All issues
Volume 28, Issue 2
Displaying 1-20 of 20 articles from this issue
- |<
- <
- 1
- >
- >|
-
Naobumi OI, Hiroshi TAKEDA, Hiro-o SHIMADA, Osamu HIROAKI1979 Volume 28 Issue 2 Pages 69-72
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSAlthough N-acyl dipeptide esters are useful as the optically active stationary phases for the gas chromatographic separation of amino acid enantiomers, these phases are not very effective for the separation of amine enantiomers, and moreover, their thermally stable range is limited. In order to overcome these disadvantages, we have newly synthesized two s-triazine derivatives of dipeptide esters; N, N'-[2, 4-(6-ethoxy-1, 3, 5-triazine)diyl]-bis-(L-valyl-L-valine isopropyl ester) [I] and N, N'-[2, 4-(6-cyclohexylamino-1, 3, 5-triazine)-diyl]-bis-(L-valyl-L-valine isopropyl ester) [II]. These new phases were able to separate both amino acid and amine enantiomers quite effectively. It was noticed that higher separation factors were obtained on [I] than on the corresponding s-triazine derivatives of amino acid esters, N, N', N″-[2, 4, 6-(1, 3, 5-triazine)-triyl]-tris-(L-valine isopropyl ester) [III]. For example, the separation factors (α) for N-TFA-DL-valine isopropyl ester were 1.055 on [I] and 1.047 on [III] at 110°C, and for N-PFP-dl-α-(1-naphthyl)ethylamine were 1.061 on [I] and 1.039 on [III] at 150°C. [I] and [II] show high thermal stability, and their maximum permissible operation temperatures were about 170°C and 175°C, respectively. Moreover, due to their relatively low melting points {(7172)°C and (103104)°C, respectively}, their columns are effective over a wide range of temperature.View full abstractDownload PDF (551K) -
Takeshi KATO, Tatsuya SASAHARA1979 Volume 28 Issue 2 Pages 73-77
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSIron(II) reacts with 2, 6-diacetylpyridinedioxime (abbreviated as DAPD) in alkaline medium to form a red color complex. The complex has an absorption maximum at 485 nm and shows a constant absorbance against a reagent blank in the alkaline solution of pH 12.5 or above. The calibration curve obeys Beer's law over the concentration range from 0.2 to 7 μg/ml of iron(II) at 485 nm. The molar absorption coefficient of complex is 1.16×104 cm-1 mol-1l. The combining ratio of iron and DAPD in the complex was estimated to be 1:2 by the analytical results of isolated complex and the continuous variation method. The analytical procedure is as follows; To a sample solution containing iron(II), 5 ml of 5×10-3 mol DAPD 50% ethanol solution (containing 1.4 mol hydroxylamine) and 5 ml of 2 N sodium hydroxide solution were added, and the resulted solution was heated gently to boil. After cooling the solution to room temperature under flowing tap water, the solution was transfered to a 50 ml volumetric flask and diluted to the mark with water. The absorbance of the complex was measured at 485 nm against blank solution. The method was applied to the determination of iron in sodium hydroxide, and the analytical result agreed well with 1, 10-phenanthroline method.View full abstractDownload PDF (825K) -
Spectral interference in atomic absorption spectrometry. IIIHidehiro DAIDOJI1979 Volume 28 Issue 2 Pages 77-82
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSAbsorption spectra for some sodium salts such as sodium chloride, hydroxide, nitrate, sulfate and disodium hydrogen phosphate in air-acetylene and argon-hydrogen-air flames were measured in the wavelength range 2000 to 4000 Å. The absorption spectra measured with Hitachi 207 type atomic absorption spectrophotometer. D2 lamp was used as a continuous light source. The absorption spectra in air-acetylene flame were detected NaCl, NaOH, PO and NO molecules as shown in Fig. 1, 2. The absorption spectra of NaCl, NaOH and SO2 were obtained clearly in cool argon-hydrogen flame. The molecular absorption spectra of NaCl and NaOH were absorbed strongly in lean hydrogen flame. The band spectrum of NaCl was measured in (20003000) Å region, and the spectrum of NaOH was measured in (20004000) Å region as shown in Fig. 4. In rich hydrogen flame, the density of atomic sodium was increased because of these molecules were dissociated in the flame.View full abstractDownload PDF (890K) -
