and detected with ultraviolet detection (260 nm). Citrate and malate, which are present in many foods, also formed Fe(III) complexes but they did not interfere the chromatographic detection of EDTA. The method allowed determination of EDTA in foods at concentrations as low as 0.01 mmol/kg. Good recoveries (95.2-101%) were obtained by the standard addition method on four samples with high repeatability (RSD, 0.8-3.4%). The method was successfully applied to the analysis of EDTA in carbonated drinks, jellies, canned beans, canned corn and food supplements. © 2012 Elsevier Ltd. All rights reserved.


Nakashima Y.,Metrohm Japan Ltd. | Nakashima Y.,Chubu University | Yamazaki M.,Metrohm Japan Ltd. | Suzuki S.,Metrohm Japan Ltd. | And 4 more authors.
Bunseki Kagaku | Year: 2013

The applicability of metal oxide as a selective extractant for ionic compounds was investigated to establish an easy and selective determination method using ion chromatography coupled with conductivity detection. The extraction properties of zirconia and titania for glyphosate (N-(phosphonomethyl)glycine, GLYP) as an analyte were evaluated. Although it has been recognized that both zirconia and titania have high affinity for phosphate compounds, the leakage of GLYP from a solid-phase extraction cartridge packed with the titania used in this study was observed. On the other hand, zirconia could perform an effective extraction of GLYP with high retention ability. Also, a solid-phase extraction cartridge packed with 35 mg of the zirconia was able to certainly entrap GLYP in spite of a sample load of 250 mL. GLYP entrapped on the zirconia could be eluted with 2 mL of 0.4 M sodium hydroxide as an eluent. GLYP in the effluent could be sensitively detected by ion chromatography with conductometric detection using neutralization employing a suppressor module. The proposed method was applied to the determination of GLYP in urban river water samples. The limit of quantification was around 0.001 mg L-1 for GLYP. © 2013 The Japan Society for Analytical Chemistry.


Kamichatani W.,Nippon Filcon Co. | Inoue Y.,Nippon Filcon Co. | Inoue Y.,Chubu University | Yamamoto A.,Chubu University
Analytica Chimica Acta | Year: 2015

A novel water-holding adsorbent bonded with a zwitterionic polymer, diallylamine-maleic acid copolymer, was developed. With this adsorbent, hydrophilic solutes are partitioned by a hydration layer that forms on the zwitterions, as a main separating force. When the adsorbent was used to separate saccharides by normal-phase partition chromatography, the saccharides eluted in the order, mono-, di- and trisaccharide. The elution profile for mono- and di-saccharides was similar but not identical to that on anion exchange columns. This indicated that the adsorbent exhibited a complex retention behavior by the existence of both anion and cation exchange moieties in the functional polymer. Selecting Na+ as a counter-ion of the maleate moiety enhanced the retention of saccharide. When used in an high performance liquid chromatography (HPLC) system with gradient elution, the adsorbent enabled the simultaneous analysis of mono-, di- and oligosaccharides. © 2014.


Kagaya S.,University of Toyama | Nakada S.,University of Toyama | Inoue Y.,Nippon Filcon Co. | Kamichatani W.,Nippon Filcon Co. | And 5 more authors.
Analytical Sciences | Year: 2010

Solid phase extraction using a mini cartridge packed with 22 mg of chelate resin immobilizing carboxymethylated pentaethylenehexamine was successfully utilized for separation/preconcentration of cadmium in water samples prior to liquid electrode plasma atomic emission spectrometric (LEP-AES) determination. The combined method with the extraction and LEP-AES was applicable to the determination of cadmium in the certified reference materials (EU-L-1 wastewater and ES-L-1 groundwater); the detection limit was 0.20 μg in 200 mL of sample solution (500-fold preconcentration). 2010 © The Japan Society for Analytical Chemistry.


Inoue Y.,Nippon Filcon Co. | Inoue Y.,Chubu University | Kamichatani W.,Nippon Filcon Co. | Yamamoto A.,Chubu University
Bunseki Kagaku | Year: 2014

Novel water-holding separation materials (Betaine-resin and DAM-resin) having zwitter-ionic functional groups were synthesized by introducing sulfobetaine and diallylamine-maleic acid copolymer to a hydrophilic methacrylate base resin. These separation materials showed high water-holding ability equal to ion-exchange resins. Their extraction efficiencies of watersoluble compounds in acetonitrile solutions were evaluated by the solid-phase extraction method using cartridges packed with the materials. The materials showed high affinity for nucleobases, nucleosides and organic acids, and could be extracted quantitatively. The DAMresin could quantitatively extract highly water-soluble solutes, such as glucose and glucosides. Therefore, the chromatographic properties for the water-soluble solutes on the DAM-resin were evaluated by HPLC. Because the logarithm of the retention factors (Log k) of the watersoluble solutes showed good correlation to their Log Po/w (logarithm of octanol-water partition coefficient), it was recognized that the water-soluble compounds should be able to be partitioned into the water-rich layer associated with the zwitterionic moieties. On the other hand, the ionic solutes were retained by a mixed interaction mode combined with an electrostatic interaction. However, their retentions could be regulated by controlling the composition of the copolymer, the characteristic of salt in the mobile phase, and the mobile phase pH. Furthermore, a fibrous adsorbent (DAM-fiber) was successfully developed by the wet-spinning of viscose rayon with the DAM, and was characterized for the extraction and adsorption of water-soluble compounds. Further, the DAM-fiber also showed high decline rates for volatile acidic and basic substances in atmosphere, and demonstrated a high ability as an adsorption/removal material for odor substances. © 2014 The Japan Society for Analytical Chemistry.

Discover hidden collaborations