BUNSEKI KAGAKU
Print ISSN : 0525-1931
Volume 28, Issue 6
Displaying 1-17 of 17 articles from this issue
  • Yoshihito SUZUKI, Masahide MARUYAMA
    1979 Volume 28 Issue 6 Pages 337-340
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    As a new method of thin layer chromatography (TLC), a thermal reaction thin layer chromatography for the rapid analysis of aromatic amines which were present in synthetic rubber as anti-oxydants is described. The outline of thermal reaction TLC method is as follows. The mixture of 2, 4-dinitrofluorobenzene supported on Celite 545 and synthetic rubber is placed in a glass tube and the temperature is raised from 50 to 300°C at the rate of 4°C/min. The thermal reaction products are carried on by carrier gas (N2-NH3 mixed) and condensed on a TLC plate (20 × 20 cm) which moves slowly as correspond to the temperature raising of furnace. The plate is then developed with petroleum-ether/ethylacetate (4/1, v/v), giving the chromatogram of 2, 4-dinitrophenyl derivatives of amines (2, 4-DNP). The both chromatograms of the 2, 4-DNP of amines obtained from synthetic rubber and standard sample were identical. Therefore, it is possible to measure qualitatively the amines present in synthetic rubber. In addition to this, it was found that the thermal reaction proceeded quantitatively.
    Download PDF (708K)
  • Determination of humic acid and fulvic acid in sediment
    Shozo MATSUDA, Keizo HIRAKI, Yasuharu NISHIKAWA
    1979 Volume 28 Issue 6 Pages 341-346
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    A fluorometric method was described for the simultaneous determination of lignine sulfonate and humic acid. The fluorescence peaks of lignine sulfonate and humic acid due to excitation at 320 nm have intensity maxima at different wavelengths (near 400 nm, 500 nm, respectively). The concentration of lignine sulfonate and humic acid were determined by a dual wavelength procedure from the emission at 400 nm and 500 nm. Fulvic acid in the extracted solution from sediments was also determined by the dual wavelength procedure, using as the reference a standard solution of lignine sulfonate which gave the similar emission peak as fulvic acid. A typical procedure was as follows. Free humic acid and free fulvic acid in sediment {(0.10.5) g} were extracted with 10 ml of a 0.1 N sodium hydroxide solution, and the combined humic acid and combined fulvic acid in the residual material were also extracted with 10 ml of a 0.1 M sodium pyrophosphate solution. Four milliliters of a 0.1 M EDTA solution and 2 ml of 1 M sodium acetate buffer solution were added to the extracted solution, and pH of the solution was adjusted to 9.0 with sodium hydroxide solution. The fluorescence intensity of the solution was measured at 400 nm and 500 nm depending on excitation 320 nm, and calculated by following equation.
    CNaLS = IF400k2' - IF500k2/k1k2' - k2k1', CHA = IF500k1 - IF400k1'/ k1k2' - k2k1'
    where IF400 and IF500 are the relative fluorescence intensitites at the two wavelengths; CNaLS and CHA are concentrations of lignine sulfonate and humic acid; k1 and k1' are the lignine sulfonate constants at 400 nm and 500 nm, and k2 and k2' are the constants for the humic acid at the two wavelengths. This method was applied to sediment samples containing less than 10 ppm of two humic conponents. Precision of the method was studied using a mixed standard solution of lignine sulfonate (5.0 ppm) and humic acid (1.0 ppm), and the recovery was 98% (c.v. 0.6%) and 97% (c.v. 2%), respectively.