Shigeki OHNISHI, Akiko OGAWA, Yasushi NISHIJIMA1979 Volume 28 Issue 2 Pages 82-86
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSHigh speed liquid chromatographic analysis of estradiol(E) and ethinylestradiol(EE) on Nucleosil 5NH2 (10 μm, Macherey-Nagel) and LiChrosorb NH2 (10 μm, E. Merck) was studied. E and EE were separately eluted with the mixed solvent of ethanol and hexane as eluent. The conditions were as follows; column size: 4 mm i.d.×250 mm, detector : fluorescence spectrophotometer (exciting wave length: 280 nm and fluorescence wave length: 305 nm), flow rate: 1.5 ml/min, column temperature: 40 °C, eluent: 6% ethanol/hexane (LiChrosorb NH2 column) and 10% ethanol/hexane (Nucleosil 5NH2 column). The plots of peak hight and area vs. amount of E and EE were linear between 1 to 10 ppm using a fluorescence spectrophotometer. When 10 μl of standard solution of 20% hexane in ethanol was injected to the column, a lowering of column efficiency was not appeared. The averaged recoveries from hair tonic and skin cream ranged from 94.3 to 99.9% and c.v. (%) were 2.62 to 2.04, respectively. This method is very simple and rapid, therefore it is applicable to determine E and EE in cosmetic products at routine analyses.View full abstractDownload PDF (811K) -
Susumu NAKAMURA, Akira KAWASE1979 Volume 28 Issue 2 Pages 86-91
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSThe determination of trace elements in a complex matrix by flame or graphite furnace atomic absorption gives rise to serious background correction problems. Background light losses were found to result from light scattering, molecular absorption and atomic absorption due to the matrix. To solve these problems the elements of interest should be separated from the matrix and/or a correction should be made for background light losses with a continuum light source. This paper dealt with the errors of background correction with a deuterium lamp in atomic absorption spectrophotometry. With a system like the Massmann graphite tube furnace the background absorption changed with time and its distribution was heterogeneous. In this case, the major source of the error was due to the difference in the size of beams and also due to the hollow cathode lamp not being adequately aligned with respect to the deuterium beam. With the system of flame atomic absorption spectrometry, the background absorption was homogeneous and stable. In this case, the major source of the error turned out to result from the stray light caused by the deuterium lamp.View full abstractDownload PDF (1072K) -
Hitoshi KOIZUMI, Yoshihito SUZUKI1979 Volume 28 Issue 2 Pages 92-97
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSApplications of liquid crystal as a liquid phase in liquid-gas chromatography was discussed. It was found that the use of the nematic phase of 4-(p-methyl benzyloxy)benziliden-4'-n-butyl aniline (MBBB) has led to excellent separations of the position isomers pairs of disubstituted benzene derivatives from their mixtures, such as m-, p- and o-xylene; m- and p-chlorotoluene; m-and p-methoxytoluene; and m- and p-dichlorobenzene. MBBB has mp 131.5°C, and (nematic-liquid) transition temperature 147°C. The chromatographic operations were performed on 20% MBBB at 180°C (isotropic liquid). Benzene and 1-butanol were used to charaterize the stationary phase and each was intended to measure a different type of solutesolvent interaction. McReynold's constants obtained from its retention(ΔI) was 154 for benzene, and 186 for 1-butanol, respectively. The linear relation was found between 1/T and log k (k=partition ratio) and the slope of the line is proportional toΔH (the heat of dissolution). The heat of dissolution this obtained was in the range 610 kcal/mol, which is quite resonable for these compounds.View full abstractDownload PDF (959K) -
Photoacoustic spectrometry of solid samples. IYu YOKOYAMA, Nobuo NAKAMURA1979 Volume 28 Issue 2 Pages 97-101
