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Volume 29, Issue 9
Displaying 1-20 of 20 articles from this issue
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Liquid crystals as the stationary phase in gas chromatography. IIIKatsunori WATABE, Shigetaka SUZUKI, Shun ARAKI1980 Volume 29 Issue 9 Pages 575-579
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn the series of our investigation on a liquid crystal as the stationary phase in gas chromatography, it was found that the compounds with high dielectric constant are adsorbed in the column when a DC electric field is applied to it and at that time the liquid crystal should be or should have been changed to a nematic mesophase by the electric field. In this report, an application of this phenomenon is described for determination of the lower-dielectric compounds coexisting with large amounts of the higher-dielectric ones: by making the higher-dielectric compounds adsorbed in the column under the electric field, the lower-dielectric ones were separated and determined without any interference from the higher-dielectric ones. Some aromatic hydrocarbons present in a food oil were determined. The calibration curves were linear for the hydrocarbons under the electric field, and the interference from polar and volatile compounds in the food oil could be avoided. Furthermore, styrene, ethylbenzene, α-methylstyrene and propylbenzene in the extract from the fried noodle packed in a polystyrene container were determined.View full abstractDownload PDF (636K) -
Manabu IGAWA, Ikuo ITO, Masao TANAKA1980 Volume 29 Issue 9 Pages 580-584
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAdsorption characteristics of a crown ether polymer was studied and the polymer was tested as a packing material for ion chromatography of alkaline metal ions. The adsorption quantity was measured by a batch test. The eluent was pumped onto the polymer packed in a glass column (3 mm i.d.×250 mm) and the ions separated were detected by a conductance monitor. The adsorption capacity of the polymer was 1.92 meq/g and the ratio of an ion to a crown ring was 1 to 1 in a high ion concentration. The adsorption quantity increased with ion concentration and decreased with temperature. It was also effected by additives. In ion chromatography, lithium, sodium, and potassium were separated by the polymer when water was used as the eluent, and these ions gave shorter retention times at a higher temperature. The retention time changed when acid or alkali was added to the eluent. When methanol was added to the eluent, the retention time of these ions became longer. A cation showed different retention times depending upon the nature of anions in the solution. Thus, the mixture of sodium fluoride and potassium chloride gave four peaks of sodium fluoride, sodium chloride, potassium fluoride and potassium chloride. Therefore, it was able to analyze cations and anions at the same time.View full abstractDownload PDF (796K) -
Tatsuo AKIYAMA, Takuo SUGANO, Eiji NIKI1980 Volume 29 Issue 9 Pages 584-588
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSHydrogen-sensitive field effect transistors were fabricated and its performance was characterized as electrochemical sensors. This sensor has two advantages; (1) the size is very small, and (2) the sensor does not need any electrolytic current, so that the ion selective membrane is a completely insulated membrane. The devices were made on n-type silicon wafers of 2 inches in diameter and of 160 μm in thickness with (100) surface. The chip size is approximately 500μm×6000 μm. The FET has a 20 μm length, 3600 μm wide p channel. The gate insulator was thermally grown SiO2 film with approximately 1100Å thickness. Ta2O5 used as a hydrogen ion sensitive membrane was prepared by sputtering on the gate silicon oxide. For hydrogen ion sensitivity measurements, the source follower configuration was used. The liquid temperature was 24.6°C and the measurement was carried out in a dark room. The slope of pH-VGS-eq curve was about 56 mV/pH. The response time to abrupt pH change was less than few seconds and the response was reproducible.View full abstractDownload PDF (724K) -
Motohisa FURUSAWA, Masaki TACHIBANA, Takahiko TSUCHIYA1980 Volume 29 Issue 9 Pages 588-592
