University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Takashi Masadome

Abbrev:
Masadome, T.
Other Names:
Address:
Department of Chemical Science and Engineering, Ariake National College of Technology, Omuta, Fukuoka 836-8585, Japan
Phone:
NA
Fax:
+81-944-53-1361

Citations 7

"Determination Of Cationic Polyelectrolytes Using A Photometric Titration With Crystal Violet As A Color Indicator"
Talanta 2003 Volume 59, Issue 4 Pages 659-666
Takashi Masadome

Abstract: The reaction of the cationic dye, crystal violet (CV) with the anionic polyelectrolytes such as potassium poly (vinyl sulfate) (PVSK) results in a decrease of the absorbance of CV at the maximum absorption wavelength (590 nm). This change of the absorption spectra of the CV has been already applied to the determination of anionic polyelectrolytes using flow injection analysis method. In this paper, CV was applied to the indicator for the determination of cationic polyelectrolytes such as poly (diallyldimethylammonium chloride) (Cat-floc) by photometric titration, using a PVSK solution as a titrant. The end-point of the titration is detected as the break point of the titration curve. A linear relationship between the concentration of cationic polyelectrolyte and the end-point volume of the titrant exists in the concentration range from 0 to 5 x 10^-5 eq. mol L-1 for Cat-floc, glycol chitosan and methylglycol chitosan. The effects of the concentration of CV and coexisting electrolytes in the sample solution and the effect of pH of the sample solution on the degree of the change of absorbance at the end-point were also examined.

"Flow Injection Determination Of Iodide Ion In A Photographic Developing Solution Using Iodide Ion-selective Electrode Detector"
Talanta 2000 Volume 52, Issue 6 Pages 1123-1130
Takashi Masadome, Risa Sonoda and Yasukazu Asano

Abstract: A potentiometric flow injection determination method for iodide ion in a photographic developing solution was proposed by utilizing a flow-through type iodide ion-selective electrode detector. The sensing membrane of the electrode was Ag2S-AgI membrane. The response of the electrode detector as a peak-shape signal was obtained for injected iodide ion in a photographic developing solution. A linear relationship in the subnernstian zone was found to exist between peak height and the concentration of the iodide ion in a photographic developing solution in a concentration range from 0 to 6.0 x 10^-5 mol 1-1. The relative standard deviation for ten injections of 2 x 10^-5 mol L-1 iodide ion in a photographic developing solution was 0.96% and the sampling rate was approximately 12-13 samples h-1. The iodide ion could be determined under coexisting of an organic reducing reagent and inorganic electrolytes of high concentration in a photographic developing solution sample solution by the present method.

"Flow Injection Determination Of Bromide Ion In A Developer Using Bromide Ion-selective Electrode Detector"
Talanta 1999 Volume 50, Issue 3 Pages 595-600
Takashi Masadome, Yasukazu Asano and Takashi Nakamura

Abstract: A potentiometric flow injection determination method for bromide ion in a developer was proposed, by utilizing a flow-through type bromide ion-selective electrode detector. The sensing membrane of the electrode was Ag2S-AgBr membrane. The response of the electrode detector as a peak-shape signal was obtained for injected bromide ion in a developer. A linear relationship was found to exist between peak height and the concentration of the bromide ion in a developer in a concentration range from 1.0 x 10^-3 to 1.0 x 10^-2 mol L-1. The relative standard deviation for 10 injections of a 6 x 10^-3 mol L-1 bromide ion in a developer was 1.3% and the sampling rate was ca 17-20 samples h-1. The present method was free fr om the interference of an organic reducing reagent, an organic substance in a developer sample solution for the determination of bromide ion in a developer.