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSPhotoacoustic spectrometer was constructed, by which methods were investigated for measuring the absorption spectrum of solid sample and for determining microamounts of metal. Nickel dimethylglyoxime complex was prepared on filter paper by the technique of spot test. The optimal conditions for preparation of the complex were examined regarding physical properties of filter paper, volume of sample solution, pH of the sample solution and so on. The optimal conditions for photoacoustic signal measurement were examined regarding black standard, chopping frequency of incident radiation and so on. Photoacoustic signal intensity was normalized with respect to signal intensity from black standard to compensate for the wavelength distribution of intensity of incident radiation. The photoacoustic spectrum of solid nickel dimethylglyoxime complex was obtained in the visible wavelength region. The absorption maximum at approximately 540 nm and the increase in absorption towards 410 nm correspond well to the reflectance minima at approximately 545 nm and 400 nm in diffuse reflectance spectrum of the same sample, respectively. The photoacoustic spectrum was different from absorption spectra of the solutions of nickel dimethylglyoxime complex. The calibration curve obtained by plotting normalized signal intensity at 540 nm against nickel amount was linear from 5 to 50 ng.View full abstractDownload PDF (984K) -
Shiro GOHDA, Hideo YAMAZAKI, Yasuharu NISHIKAWA1979 Volume 28 Issue 2 Pages 102-105
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSRadiometric analysis using 65Zn tracer was applied to an indirect quantitative determination of phosphoric acid by precipitating phosphoric acid as ZnNH4PO4. After zinc tracer of known specific activity (A/M) was added to a sample solution, a known amount of Zn (m, m≤M) was precipitated as 65ZnNH4PO4. As phosphoric acid reacts with zinc in equivalent mole ratio, the amount of phosphoric acid in the sample, which is equal to that of zinc, m, can be determined by measuring activity (a) of the precipitate, applying the equation (1). m=(a/A)M……(1) The optimum condition to precipitate ZnNH4PO4 was obtained by setting the pH 57, using p-nitrophenol as an indicator, and by adding 2 or more times as much equivalent weight of zinc against the phosphoric acid. When this process is applied, the coexisting large amount of arsenic(V) gives positive error, while that of calcium(II) and iron(III) negative error. Calcium(II) and iron(III) in the sample solution of 0.1N HCl acidity could be removed using cation exchange resin column {Dowex 50W×8, (100200) mesh, H-form}, and the interference of arsenic(V) could be avoided by reducing it with NH4HSO3 beforehand. More than 1.55mg of phosphorus could be determined by this process. When this method was applied to the determination of phosphorus in monazite as well as of synthetic hydroxyapatite, phosphoric acid in samples could be determined within 1.0% relative standard deviation.View full abstractDownload PDF (684K) -
Kenjiro HAYASHI, Yoshiaki SASAKI, Shoji TAGASHIRA, Tomoko TANAKA, Keik ...1979 Volume 28 Issue 2 Pages 106-110
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSBoth of iron(II) and iron(III) react with potassium benzyl xanthate (potassium O-benzyl dithiocarbonate, Kbex) to form dark brown complexes which are sparingly soluble in water. These complexes were extracted with chloroform and gave the identical absorption spectrum having the absorption maximum at 560 nm. In the presence of Kbex more than 5×10-3 mol dm-3, iron(II) of 3×10-4 mol dm-3 and iron(III) of 4×10-4mol dm-3 were quantitatively extracted from the aqueous solution of pH(57) and pH(34), respectively. The compositions of extracted species were estimated by analysing the relationship between the concentration of bex- and the distribution ratio of iron in the presence of citrate. It may be given as a conclusion that the extracted complex is [Fe(bex)3] in both cases of the extraction of iron(II) and iron(III). According to this conclusion, it was determined that the overall formation constant, partition coefficient, and molar absorption coefficient at 560 nm in chloroform for [Fe(bex)3] were 1013.9, 103.0, and 1.17×103, respectively. The complexes synthesized from iron(II) and iron(III) were highly soluble in chloroform and gave the identical absorption spectrum. This spectrum agreed with that of the extracted complex. Iron contents of synthesized complexes were in agreement with that of [Fe(bex)3]. From these results, it may be said that the composition of the sparingly soluble ironbenzyl xanthate complex formed in water is [Fe(bex)3].View full abstractDownload PDF (890K) -