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe fluorescence emission intensity of naphthacene decreases rapidly in an ordinary bright room as a result of dimerization and oxidation. In the presence of anthracene, the intensity also decreases owing to the formation of the crossed dimer between naphthacene and anthracene. The authors found that the decrease was accelerated by the presence of the quinones such as naphthacenequinone and anthraquinone but could be prevented by addition of 3, 5-di-t-butyl- 4-hydroxytoluene (BHT) and treatment of the sample in the dark. A sample containing less than about 250 ng of naphthacene was dissolved in 5 ml of tetrahydrofuran (THF) containing 0.1 % of BHT in the dark at room temperature. Naphthacene could be determined by measuring the relative fluorescence intensity at 509 nm with excitation at 471 nm. A fluorescein sodium salt solution (10 ng/ml) and a 0.1 % of BHT-THF solution were used as a standard and a blank, respectively. A linear relationship was obtained over the concentration range from 2 ng to 50 ng naphthacene per ml. For the determination of trace amounts of naphthacene in anthracene, it was necessary to use the calibration curve prepared by using the standard naphthacene solution containing the same amounts of anthracene in the sample solution. The determination limit of naphthacene in anthracene was 0.1 ppm.View full abstractDownload PDF (724K) -
Toshiaki MIURA, Hidetoshi TAKAGI, Go KONISHI, Michiya KIMURA1980 Volume 29 Issue 9 Pages 593-597
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA simple fluorometric method for the determination of the steroidal estrogens was developed on the basis of the mechanism of the Kober reaction. On heating with 80 % sulfuric acid at 100°C for 5 min, the steroidal estrogen such as estriol was converted into C-2-sulfonated estratetraenyl cation having absorption and fluorescence maxima at 450 nm and 476 nm, respectively. It was found that p-hydroquinone stabilized the cation and as the result, the apparent molar absorptivity at 450 nm showed an increase of intensity by 2.5 times. This fluorescence reaction (2 % p- hydroquinone-80% sulfuric acid, 100 °C, 5 min, excitation wavelength: 440 nm, emission wavelength: 476 nm) was shown to be specific to the steroidal estrogens such as estriol, estrone and estradiol. The linear calibration curve obtained over the concentraion range (0.73.5) nmol estriol in 5 ml of the reaction mixture. The coefficient of variation of this method was 5.4 % (n=14) for 2.1 nmol of estriol. The proposed method can be applicable to the determination of the total estrogens in pregnancy urine.View full abstractDownload PDF (709K) -
Tokuichi KIM, Yohichi SUZUKI, Ichiroh ANAZAWA1980 Volume 29 Issue 9 Pages 597-601
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA gravimetric method for the analysis of phenols on the basis of formation of addition compounds between phenols and chromic anhydride was investigated. The addition compounds were easily formed in acetone solutions, but the stoichiometry in the compounds obviously differs from each other, depending on the kind of phenols employed. The differences become more obvious among naphthol isomers. In the preceeding paper, the authors reported a method for the analysis of naphthol isomers based on the above findings. In the present paper, it is reported that the pronounced differentiation of phenols can be achieved by the same method when a small amount of water is added. The stoichiometric amounts of chromic anhydride needed for the addition compounds was investigated on various phenols in the presence of water. As the result, it was found that the optimum conditions for the analysis of cresol isomers were as follows: water content (1.10 mol), aceton content (6.86 mol), reaction time (4 h), reaction temperature (50°C), quantity of reagent chromic anhydride (0.035 mol). In these conditions, the calibration curve obtained from a series of mixtures of m- and p-cresol was straight enough to provide good results within 2.0 % relative errors. This method is considered to be more useful for the chemical analysis of phenols than the bromination titration method or the nitration method.View full abstractDownload PDF (733K) -
Hiroko TAKEHARA, Yutaka HIRATSUKA, Masaaki HARAZONO1980 Volume 29 Issue 9 Pages 601-606
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe interferences of surfactants and anions on a nitrate ion-selective electrode potential were investigated. The selectivity coefficient of an anionic surfactant for the nitrate electrode was estimated to be above 103. The anionic surfactants caused noise and drift in the direction of the negative potential, making it impossible to determine nitrate at low concentrations. The interferences of the anionic surfactants could be effectively eliminated by being absorbed on the high porous polymer beads packed column or precipitated with higher amines from the solution of pH 3. But in the case of using the column method nitrate was lost due to the formation of an absorbable ion pair of nitrate with cationic surfactants above 10 mg/l. Phenol and benzoic acid at high concentrations influenced the electrode potential, but the interferences of those were eliminated by the same method. The interference of chloride ion was overcome by adding silver sulfate. However, in the presence of excess silver ion, the interference of nitrite increased probably due to the formation of [Ag(NO2)2]-. The nitrite should be decomposed completely with sulfamic acid. The analytical results of nitrate in industrial waste waters and airborne dusts by the present method were in good agreement with those obtained by the colorimetric xylenol method. The lower detection limit of nitrate was 2 mg/l and the coefficients of variation were 7% for 4.6 mg/l nitrate and 4 % for 53 mg/l nitrate, respectively.View full abstractDownload PDF (908K) -