"End-point Detection Of The Potentiometric Titration Of Anionic Polyelectrolytes Using An Anionic Surfactant-selective Plasticized Poly (vinyl Chloride) Membrane Electrode And An Anionic Surfactant As A Marker Ion"
Fresenius J. Anal. Chem. 1999 Volume 363, Issue 3 Pages 241-245
T. Masadome, Toshihiko Imato, Yasukazu Asano

Abstract: A plasticized poly (vinyl chloride) (PVC) membrane electrode sensitive to dodecylbenzenesulfonate (DBS) ion is applied to the determination of anionic polyelectrolytes such as potassium poly (vinyl sulfate) (PVSK) by potentiometric titration, using a poly (diallyldimethylammonium chloride) (Cat-floc) solution as a titrant. The end-point of the titration is detected as the potential jump of the plasticized PVC membrane electrode caused by decrease in the concentration of DBS ion added to the sample solution as a marker ion, due to the ion association reaction between the DBS ion and Cat-floc. The effects of the concentration of DBS ion, coexisting surfactants and electrolytes in the sample solution and pH of the sample on the degree of the potential jump at the end-point were examined. A linear relationship between the concentration of anionic polyelectrolyte and the end-point volume of the titrant exists in the concentration range from 2 x 10^-5 to 4 x 10^-4 N for PVSK, alginate, and carrageenan.

"Flow Injection Determination Of Cationic Polyelectrolytes Using A Tetraphenylborate-selective Electrode Detector"
Bunseki Kagaku 1999 Volume 48, Issue 5 Pages 515-518
Takashi Masadome and Yasukazu Asano

Abstract: A potentiometric flow injection determination method for cationic polyelectrolytes utilizing a flow-through-type tetraphenylborate-selective electrode detector is described. The method is based on detecting any concentration decrease of the tetraphenylborate ion by the formation of an ion associate between cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (Cat-floc) and tetraphenylborate ion. The response of the electrode detector, as a peak-shaped signal, was obtained for injected cationic polyelectrolyte samples. A linear relationship was found to exist between the peak height and the logarithmic concentration of Cat-flee with a slope of 17 mV/decade over a concentration range of 5 x 10^-5 to 1 x 10^-3 mol L-1. The detection limit for Cat-flee was 1 x 10^-5 mol L-1. The sampling rate was ~12 samples/h.

"Flow Injection Spectrophotometric Determination Of Anionic Polyelectrolytes Using The Cationic Dyes"
Anal. Lett. 2001 Volume 34, Issue 15 Pages 2711-2719
Takashi Masadome

Abstract: The reaction of the cationic dye, crystal violet (CV) with the anionic polyelectrolytes such as potassium poly (vinyl sulfate) (PVSK) results in a decrease of the absorbance of CV at the maximum absorption wavelength (590 nm). This change of the absorption spectra of the CV was applied to the determination of anionic polyelectrolytes using flow injection analysis (FIA) method. Anionic polyelectrolytes such as PVSK and carageenan could be determined in the concentration range from 5 x 10^-7 to 2 x 10^-5 mol/l by the proposed method. The detection limit was ~I x 10^-7 M for PVSK. The sampling rate was ~25 samples h-1. The coexistence of foreign ions (Na+, Cl-, Br-, K+, SO42-, NO3-) at 200 times excess to an anionic polyelectrolyte did not interfere with the determination of the anionic polyelectrolyte.

"Flow Injection Fluorometric Determination Of Cationic Surfactants Using 3,6-bis(dimethylamino)-10-dodecylacridinium Bromide"
Anal. Lett. 1998 Volume 31, Issue 6 Pages 1071-1079
Takashi Masadome

Abstract: The anionic surfactant Na dodecylbenzenesulfonate (DBS) reacts with 3,6-bis(dimethylamino)-10-dodecylacridinium bromide (AO-10-D) to quench the fluorescence of AO-10-D. When a cationic surfactant is added to the mixed solution of AO-10-D and DBS, the fluorescence intensity increases with increasing concentration. of cationic surfactant because added cationic surfactant preferentially forms an ion associate with the DBS. The detection of increase in the fluorescence intensity was applied to the flow injection determination of a cationic surfactant. Cationic surfactants such as Zephiramine could be determined in the concentration. range from 1 x 10^-6 to 4 x 10^-5 mol/L by the proposed method. The sampling rate was ~10 samples h-1. The presence of Triton X 100, tetramethylammonium chloride, or tetraethylammonium chloride at concentrations. of 5, 25, or 25 times, respectively, in excess of that of the cationic surfactant did not interfere with the determination of the cationic surfactant.
Surfactants, cationic Zephiramine Fluorescence Indirect Interferences