Mitsuhiko TAGA, Chizuko SATO, Hitoshi YOSHIDA, Seiichiro HIKIME1979 Volume 28 Issue 2 Pages 111-115
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA trace of manganese was extracted as ion-pair with 2-[2-(hydroxyimino)-1-methylpropylidene]-N-phenyl-hydrazinecarbothioamide (PBTOH2)-tetra-butylammonium ion(Bu4N+) into methyl isobutylketone(MIBK) and determined by atomic absorption spectrometry(AAS) with air-acetylene flame. PBTOH2 was prepared by the method reported by Cano Pavon et al. and dissolved in dimethylformamide(DMF). Bu4NBr was dissolved in MIBK. The general procedure was as follows: Take an aliquot of sample solution containing up to 10 μg of manganese into a separatory funnel. Add 3 cm3 of 0.4 w/v% PBTOH2-DMF solution and 5 cm3 of ammonia buffer (pH 10) and adjust the total volume of aqueous phase to 25 cm3 with water. Then extract the manganese complex with 10 cm3 of 1 w/v% Bu4NBr-MIBK solution by shaking for 20 seconds. Determine the extracted manganese complex by AAS. Extracted species was stable in MIBK for at least 6 hours. The equilibrium shift method indicated that the composition of extracted species was Mn: PBTOH2 :Bu4N+=1:2:1. The detection limit was 0.012 μg cm-3 for 1% absorbance in organic phase and the relative standard deviation was 1.54% from 16 repeated determinations with 5 μg manganese. Although the coexistence of trace copper or nickel gave negative errors, in the presence of 5 mg of cyanide ion 400 μg of copper or 500 μg of nickel did not interfere to determine 5 μg manganese. The effect of other foreign ions was also investigated. The proposed method was successfully applied to the analysis of steels and tap water.View full abstractDownload PDF (722K) -
Fumiaki GOSHIMA, Fumie ISHINO1979 Volume 28 Issue 2 Pages 116-118
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSColor reactions of 20 amino acids on silica gel thin layer with ninhydrin dissolved in sulfuric acid were studied. The procedure is as follows: A sample solution was prepared by dissolving 5 mg of each amino acids in 1 ml of 0.5 M hydrochloric acid and the spray reagent was made by dissolving 0.1 g of ninhydrin in 10 ml of 1 M sulfuric acid. Five μl, of the test solution was spotted on a thin layer of silica gel (Merck, Type-60). After drying, the plate was sprayed with the ninhydrin reagent and heated at 80°C for 15 min. A characteristic reddish-purple spot was observed when cysteine was present in the test solution. The detection limit was 0.1 μg when 5μl of the sample solution was used. However, other amino acids, except tryptophan (yellow) and hydroxyproline (light brown), gave no color with the reagent. The colored products of tryptophan and hydroxyproline were separated by adding a drop of 6 M acetic acid on the colored spot, while the colored product of cysteine remained at the origin and turned. purple. Therefore, the detection became more sensitive and selective. This method serves as a rapid and convenient spot analysis of cysteine in amino acids mixture.View full abstractDownload PDF (586K) -
Osamu HAMAMOTO, Shunichi UCHIYAMA, Ken NOZAKI, Giichi MUTO1979 Volume 28 Issue 2 Pages 118-121
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe behavior of nitrogen dioxide were studied in ethylenediaminetetraacetato iron(II) {Fe(II)-edta} aqueous solutions at pH 4.2 and pH 8.5. Nitrogen gas including 3.0% of NO2 and the 0.019 mol dm-3 Fe (II)-edta solution of pH 4.2 or pH 8.5 were mixed in a gas cylinder, and the formed nitrosyl complex, Fe(II)NO-edta, was determined by polarography. The conversion rates of Fe(II)NO-edta from NO2 were 0.7 at pH 4.2, and 0.12 at pH 8.5. In the acidic solution, about 30% of absorbed NO2 is changed into some species (probably nitrate ion) which does not form the nitrosyl complex. On the other hand, in the alkaline solution the main product is estimated nitrite ion which does not react with the Fe(II)-edta at this pH value. The conversion rates of Fe(II)NO-edta from NO2 was raised to 0.82 when potassium iodide (0.96 mol dm-3) was added to the acidic solution. For the analysis of nitrogen oxides, the concentration of NO and NO2 can be given respectively by solving simultaneous equations shown as follows.