Tsuyoshi NOMURA, Genkichi NAKAGAWA1980 Volume 29 Issue 9 Pages 607-611
Published: September 05, 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESS1-Amino-2-naphthol-4-sulfonic acid (ANS) is oxidized by dichromate ion very rapidly, whereas it is oxidized slowly with dissolved oxygen in a pH range from 1.5 to 4.5. ANS is polarographically inactive, but its oxidation product gives a sensitive tensammetric wave at the potential about -0.05 V vs. S. C. E. (pH 4.0). The Langmuir isotherm relation between the tensammetric wave height and the corresponding concentration of the oxidation product of ANS was observed; a linear calibration curve passing through an origin was obtained for (0.010.25)μg/ml of chromium (VI) ion concentration. The recommended procedure is as follows: to a sample containing from 0.2 μg to 6 μg of chromium(VI) ion in 25 ml measuring flask, 2.5 ml of 0.25 M potassium biphthalate-perchloric acid buffer was added. This is followed by successive additions of 2.5 ml of 0.1 M Na2H2edta, 2.5 ml of 0.5 M potassium fluoride, and is adjusted the pH to (3.84.2). It is added 2.5 ml of 5×10-3 M ANS and diluted to 25 ml with warm (50°C) redistilled water. The measuring flask is placed in a water bath at (50±0.2)°C for 30 min. It is cooled to 30°C to quench the reaction, and recorded the a.c. polarogram between +0.1 and -0.3 V vs. S.C.E. Interferences of Fe (III) and V (V) at 0.1 mg/25 ml and Cu (II), Ti (IV), Mn (II) and Hg (II) at 0.5 mg/25 ml could be eliminated by the addition of 0.05 M KF and 0.01 M Na2H2edta. The method of cupferronate extraction in sulfuric acid solution was successfully applied to separate the large amounts of interfering elements such as Fe (III), V (V), Cu (II), Mo (VI) and W (VI) from Cr (VI).View full abstractDownload PDF (639K) -
Studies on the combination of micro high performance liquid chromatography and infrared absorption spectrometry. IKiyokatsu JINNO, Chuzo FUJIMOTO, Masayoshi IDEHIRA, Tsugio TAKEUCHI, D ...1980 Volume 29 Issue 9 Pages 612-617
Published: September 05, 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe microscale liquid chromatographic technique has been recently developed. The technique requires only small quantities of sample, carrier and packing material, and the associated instrumental components can be simplified more than those of conventional high performance liquid chromatographs on the market. Therefore, it is very easy to combine liquid chromatography with spectrometric techniques such as mass spectrometry or infrared absorption spectrometry. In this study, we investigated the combination of micro high performance liquid chromatography and infrared absorption spectrometry with use of KBr disk as buffer memory. Our results indicate that KBr disk-buffer memory are very useful to reproduce the detected chromatograms easily, when necessary. We also examined the applicability of Fourier transform infrared spectrometer for the present method, and could enhance the sensitivity of the present method. We have developed an automatic equipment for collecting eluate on the KBr buffer memory. This equipment would enable us to obtain the infrared chromatograms of pyrene lower than 10 micrograms as readily as ultraviolet chromatograms.View full abstractDownload PDF (721K) -
Akira NAKAZAWA1980 Volume 29 Issue 9 Pages 617-621
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAn infrared spectrophotometric method for determining the concentration ratio of any two components in multicomponent mixtures is described. Although the conventional infrared spectrophotometric analysis has been carried out by making use of only positions of main absorption peaks in spectra, in the method based on a partial regression coefficient ratio, the uses of not only the main peak position but also several other positions in the absorption band are suggested. That is, absorbance values, Am, of mixtures are measured in a certain spectral region at a given wavenumber interval, and assuming that Am is represented by the multiple regression model, we have that:
Am=A0β+e…(1)