    Download PDF (1023K)
  • Mamoru TOMINAGA, Yoshimi UMEZAKI
    1979 Volume 28 Issue 6 Pages 347-351
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    Several metals show severe interferences in the determination of lead and cadmium by graphite furnace atomic absorption spectrometry. To suppress these interferences, the matrix modification was investigated, i.e., the matrix is changed into the harmless form by the addition of proper chemical compound into the graphite furnace. The addition of several ammonium salts was examined for this purpose. The added volume of these ammonium salts solution was 40μl for 20μl of sample solution. In the case of the atomic absorption of lead, the addition of 20% ammonium phosphate solution overcomes the interferences of any of foregin metal ions. In the case of cadmium determination, even the addition of 10% ammonium sulfate solution was effective. This method was applied to the direct determination of lead and cadmium in smelting process water and sea water. Results gave a good agreement with those obtained by flame atomic absorption spectrometry combined with the solvent extraction.
    Download PDF (792K)
  • Fluorimetric analysis with 3-aminothiocarbostyril. I
    Tomohiko YOSHIDA, Toyozo UNO
    1979 Volume 28 Issue 6 Pages 351-355
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    A selective fluorimetric method for the determination of p-benzoquinone(BQ) and 1, 4-naphthoquinone(NQ) with 3-aminothiocarbostyril (ATC) was developed on the basis of the fact that characteristic fluorescence was formed by the reaction of ATC with BQ and with NQ, but no fluorescence with o-benzoquinone and with 1, 2-naphthoquinone. (1) BQ reacts with ATC in a dilute sulfuric acid solution in the presence of a small amount of hydrogen peroxide. The reaction product developes, in an alkaline solution, a yellow green fluorescence which has the excitation maximum at 394 nm and the emission maximum at 530 nm. Fluorescence is linear over the range (0.55.0) μg ml-1. The coefficient of variation is 0.6% (n=10) for 3.0 μg ml-1 of BQ. The recommended procedure is as follows: To 5.0 ml of the test solution are added 2 ml of 60% (w/v) sulfuric acid, 0.1 ml of 0.15% hydrogen peroxide solution, and 0.25 ml of 0.1% ethanolic solution of ATC. The mixture is heated in a glass-stoppered test tube for 30 min in a boiling water bath and cooled to room temperature. The reaction mixture is neutralized with 10% sodium hydroxide, adjusted to pH 12 by the addition of 10 ml of 0.5 M NaOH-0.5 M Na2HPO4 buffer solution, diluted with water to 50.0 ml. The fluorescence intensity of the solution is measured at 530 nm with excitation at 394 nm. (2) NQ reacts with ATC in a dilute sulfuric acid solution. The reaction product developes, in a chloroform solution, a red fluorescence which has excitation maxima at 534 and 564 nm and emission maximum at 610 nm. Fluorescence is linear over the range (0.010.5) μg ml-1. The coefficient of variation is 1.8% (n=10) for 0.2μg ml-1 of NQ. The recommended procedure is as follows : To 5.0 ml of the test solution are added 2 ml of 5% (w/v) sulfuric acid and 2 ml of 0.2% ethanolic solution of ATC. The mixture is heated for 90 min at 75°C, and cooled to room temperature. Ten ml of 10% sodium hydroxide solution is added to the solution and extracted with three 5-ml portions of chloroform. The chloroform layers are combined and diluted with chloroform to 20.0 ml. The fluorescence intensity of the solution is measured at 610 nm with excitation at 564 nm.
    Download PDF (869K)
  • Masaki TACHIBANA, Motohisa FURUSAWA
    1979 Volume 28 Issue 6 Pages 356-360
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    The measurement of the fluorescence intensity of carbazole is interfered with the presence of polynuclear aromatic compounds, such as anthracene and fluoranthene. For the purpose of reducing these interferences, the authors have proposed a method for the fluorometric determination of carbazole. The fluorescence intensity of carbazole could be selectively measured by the addition of sodium methoxide, potassium iodide and methanol to dimethyl sulfoxide (DMSO) solution of the sample. In this method, the influence of the interfering substances could be greatly decreased because the fluorescence of the interfering substances were quenched by potassium iodide and the fluorescence maximum of carbazole was shifted to longer wavelength by the ionization with sodium methoxide. Five milliliters of a sample solution containing less than about 1μg of carbazole in DMSO was transferred into a 10 ml volumetric flask. Then, 1.5 g of potassium iodide and about 3 ml of DMSO were added. Potassium iodide being dissolved, the solution was cooled to room temperature. Exactly 1 ml of 10 mg/ml solution of sodium methoxide in DMSO containing 20 vol.% of methanol was added. The mixture was diluted to 10 ml with DMSO. Carbazole could be determined by measuring the relative fluorescence intensity at 423 nm with excitation at 392 nm. As the standard, 0.125 μg/ml solution of carbazole prepared under identical conditions was used. As the blank, the solution obtained in the same manner as the sample was used. By this method, as far as 50 ng of carbazole in the presence of (511) μg of interfering substances respectively, such as anthracene, fluoranthene, phenanthrene, acridine, acenaphthene, anthraquinone and pyrene could be determined.