Ca=CNO+0.82 CNO2
Cb=CNO+0.12 CNO2
where Ca and Cb are concentrations of Fe(II)NO-edta determined in the acidic solution containing potassium iodide and the alkaline solution respectively, and CNO and CNO2 are concentrations of NO and NO2 to be determined.View full abstractDownload PDF (655K) -
Organic elemental microanalysis by colorimetric method. IVWataru MACHIDA, Satori UTSUMI1979 Volume 28 Issue 2 Pages 121-123
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA simple spectrophotometric method for the microdetermination of bromine in organic halogenocompounds has been proposed. A sample containing bromine is burnt in a flask filled with oxygen, and the gas formed is absorbed in a definite volume of water. The solution is heated to nearly boiling and then cooled with tap water. An aliquot of the solution is taken in a separatory funnel, and mixed with a sulfuric acid and a potassium permanganate solution, whereby bromide in the solution is quantitatively oxidized to bromine, which can be extracted with carbon tetrachloride. To the organic phase are added water, ferric ammonium sulfate-nitric acid solution and methanolic mercuric thiocyanate solution. The mixture is then shaken vigorously for 1 min. The absorbance of colored aqueous phase is measured at 460 nm against distilled water. According to the present method the bromine ranging from 3.75 to 62.50% in organic halogenocompounds can be determined with a reasonably high accuracy of ±0.3%, comparable with those attainable usually in organic elementary microanalysis. Chlorine and iodine do not interfere with the determination of bromine.View full abstractDownload PDF (469K) -
Shinichi SAITO1979 Volume 28 Issue 2 Pages 123-124
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe relation between the degree of vacuum and the effectiveness of the sublimatographic separation was investigated. Using a vacuum system equipped with a leak valve capable of varying the pressure from 0.001 to 1.5 mmHg and of keeping it at constant, the VCP (vacuum condensing point)-pressure curves for anthracene and anthraquinone were obtained at a constant heating temperature (150°C and 165°C). From the results, it was found that the degree of vacuum is an important parameter for the sublimatographic separation.View full abstractDownload PDF (300K) -
Naobumi OI, Osamu HIROAKI, Hiro-o SHIMADA1979 Volume 28 Issue 2 Pages 125-127
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSIt is well known that N-acyl dipeptide esters are the useful optically active stationary phases for gas chromatographic separation of amino acid enantiomers, but N-acyl tripeptide esters give only smaller separation factors compared with the corresponding N-acyl dipeptide ester phases although tripeptide derivatives contain a longer peptide chain than dipeptide derivatives. In order to investigate the effect of extending the peptide chain in optically active stationary phases containing a s-triazine ring, we prepared the new s-triazine derivative of tripeptide ester, N, N'-[2, 4-(6-ethoxy-1, 3, 5-triazine)diyl]-bis-(L-valyl-L-valyl-L-valine isopropyl ester) [I]. It was found that this new compound has more excellent property in relation to enantiomer separation (amino acid and amine) compared with the corresponding s-triazine derivative of dipeptide ester, N, N'-[2, 4-(6-ethoxy-1, 3, 5-triazine)diyl]-bis-(L-valyl-L-valine isopropyl ester) [II]. For example, the separation factors for N-TFAD-L-methionine isopropyl ester are 1.089 on [I] and 1.029 on [II] at 150°C, and for N-TFA-dl-α-(1-naphthyl)ethylamine are 1.072 on [I] and 1.044 on [II] at 160°C. On the other hand, the maximum permissible operating temperature of this new stationary phase with an open tubular glass column (about 200°C) is considerably higher than those of all published optically active stationary phases. For example, in the isothermal mode at 200°C, N, N'-di-PFP-DL-lysine isopropyl ester was separated within 15 min on a 34 m column.View full abstractDownload PDF (449K) -