where A0 is the absorbance data of each component, β is the partial regression coefficient, and e is the experimental error. When the Beer's law conforms in the spectral region with respect to the absorption of each component, the partial regression coefficient, βiof a component i in equation (1) can be given by:
βi=lCi/l0iC0i…(2)
where l and Ci are the pathlength of the cell used and the concentration of the component, i, in the mixture respectively. l0i and C0i are those for the pure standard of component i. Therefore, the concentration ratio (Ci/Cj) of any two components, i and j, in mixtures is proportional to the partial regression coefficient ratio of the two components, i.e., ratio of βi/βj. This linear correlation was used for the determination of the concentration ratio of zinc and copper in the coprecipitated mixtures of zinc and copper 8-hydroxyquinolates by applying a slight difference of the absorption band due to C-O stretching frequency in these two 8-hydroxyquinolates. Though the absorption bands were not well-separated between the complexes, a plot of the partial regression coefficient ratio (βCu/βZn) against the concentration ratio(CCu/CZn) gave mostly a straight line. When the complexes were subjected to the measurement of an infrared spectrum by using a liquid cell 1 mm thick with KBr windows against chloroform as the reference, the reproducibility of this method was (1.1?1.3)% as a coefficient of variation in the concentration ratio range of 0.1 to 0.9, and this method gave about 10-fold enhancement in the sensitivity compared with the conventional methods.View full abstractDownload PDF (706K) -
Hiroshi KOBATAKE, Osamu KITAGAWA, Takahiro SUEKANE, Yukitoshi MURAKAMI ...1980 Volume 29 Issue 9 Pages 622-627
Published: September 05, 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSSynthesized alditol acetates from free and partially methylated neutral monosaccharides were studied for their separation and identification in isothermal gas-liquid chromatography using several commercial adsorbents. Alditol acetates from almost all free and monomethylated neutral monosaccharides could be separated from one another, and they were determined by combination of the data with Tabsorb® (190 °C), 3% ECNSS-M/Gaschrom-Q (190°C) and 3% Silar-10 C/Chromosorb-W (190°C). Relative retention times of 13 kinds of free, 6 of deoxy-, 2 of anhydro- and 13 of monomethylated-alditol acetates were listed. Relative retention times of 8 polymethylated alditol acetates from arabinose, 18 from glucose, 21 from galactose and 14 from mannose with 3% ECNSS-M/ Gaschrom-Q (180°C), Tabsorb® (180°C) and 10 % SE-30/Chromosorb-W (180°C and 210°C) were also given. This method is particularly useful for the analysis of methylated sugars in establishing the structure of complicated polysaccharide by the permethylation techniquie.View full abstractDownload PDF (857K) -
Akira IINO, Atsushi MIZUIKE1980 Volume 29 Issue 9 Pages 627-631
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAmorphous materials prepared from alkoxides have been proposed as standard samples for the quantitative analysis of glasses by secondary ion mass spectrometry (SIMS). Ethanolic solutions containing silicon tetraethoxide, aluminum s-butoxide, sodium methoxide, calcium ethoxide, and boric acid were solidified by evaporation of the solvent and hydrolysis at (2025)°C and (4050) % of relative humidity. The resulting numerous flakes (3 mm×3 mm, 50 μm thick) were heated at 550°C to obtain the standard samples of compositions, 81 SiO2-13 B2O3-2 Al2O3-(1.33.9) Na2O-(0.23.5) CaO wt %. They had similar properties to corresponding glasses and homogeneity sufficient for quantitative analyses by SIMS. However, the standard samples produced more molecular ions (SiO+) than corresponding glasses. This suggested minor differences in structure between the two. Pyrex glass and Japanese standard reference material borosilicate glass R501 were analyzed by SIMS for sodium and calcium with satisfactory results by the use of calibration curves prepared from three standard samples. The suggested standard samples can be especially useful when standard glass samples are not commercially available or can not be prepared easily by conventional melting procedures or diffusion processes.View full abstractDownload PDF (713K) -
Masahiko TSUCHIYA, Tetsuji TAIRA, Yukio TOYOURA1980 Volume 29 Issue 9 Pages 632-637
