All issues
Volume 27, Issue 12
Displaying 1-16 of 16 articles from this issue
- |<
- <
- 1
- >
- >|
-
Yoshikatsu MIYASHITA, Kazuo OIKAWA, Mariko HIKICHI, Hidetsugu ABE, Shi ...1978 Volume 27 Issue 12 Pages 741-743
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe techniques of automated infrared spectrophotometry have been so far developed with computer-dispersion spectrophotometer coupling systems. Usually the data processing was implemented after completion of digitization of raw infrared spectra. On the other hand, real-time data processing of raw data during the data sampling brings about considerable saving of time and effective use of computer storage. This paper describes an on-line quantitative infrared determination system. Because of high wavenumber reproducibility of the spectrophotometer this on-line system proved to be suitable for programmed wavenumber scanning control. The computer controlled spectrophotometer is automatically set at a starting wavenumber. To calculate the smoothed transmit- tance in real time a least square polynomial of degree two is used. After the measurement of a sample, solvent compensated transmittance data for quantitative determination are obtained. Three isomeric xylenes could be precisely determined by this on-line system.View full abstractDownload PDF (566K) -
Junichi SAKAI, Hiroaki MIZUTA1978 Volume 27 Issue 12 Pages 744-748
Published: December 05, 1978
Released on J-STAGE: May 07, 2010
JOURNAL FREE ACCESSA rapid and selective method for determination of cysteine alkyl esters (cysteine methyl ester and cysteine ethyl ester) by high performance liquid chromatography equipped with a UV monitor was established. This method was based on analysis by high performance liquid chromatography using a micro particulate, bonded reversed-phase column after conversion to their benzoyl derivatives. The procedure was as follows: 10 mg of cysteine alkyl ester, 0.1 ml of triethyl-amine and 1.5 × 10-4 mol of benzoyl chloride were dissolved in 10 ml of chloroform and the mixture was allowed to stand for 10 min at room temperature. After evaporated to dryness, the residue was dissolved in 2 ml of the internal standard solution. One μl of this solution was injected into the chromatograph. The column (4 mm I.D. × 30 cm) packed with μBonda-pack C18 was equilibrated and eluted with acetonitrile/ 0.05% ammonium bicarbonate buffer solution (pH 6.5) (55/45), and the column effluent was monitored at 254 nm. This method was not disturbed by cysteine, cystine dialkyl esters, cystine and cysteic acid which are expected as impurities or decomposition products of cysteine alkyl esters. When applied to the determi-nation of tablets, this method had enough accuracy and higher selectivity compared with colorimetric method using 2, 2'-dithiodipyridine.View full abstractDownload PDF (685K) -
Toyoshi NAGAI, Toshio MATSUDA, Yoshinaga KOUJI1978 Volume 27 Issue 12 Pages 749-753
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe redox reaction of lead dioxide suspension with chromium(III) salt in alkaline solutions was investigated by polarographic method. Both of the reaction products, Pb(II) and Cr(VI), gave reduction waves in alkaline solutions at the dropping mercury electrode, but they were not separated well each other. But, when EDTA was added to the sample, as the wave of Pb(II) shifted to more negative potential region than that of Cr(VI), both waves were separated well. The polarographic behavior of the first wave was identical with that of chromate ion. Its diffusion current was found to be proportional to the concentration of Cr(VI). The proposed procedure for the determination of the molar ratio of Cr(III) to Pb(IV) in this redox reaction is as follows: Into a 200 ml Erlenmeyer flask containing 10 ml of 1 M KNO3, diluted by (6075) ml of distilled water, 2.00 ml of 0.05 M lead tetraacetate solution was added dropwise and hydrolyzed. After the pH value of this suspension was adjusted to about 12.5, 3 ml of 0.05 M EDTA solution and (2.0016.00) ml of the 0.006 M chromium(III) salt solution were added. After the mixture was diluted to 100 ml and stirred for 10 min, remaining PbO2 was separated off by centrifuge. The polarogram was measured using the supernatant solution after the removal of oxygen in it. The diffusion current of the reduction wave of Cr(VI) was measured at -1.20 V vs. SCE. The molar ratio was determined from the relation between the diffusion current of Cr(VI) and the volume of Cr(III) solution added. From the results of this method, the equivalence point is determined as 2:3 in molar ratio of Cr(III) to Pb(IV), within ±2.0% error for the calculation. The pH effect on its reaction rate was also examined.View full abstractDownload PDF (1012K) -