Masakazu DEGUCHI, Toshifumi MASUMOTO, Kiyotoshi MORISIGE, Itsuo OKUMUR ...1979 Volume 28 Issue 2 Pages 127-130
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA method for the determination of aluminum in iron and steel was studied, using 2, 4-dihydroxybenzaldehyde-semicarbazone (DHBS) as a fluorometric reagent. One gram of the sample was dissolved by heating with 20 ml of sulfuric acid (1+9) and several drops of hydrogen peroxide (3 w/v%). The solution obtained was filtered through filter paper (No. 5C), and the residue was washed with warm sulfuric acid (2+100). The filtrate and washings were used for the following procedure. The residue was fused with 2 g of potassium pyrosulfate in a platinum crucible, and the melt was dissolved in the above filtrate and washings. After the solution was diluted to 100 ml with water, interfering elements were removed by electrolysis with mercury cathode. The solution was made up to 250 ml with water, from which a (0.11.0) ml portion was transferred into a 25 ml measuring flask, and diluted to 10 ml with water. Two milliliters of 0.1% DHBS solution in DMF and 2.0 ml of 20 w/v% ammonium acetate solution were added. The pH of the solution was adjusted to 5.4±0.1 with 1 N ammonia water, and diluted to the mark with water. The fluorescence intensity was measured with primary (UV-D1) and secondary filter (420 nm interference filter). No appreciable interference was caused by other impurities likely to be present in iron and steel. The accuracy of the procedure was checked by J.S.S. samples. The proposed method was applicable to the determination of aluminum above 0.001% in iron and steel.View full abstractDownload PDF (773K) -
Motohisa FURUSAWA, Masaki TACHIBANA, Sumiko YAMADA, Yoshinori ISHIDA1979 Volume 28 Issue 2 Pages 130-132
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSCarbazole can be determined spectrophotometrically by the color development with 3-methyl-2-benzothiazolinone hydrazone (MBTH). However, this method is difficult to be applied to the determination of small amounts of carbazole in organic substances because the color development is carried out in methanol-water medium. Therefore, chromatographic separation of carbazole from the organic matrix was studied for the application of the MBTH method. Ten milliliters of ο-dichlorobenzene solution of the sample was passed through an alumina column (6φ×50 mm), followed by 10 ml of ο-dichlorobenzene. The column was washed with 5 ml of pentane. Then, carbazole was eluted with 6 ml of methanol. Five milliliters of 2% solution of ferric chloride in 0.8 M hydrochloric acid was added to the effluent. After the pentane was removed from the solution by evaporation, 5 ml of aqueous solution of MBTH (0.4%) was added. The solution was allowed to stand for 30 min at 25°C, and diluted to 25 ml with the mixture of concentrated hydrochloric acid and methanol (1:1). After standing the solution for 10 minutes, the absorbance was measured at 580 nm against the blank obtained in the same conditions as the sample using 10 ml of ο-dichlorobenzene. By this method, 0.004% of carbazole in anthracene, phenanthrene, dibenzofuran and fluorene were determined.View full abstractDownload PDF (529K) -
Minoru HOSOYA, Koichi TOZAWA, Mikio ISHIKURO1979 Volume 28 Issue 2 Pages T1-T5
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSAn improvement of steam distillation apparatus for the determination of nitrogen in iron and steel by means of acid dissolution method was accomplished. The apparatus consisted of three parts, a steam generation flask, a distillation tower being equipped with sample solution flask and a water cooling tube. The steam generator and the sample solution flasks commonly used had been a round-bottom type flask, but a pumpkin type flask was replaced in order to increase the distillation efficiency in this experiment. The distillation tower was made up with a triplicate tube. The steam from the generator was blowed into the sample solution through the most inside tube. The evolved gas from the sample solution was heated during its rise through the space between above-mentioned tube and the outer one. Then, the evolved gas was aircooled and condensed at the wall of the most outside tube. The distillation recovery of ca. 100% for nitrogen was obtained with 150 ml of distillate for ca. 8 min distillation time. The coefficient of variation was ca. 1% for 500 μg of nitrogen in standard solution.View full abstractDownload PDF (829K) -