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSWe have developed a new ionization detector for organic compounds as liquids or in solution at atmospheric pressure by utilizing Penning ionization. It was confirmed that water and acetonitrile whose ionization potentials are higher than the excitation energy of carrier gas argon (11.6 eV) can be used as solvents for this method. Dissolved compounds whose boiling points were lower than around 250°C gave their ions at room temperature, but it is necessary to heat the solution for observing ions from compounds with higher boiling points. The heating temperature depends on the solvent used and it is fairly low compared with the bp of the compound itself, e.g., it was about 60°C for the aqueous solution of dimethyl phthalate (bp: 284°C). When a sample size is kept constant, good linearity is observed in the relation between the ion current and total ion abundance of a solute and its concentration. The detection limit at present is the order of ng as an absolute amount and the order of ppm as its concentration. This detector may be used for liquid chromatography. Information about solution chemistry may also be provided.View full abstractDownload PDF (808K) -
Itsuo MORI, Yoshikazu FUJITA, Yoshiyuki KAMATA, Masako MAEYAMA, Takehi ...1980 Volume 29 Issue 9 Pages 638-640
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA simple and rapid method was developed for spectrophotometric determination of molybdenum(VI) and tungsten(VI) with Pyrogallol Red (PR) and cetylpyridinium chloride (CPC). The recommended procedure is as follows: Sample solution containing less than 30 μg of molybdenum(VI) {or <90 μg tungsten (VI)} was transfered to a 10-ml volumetric flask, and 2.0 ml of 1.0×10-2 M CPC and 1.5 ml of 1.0×10-3 M PR in methanol were added. The pH of the solution was adjusted to 4.7 with acetate buffer. The solution was diluted to the mark with water and kept at (2030)°C for 50 min, and then the absorbance was measured at 610 nm for molybdenum(VI) and 600 nm for tungsten(VI) against a reagent blank. Tungsten(VI) in the presence of molybdenum(VI) was determined by measuring the absorbance at 530 nm against reagent blank, and then molybdenum(VI) was determined by the calibration curves prepared in the presence of various amounts of tungsten(VI). The Sandell's sensitivities were 0.0028 μg/cm2 for molybdenum(VI) and 0.0096 μg/cm2 for tungsten(VI). The effect of foreign ions on the absorbance of the complex were examined. The mole ratio of Mo(VI), or W (VI) and PR in the complex was 1:2. Al(III), Fe(III) and Th(IV) was masked with EDTA, or sodium fluoride.View full abstractDownload PDF (400K) -
Evaluation of the effectiveness of internal standards and briquetting samplesYasuo IWATA, Kazuko MATSUMOTO, Keiichiro FUWA1980 Volume 29 Issue 9 Pages 640-644
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSChromium in rocks and sediments was determined by energy dispersive X-ray fluorescence spectrometry, with special interest focused on the effectiveness of internal standards and the comparison of powder sample with briquet one. Determinations were based upon standard addition method. Chromium solution (10000 μg/ml) were added to 2 g powder of JB-1 and Sanshiro-ike pond sediment at the level of (100500)μg/g, whereas Cr2O3 powder was added to River Sediment (NBS SRM 1645). Vanadium and manganese originally present in the samples were used as internal standards for JB-1 and pond sediment, and Ce was added as internal standard for River Sediment. It appears that the use of internal standard does not significantly improve the precision for the determination of Cr at ppm level. Measurement on 0.5 g powder itself as a sample results in good precision and accuracy; no special pretreatment such as briquetting is necessary.View full abstractDownload PDF (722K) -
Akihiro ONO, Naoharu YAMAGUCHI, Ryutaro MATSUMOTO1980 Volume 29 Issue 9 Pages 644-647
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAn ion-exchange method using a constant potential coulometric detector, was applied to the determination of micro amounts of heavy metal ions in industrial waste water. In order to improve the sensitivity and selectivity of the method, the analytical conditions were studied in details. The following analytical conditions are recommended; pH range of the sample solution: 2.05.0, sample volume: 2.0 ml, resin: Hitachi No. 2611 (degree of crosslinking: 10 %, size: 15 μm), column: 100 mm×90 mm i.d., 50°C, eluent: 0.2 M NH4-tartrate (pH 4.6), 90 ml/h, eluent for removal of Ca2+, Mg2+, etc.: 0.5 M Na-tartrate (pH 5.0), electrolyte: 0.01 M Hg-diethylene triamine pentaacetate-1 M NH4OH-0.1 M NH4NO3, detection potential: 0.24 V vs. Ag-AgI. Under the recommended conditions, the following heavy metal ions can be determined within 25 min: Cu2+ (down to 0.02 ppm), Zn2+ (0.02 ppm), Co2+ (0.02 ppm), Pb2+ (0.05 ppm) and Cd2+ (0.05 ppm).View full abstractDownload PDF (489K) -
Sachiko SAKURA1980 Volume 29 Issue 9 Pages 647-650