Masayoshi TATSUZAWA, Takuji YAMAMIYA, Akira EJIMA, Nobuharu TAKAI1978 Volume 27 Issue 12 Pages 753-758
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe rapid, sensitive and specific high-speed liquid chromatographic method for the quantitative analysis of antitussive, expectorant and antihistaminic in anticold preparations was established. Noscapine was separated by injection of methanol solution to a column (50 cm × 3 φ ID) packed with polymethylmethacriratestyrene-divinylbenzene copolymer (1:1, MCL-DVB). Dextromethorphane HBr was separated by injection of methanol solution to a column (50 cm × 3 φ ID) packed with MCL-DVB(1 : 2). Alimemazine tartrate, prome-thazine methylenedisalicylate and isothipendyl HCl were prepared by injection of methanol solution to a column (50 cm × 3φ ID) packed with hydroxymethylated MCL-DVB. Noscapine, dextromethorphane, alimemazine, promethazine and isothipendyl were eluted with mixture of methanol and 28% ammonia-water (99:1) and detected at 220 nm, 227 nm and 254 nm. Other ingredient such as acetaminophen, phenacetin, ethoxybenzamide, caffeine and methylephedrine HCl, did not interfere with the analysis. The method is sensitive and accurate for analysis of antitussive, expectorant and antihistaminic in anti-cold preparations.View full abstractDownload PDF (1022K) -
Determination of trace amount of lead by atomic absorption spectrometry after hydride-evolution process. IKazuo JIN, Mitsuhiko TAGA, Hitoshi YOSHIDA, Seiichiro HIKIME1978 Volume 27 Issue 12 Pages 759-764
Published: December 05, 1978
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA method was proposed for the rapid and sensitive determination of lead by atomic absorption spectrometry after hydride evolution process. Compared with the cases using borohydride solution alone as a reductant, the sensitivity was enhanced extremely by the addition of dichromate, hydrogen peroxide or persulfate to the acidic solution of lead(II) prior to the injection of borohydride solution. Permanganate also exhibits such enhancement effect in some grade. When dichromate is used together with borohydride, malic acid or tartaric acid should be used as the acid. Various factors affecting the evolution of lead hydride, especially acids (and its acidity) and the concentration of above sensitivity enhancement reagents, were investigated. The determination procedure is as follows: Five to ten cm3 of sample solution was put into a reaction vessel (Hitachi Co., Ltd.), reagents were added, and the solution having one of the following compositions was prepared; (A) 0.25 M malic acid (tartaric acid)-0.025 M dichromate, (B) 0.5 M HNO3 (HCl, HClO4, 0.25 M H2SO4)-1.3 M H2O2, (C) 0.3 M HNO3 (HCl, HClO4)-0.12 M K2S2O8. The volume of the solution was adjusted to 20 cm3. After the injection of 5 cm3 of w/v NaBH4, the evolved lead hydride was introduced into nitrogen-hydrogen flame of the atomic absorption spectrometer. The detection limit of the method (S/N=2) is 15, 20, and 20 ng for (A), (B), and (C) system, respectively. The calibration graph was linear up to 1.5μg Pb. Effect of diverse ions on the determination of lead was also examined.View full abstractDownload PDF (979K) -
Fumie ISHINO, Fumiaki GOSHIMA1978 Volume 27 Issue 12 Pages 764-767
Published: December 05, 1978
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSCysteine reacts on a silica gel thin layer with ninhydrin dissolved in sulfuric acid or phosphoric acid and forms a reddish-purple spot, while many other amino acids do not color. This specific color reaction was applied to the spectrophotometric determination of cysteine in amino acids mixture. The procedure is as follows : color reagent was prepared by dissolving 100 mg of ninhydrin in 10 ml of 6 M phosphoric acid. As a sample solution 1 mg each of standard amino acid was dissolved in 4 ml of 0.5 M hydrochloric acid. Twenty microliter of the sample solution was spotted on silica gel thin layer. After spraying the ninhydrin solution, the plate was heated at about 80°C for (2025) min. A reddish-purple spot appeared. The colored spot was scraped and eluated from the silica gel layer by means of 5 ml of 1-pentanol. The absorbance of the eluate in 1-pentanol could be measured at 565 nm. The molar absorption coef-ficient was 3.6 × 104 cm-1 mol-1 1. But this method was interfered in the presence of 50μg of proline and 100μg of tryptophan or hydroxyproline in 20 μl of the sample solution. By this method, 3 to 20 μg of cysteine can be determined with an error of 5 per cent.View full abstractDownload PDF (621K) -