Jun YAMAMOTO, Kiyosumi HASHIMOTO, Hisakatsu HATANAKA, Yoshio KANEDA, M ...1979 Volume 28 Issue 2 Pages T5-T9
Published: February 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSFor the routine analysis of treated and untreated city waters for nitrate, use of coppered cadmium column was tested to facilitate the rapid reduction of nitrate and the subsequent determination. As an activation procedure for used columns treatment of the column (once a day) with a mixture of hydrochloric acid [10-4 M]-EDTA(disodium salt) [0.08%] turned out to be effective enough to permit the subsequent 5 runs of the reduction process. Repeated five determinations of respective 4 and 20 μg NO3-N were accomplished in this way with the accuracy of 88 to 105%, the precision being also comparable with those attainable by the conventional salicylic acid method. We used 10 columns simultaneously, thus accomplishing 50 determinations of nitrate a day. With respect to the removal of cadmium and copper ions released in laboratory waste waters, several methods were examined. Coprecipitation with ferric hydroxide best functioned for this purpose. When the effluent contained EDTA as well as the heavy metals, sulfide precipitation in 0.2 N hydrochloric acid media proved to be effective, but a treatment involving the destruction of EDTA with permanganate and the subsequent coprecipitation with ferric hydroxide was more attractive, because of its simplicity and effectiveness. Whichever methods are applied, they allowed the level of heavy metals after the treatment to decrease down to the permissible concentration in the waste in Japan (Cd 0.1 ppm, Cu 3.0 ppm).View full abstractDownload PDF (841K) -
Kazuo HIIRO1979 Volume 28 Issue 2 Pages T9-T12
Published: February 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSRound robin tests were carried out by the members of Association for Environmental Analysis in Osaka to have an idea about the precision of the spectrophotometric method for the determination of chromium in waste water by a JIS method. Three kinds of synthetic waste water samples containing various co-existing substances were prepared. The diphenylcarbazide spectrophotometric method prescribed in JIS K 0102-1974 was adopted for the determination of total chromium in these samples. At first, Sample I was distributed to the laboratories and 74 data were collected. The mean value of the 74 data was 1.92 mg/l and the coefficient of variation was 14.0%. Second, Sample II containing a large amount of co-existing substances was analyzed. Decomposition of organic substances by either nitric-sulfuric acids or nitric-perchloric acids and separation of iron by cupferron-chloroform extraction were involved prior to the final determination. The coefficient of variation of 22.2% was obtained. Lower results were obtained when the absorbance of color-developed solution was high, exceeding 0.4. Third, Sample III which contained the same co-existing substances as Sample II was analyzed principally in the same manner as for the Sample II, but the details of analytical procedure was rigorously specified in all its aspect. The coefficient of variation of 19.5% came out, indicating that nothing gained in precision. It is difficult to get better than 20% of the coefficient of variation for the determination of total chromium in waste water containing a large amount of co-existing substances by the diphenylcarbazide spectrophotometric method prescribed in JIS K 0102-1974.View full abstractDownload PDF (786K)
- |<
- <
- 1
- >
- >|