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn aprotic solutions of inorganic ions there are many polarographic data on the reduction wave often accompanied by the maximum wave, and this makes accurate measurements of half wave potentials impossible. For instance in tetrabutylammonium perchlorate (Bu4NClO4)-hexamethylphosphoric triamide (HMPA) solution, the zinc ion showed a large, diffusion controlled reduction wave, but accompanied by a large maximum (E1/2=-1.7 V). In the case of cobalt ion, the polarographic reduction was similar to the zinc ion. Tetraethylammonium ion (Et4N+), N, N-hexamethylenepiperidinium ion (5N6+), hexamethonium ion were found to be very good maximum suppressors for these cases, and the effect was more enhanced in the order of Et4N+<5N6+<hexamethonium ion. In the case of barium ion (E1/2=-2.4 V) in Li+-HMPA, effects of the three maximum suppressors were too strong and Ba2+ could not be reduced at a certain concentration of the suppressor. The drop time of mercury at -1.7 V and -2.4 V became shorter in the order of hexamethonium ion <5N6+, <Et4N+<Bu4N+<Li+, which suggests the order of adsorption of these ions on the mercury electrode.View full abstractDownload PDF (455K) -
Ken OGASAWARA, Masatoshi OHTA, Kenzo ABE1980 Volume 29 Issue 9 Pages T61-T64
Published: September 05, 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSMicrodetermination of potassium in sodium iodide was developed by the standard addition method. Twenty grams of sample were dissolved in 50 ml of water in a quartz beaker. To the solution, 30 ml of concentrated hydrochloric acid and 30 ml of 30 % hydrogen peroxide were added, and evaporated to dryness. By this process sodium iodide was converted into sodium chloride. The cake thus obtained was dissolved in water and diluted to exactly 200 ml. To 25 ml aliquots of the solution, the standard potassium and cesium chloride solutions were added and diluted to 50 ml with water; the concentration of potassium was 01 mg/l and that of cesium 4 mM. These solutions were introduced into an air-propane flame and the absorbances were measured at 769.9 nm. During the conversion reaction, hydrochloric acid was completely decomposed, and remained hydrogen peroxide had no influence for absorbance, and other backgrounds were negligible. The linear calibration curve was obtained in the range 02mg of potassium per liter. Potassium in sodium iodide was determined by this method within the coefficient of variation of ±(203) % in the range (1.732.5) ppm.View full abstractDownload PDF (518K) -
Masayoshi NISHIYAMA, Sanae KISHIDA1980 Volume 29 Issue 9 Pages T64-T67
Published: September 05, 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe chelatometric titration of iron(III) with ethylenediaminetetraacetic acid (EDTA) and Xylenol Orange (XO) was tested. The recommended procedure is as follows: The pH of a sample solution containing more than 1×10-4 mol of iron(III) was adjusted to 1.22.3 in the absence of acetic acid, or to 1.25.3 in the presence of acetic acid added at 1×104-fold molar ratio to iron(III) for preventing hydrolysis of iron(III). After addition of about 1 μmol of XO as the indicator, the solution was titrated with 0.01 M EDTA solution at (5090)°C. At the equivalence point the very sharp color change from reddish violet to yellow was observed at pH 1, 23, and from blueish violet to reddish brown at pH 35.3. No blocking phenomenone was observed.View full abstractDownload PDF (616K) -
Machiko TEZUKA1980 Volume 29 Issue 9 Pages T68-T72
Published: September 05, 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSEffects of two chloride ion masking agents on values of chemical oxygen demand with acidic potassium permanganate method at 100°C (CODMn) were compared. For the purpose, round robin tests were carried out by Technical Committee of Japan Iodine Export Association. The CODMn of two kinds of subsurface brine, namely, crude brine (as source material of iodine) and waste brine (after extraction of iodine) were determined by two methods, i.e., ordinary one {JIS K 0102(13)-1974, Ag2SO4 method} and revised one {JIS K 0101(17)-1979, AgNO3 method}, respectively. The pre-arranged samples were separately analyzed by six laboratories, and the results were compared. In all cases, the CODMn obtained by AgNO3 method were higher than those by Ag2SO4. Calculated COD5 (CODMn as titrant volume is 5 ml) from the results both by Ag2SO4 and AgNO3 method, were 45.1, 61.8 mgO/l for crude brine, 34.0, 42.7 mgO/l for waste brine, respectively. Average CODMn difference between the two methods which were carried out with same volume of the samples were 13.7 mgO/l for crude brine and 8.2 mgO/l for waste brine. Conclusively, a clear discrepancy is found in the chloride ion masking effects on CODMn values of subsurface brine between silver sulfate and silver nitrate.View full abstractDownload PDF (699K)
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