Study of stationary phaseKunishige HIGASHI, Kazuyoshi HAGIWARA1978 Volume 27 Issue 12 Pages 768-772
Published: December 05, 1978
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSEffect of pore size of polystylene gel on the profile of chromatogram was studied. Three kinds of the gels, HSG-10, HSG-15, and HSG-40 (Shimadzu), were used as stationary phases independently, or as the combined form. The sample solution was obtained by dissolving the crude oils in tetrahydrofuran, and 12μl of the solution was injected into the column held at 50°C. Tetrahydrofuran was used as an eluent at the flow rate of 1.34 ml/min. The chromatogram was recorded by measuring the absorbance of the eluate at 254 nm. Chromatographic profiles of four crude oils, Murban, Iranian light, Oman and Minas, were compared with each other. The profile of the chromatograms of the same oil as well as the discrepancy of the profiles among oils changed considerably with the pore size of the gel used. χ20 value was calculated to evaluate the difference of the discrimination capability of columns. A 4 × 8 contingency table was obtained with the data of eight peak intensities of each chromatogram of four crude oils, and χ20 value on each column was calculated. It was found that χ20 value of HSG-15 was largest, and its discrimination capability of its column was the highest. The discrepancy of the profiles between two oils was also evaluated by χ20 values.View full abstractDownload PDF (747K) -
Study of weathering of oilKunishige HIGASHI, Kazuyoshi HAGIWARA1978 Volume 27 Issue 12 Pages 772-776
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA profile change of gel permeation chromatogram with weathering of oil was studied, and the results were compared with those in gas chromatogram. In a 2 1 beaker, 1.5 1 of 3.5% sodium chloride aqueous solution was added, and 300 ml of each crude oil (Murban, Iranian heavy, Minas) was stored on the solution. Gas chromatogram was recorded as follows: The oil sample dissolved in benzene was injected into a column containing Chromosolb W coated with 3% Silicone SE-30. The column temperature was programmed from 40°C to 300°C at 8°C/min. Flame ionization detector was used. Gel permeation chromatogram was recorded as follows: The dehydrated oil sample was dissolved in chloroform and the sample solution was analysed. Polystylene gel HSG-15 and tetrahydrofuran were used as a stationary phase and a mobile phase, respectively. Absorbance of an eluate was measured at 254 nm. The gas chromatogram was changed rapidly with weathering of oil, and this change was mainly caused by an evaporation of low boilingpoint components. In the case of gel permeation chromatogram, although the peak intensity of chromatogram was increased with weathering, the change of profile was very small. It became clear that the gel permeation chromatography with ultra-violet absorption detector was very efficient for discrimination of spilled oil.View full abstractDownload PDF (813K) -
Shingo Matsuoka, Takemi Takano, Takaaki Tamura1978 Volume 27 Issue 12 Pages 777-782
Published: December 05, 1978
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSOne of the purposes of this work is to obtain a complete hydrogenation catalyst free from side-reactions in order to know skeletal structures of small amounts of unsaturated hydrocarbons (C6C8) by means of gas chromatography with a capillary column. The other purpose is to obtain an intermediate catalyst, which causes isomerization of unsaturates through doublebond migration, in order to determine retention times of a large number of unsaturates using a small number of standard samples. An injected sample with hydrogen carrier gas (80 ml/min), passing through pre-column (5 cm long and 0.4 cm ID), is separated by a squalane capillary column and detected by FID. 0.5% Pd-Al2O3 (δ-Al2O3, 5/64'' Sphere) (250 mg, 180°C) satisfies the condition of pre-column complete hydrogenation: 1 μl quantity of sample reaches thermodynamic equilibrium for hydrogenation reactions after passing the pre-column. Side-reaction products are less than 100 ppm. Small constituents in a sample are not lost in the pre-column. Aromatics and their saturated naphthenes equilibrate to nearly equal composition at about 290°C. This phenomenon may be readily available in a distinction of six-membered hydrocarbons. If amount of unsaturates in a sample is small, less than (0.10.01) μl, 0.5% Pd-Chromosorb (250 mg, 100°C) can be used as the complete hydrogenation catalyst with no side-reaction product formation. 0.5% Pd-Chromosorb {(520)mg, 100°C} gives intermediate hydrogenation products for 1μl of unsaturated hydrocarbon. These are doublebond migrated isomers and partially hydrogenated products. Conversion to these products reaches 50 mol%. Retention times are not affected at all by the installation of pre-column (Pd-Al2O3 and-Chromosorb).View full abstractDownload PDF (996K) -
Yusuke UJIHIRA, Kiyoshi NOMURA1978 Volume 27 Issue 12 Pages 782-787
Published: December 05, 1978
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe polished NT-70H steel (Fe: 95.97%, C: 0.56%, diameter:5 cm, thickness:0.5 cm) was immersed in deionized water or in solutions containing (0.250.5) M of chloride, sulfate and nitrate ions. The chemical states of oxidation products of iron on the surface were identified through the analysis of conversion electron Mossbauer spectra (CEMS). GEMS of the steel surface, which had been dipped in deionized water, revealed that γ-FeOOH was formed on the surface. The thickness of γ-FeOOH layer increased with the increase of the duration of dipping. Dissolved oxygen in the solution played an essential role in the oxidation of iron to γ-FeOOH. Oxidation product of iron dipped in the 0.5 M sodium chloride solution was identified as γ-FeOOH. Amorphous paramagnetic iron (III) compound tended to form in the presence of hydrogen peroxide or ammonium ions in the solutions. The increase of alkalinity of the solution up to pH 12 suppressed the oxidation rate and assisted the formation of green rust, which was comfirmed by the appearance of the quadrupole splitting peaks of the green rust. In the 0.25 M sodium sulfate solution, oxidation of the steel surface proceeded slowly and the quadrupole splitting peaks of Fe(OH)2 were seen in the CEMS. The peak intensity of Fe(OH)2 gradually decreased and that of γ-FeOOH increased by the extension of immersion of steel in the solution. Magnetite (Fe3O4) layer was developed beneath the T-Fe0OH layer, when steel was dipped in 0.5 M sodium nitrate solution. However, the peaks of Fe3O4 were not seen on CEMS of steel surface immersed in 0.5 M ammonium nitrate solution. Thus, applying the feasibility of GEMS for the characterization of oxidated compounds of iron on the steel surface formed by the immersion in solutions, the oxidation mechanism of the steel surface was discussed based upon the results of chemical state analyses.View full abstractDownload PDF (992K) -
Akira MURATA, Masanori TOMINAGA, Tetsuo SUZUKI, Motoshi NAKAMURA1978 Volume 27 Issue 12 Pages 788-792
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn the previous paper, the effect of substituents on the fluorescence intensity of the scandium complexes of 5-hydroxychromone and its derivatives had been reported. The present paper describes a similar investigation on the scandium complexes of 5-hydroxyflavone (2-phenyl derivative of 5-hydroxychromone), 5-hydroxyisoflavone (3-phenyl derivative) and their derivatives. All these reagents form the complexes with scandium, which show constant fluorescence intensity when they were extracted from a solution of pH 910 into benzene. Fluorescence of all the complexes of 5-hydroxyflavone derivatives is weaker than that of the complexes of corresponding 5-hydroxychromone derivatives, that is, the phenyl group of 2-position decreases the fluorescence intensity. The introduction of alkyl group (methy<ethyl) into the 2-position and methoxyl group into the 7-position of 5-hydroxyisoflavone greatly increases the fluorescence intensity. The best fluorescent reagent for scandium is 2-ethyl-5-hydroxy-7-methoxyisoflavone and this complex has a maximum emission at 497 nm with an excitation at 377 nm in benzene. An analytical procedure is as follows: To a scandium solution, 5 ml of 2 × 10-3 M methanol solution of reagent, 7.5 ml of methanol and 5 ml of buffer solution (boric acid-sodium hydroxide, 0.25 M boric acid, pH 910) are added, and the mixture is diluted to 25 ml with water. After 30 min, the solution is shaken for 30 s with 10 ml of benzene. The extract is dried over about 1 g of anhydrous sodium sulfate. After 15 min, the fluorescence intensity is measured (365 nm mercury line/430 nm<) against 1μg/ml aqueous solution of sodium fluorescein. The analytical curve is linear up to 6.0μg of scandium. The effect of diverse ions were examined.View full abstractDownload PDF (829K) -
Tamotsu OKUMURA1978 Volume 27 Issue 12 Pages 793-796
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIt was found that the magnitude of electrokinetic (zeta-) potentials between cellulose thin-layer and basic mobile phase, and that of electronic charge density on center atom of inorganic oxyanions were the main controlling factor for thin-layer chromatographic separation of inorganic oxyanions. Organic esters such as steroidal sulfates (cholesteryl 3-O-sulfate, dehydroisoandrosterone 3-O-sulfate) and nitrate (6-nitro-androstenediol diacetate), sugar sulfates (6-monosulfate and 1, 6-disulfate of glucose, galactose and fructose) and sugar phosphates (1-monophosphate, 6-monophosphate and 1, 6-diphosphate of glucose and fructose) have the same chromatographic characteristics as the inorganic oxyanions. In the anion exchange chromatography of adenosine phosphates (5'-AMP, 5'-ADP, 5'-ATP), the phenomena is more evident than in the partition chromatography of the inorganic or organic anions described above. When compared with the original free compounds, hRf values of these organic esters were rather small and it was recognized that the additivity between substituent number (n=13) of sulfate and phosphate residues and difference in hRf values was set up. In the separation of organic oxyanions, the original mobility based on the organic functional groups was also superimposable on that of phosphate or sulfate residues.View full abstractDownload PDF (673K) -
Yoshinori TAKATA, Seiji TAKEUCHI1978 Volume 27 Issue 12 Pages 797-801
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAnion-exchange chromatographic behavior of carboxylic acids in NaCl-HCl-acetone aqueous solution as an eluent was studied. The coulometric detection was applied to detect the acids in the column effluent using pH control column which was prepared by filling about an upper half with Na-form and the other half with H-form resin of weekly acidic cation-exchanger. The pH control column which partially converts weak acid salts to acid forms was set between the separation column and the coulometric detector. The detection was based on the electrochemical reaction of a p-benzoquinone and two protons of acids producing hydroquinone on the working electrode. It was found that the elution of poly carboxylic acids was very much accelerated with increasing the concentration of counter ion and hydrochloric acid in the eluent. However, lower fatty acids of small dissociation constant were little affected by variation of these concentrations. On the other hand, the addition of acetone into the eluent decreased the retention time of all acids, especially the fatty acids. The optimum concentration of acetone was 5% because of its highest column efficiency. Worsening the efficiency of the separation column could be prevented by using highly cross linked anion-exchange resin as a packing material with the eluent econtaing acetoneView full abstractDownload PDF (785K) -
Shigeru IGARASHI1978 Volume 27 Issue 12 Pages 802-803
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA sensitivity of spectrophotometric determination of methanol, as oxidized to formaldehyde with pottassium permanganate-sulfuric acid, was increased by adding an ethanol solution to sample solution. Based on this fact, the following procedure was proposed to the spectrophotometric determination of methanol with chromotropic acid. Add 0.1 ml of 1.5% ethanol, 0.1 ml of 0.25 M sulfuric acid, and 0.2 ml of 5% potassium permanganate solution to 1.0 ml of the test solution containing (115)μg of methanol. Swirl the mixture, and keep it at room temperature for 20 min. Add 0.3 ml of 20% sodium sulfite solution to reduce the excess of permanganate. Swirl the mixture and add slowly 4 ml of 75% sulfuric acid. Add 0.3 ml of 2% aqueous chromotropic acid solution. Heat the mixture in a boiling water bath for 10 min with occasional swirlings. Upon cooling to room temperature, measure the absorbance at 575 nm against the reagent blank. The sensitivity of this procedure was about five times more than that of no ethanol procedure.View full abstractDownload PDF (338K) -
Shigeru IGARASHI1978 Volume 27 Issue 12 Pages 803-806
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAccording to the conventional colorimetric method for 2-propanol it is oxidized to acetone with K2Cr2O7-H2SO4 solution, and the resulted acetone is allowed to be reacted with furfural to form difurfurylidene-acetone. However, a distillation process is unavoidable for this method to get rid of the color of Cr(VI) used as the oxidizing reagent. Therefore, if KMnO4 is substituted for as the oxidizing reagent, more suitable colorimetric determination of 2-propanol should be accomplished, because permanganate will be easily decomposed by sodium sulfite. It was also found that the oxidation reaction of 2-propanol to acetone became accelerated by aldehyde compounds such as acetaldehyde-ammonia ([CH3CH(NH2)2OH]3). Based on these observations, the following procedure was developed for the colorimetric determination of 2-propanol with furfural. Take a sample solution (5 ml) containing (250) μg (CH3)2-CHOH. Add 0.3 ml of 0.25 M sulfuric acid, 0.3 ml of 0.2 w/v% acetaldehyde-ammonia solution, and 0.3 ml of 1 w/v% KMnO4 solution. Leave it at room temperature after swirling the mixture for 60 min. Add 0.5 ml of 1.5 w/v% sodium sulfite solution to destroy an excess of KMnO4. Add 0.5 ml of 1, 2-cyclohexanediamine tetraacetic acid (CyDTA) solution which is prepared by dissolving 2.0 g of CyDTA in 15 ml of 12 w/v% sodium hydroxide solution and diluting the mixture with water to 100 ml. Swirl. Stand for 1 min. Add 1 ml of 12 w/v% sodium hydroxide solution and 0.5 ml of furfural solution which is prepared by dissolving 1.0 ml of furfural in 10 ml of ethanol and then diluting the mixture with water to 100 ml. Swirl the mixture, and leave it at room temperature for 60 min. Add 9 ml of 2:1 sulfuric acid. After standing for 20 min, measure the absorbance at 520 nm against the reagent blank. The calibration curve was linear in the range of (250)μg 2-popanol/5 ml. An absorbance of solution at 520 nm was 0.52 for 40μg 2-propanol/5 ml, the coefficient of variation being 3.2%. Acetone, isobutyl alcohol and isopentyl alcohol yielded a positive interference, while methanol and benzyl alcohols negatively interfered with the determination.View full abstractDownload PDF (664K) -
Hitoshi YOSHIDA, Ichiro HAYASHIDA, Mitsuhiko TAGA, Seiichiro HIKIME1978 Volume 27 Issue 12 Pages 806-809
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSConductometric titration of Zn(II) ion with EDTA in the presence of Cr(III) and tartrate ions was investigated. Although Zn(II) ion forms partially the ternary complex, Zn-Cr-tartrate, with Cr(III) and tartrate ions, the determination of Zn(II) ion is possible without interference with the complex formation. Recommended procedure is as follows; The sample solution of Zn(II) ion containing up to 30 mg of Cr(III) and 360 mg of tartrate ions is transferred into a 200 ml beaker. After adding 2 ml of 3 M acetate buffer solution (pH 5.5), the solution is diluted to 120 ml with water and titrated with 0.1 M EDTA solution at a rate for 0.30 ml per min. The change of conductance is recorded. On the titration curve, two inflection points are always obtained, because of the partial ternary complex formation. Total Zn(II) ion in the solution is determined from the second inflection point. The proposed method allows (620) mg of Zn(II) ion to be determined satisfactorily with the coefficient of variation of less than 0.4%. The first inflection point corresponds to Zn(II) ion which does not form the ternary complex. This method is applied also to the study on the ternary complex formation under various conditions.View full abstractDownload PDF (638K)
- |<
- <
- 1
- >
- >|