    Download PDF (790K)
  • Makiko SUEHIRO, Masahiro IIO, Dale A. SCHOELLER, Peter D. KLEIN
    1979 Volume 28 Issue 6 Pages 361-366
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    13CO2 in exhaled CO2 was analyzed by an isotope ratio mass spectrometer equipped with a dual inlet, a magnetic analyzer, and a single collector. Animal experiments using rats were performed for the CO2 samples. 13CO2/12CO2 in the sample was measured and 13C abundance was expressed as δ13C‰(per mil). The CO2 gas of which 13CO2/12CO2 is 0.010920 was used as the reference gas. When the sensitivity of this analysis was defined as the confidence limit in the measurement of small 13C increase, Δ13C, it was calculated to be 3.8‰. When the accuracy for the determination of Δ13C was defined as the relative deviation of the Δ13C values, it was calculated to be 1.3 ‰/Δ13C. Then if we need to obtain the accuracy with the relative deviation smaller than 5%, more than 26‰13C increase is needed. The comparison study between 14CO2 and 13CO2 analysis was also performed. Rats were given 13C and 14C labeled compounds with same labeled position simultaneously, the labeled CO2 in the breath was collected and analyzed. 14CO2 was measured by the liquid scintillation method. The recoveries of 14CO2 and 13CO2 were, as expected from the sensitivity of the 13CO2 analysis, identical when the 13C increase was more than 5‰. Comparing the sensitivity of 14CO2 and 13CO2 detection, lμCi gave the 14CO2 signals equivalent to those of 13CO2 given by 10 mM 13C. On the basis of these studies, the application of the analytical method to the medical sciences is in progress.
    Download PDF (1014K)
  • Hiroto WATANABE, Nobuo YAMAGUCHI, Hiroaki TANAKA
    1979 Volume 28 Issue 6 Pages 366-370
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    Zinc was extracted with 1-(2-pyridylazo)-2-naphthol, PAN, and polyoxyethylene nonyl phenyl ether with on average 7.5 ethylene oxide units, PONPE-7.5. This is based on the fact that a micellar solution of a non-ionic surfactant separates into two phases above a certain temperature, defined as the cloud point, CP. Zinc in quantities up to 3.0 μg was placed in a certrifuge tube, along with 0.50 g of PAN solution (PAN, 0.040 g : PONPE-7.5, 20 g : water, 80 g) and 1 ml of pH 10.0 carbonate buffer. The mixture was diluted to 80 g with water. On standing this turbid solution (CP, 0°C) at room temperature, a lower phase (about 0.7 ml) rich in PONPE-7.5 separates out from the solution. The zinc chelate of PAN is extracted into the lower phase. The two phases can be separated by centrifuging for 1 min at 9500 rpm. After most of the supernatant solution has been poured off the whole solution in the tube was made up to 2.00 g with 0.5 g of 20% PONPE-20 solution and water. This final solution (CP, 60°C) is clear at room temperature. At the maximum wavelength (555 nm) of the chelate the absorbance was measured. Concentration factors up to 40 can be obtained. When sodium tartrate, triethanolamine, N-(dithiocarboxy)-sarcosine and sodium metaphosphate are used as a masking agent, the method can be applied to the determination of zinc in water.
    Download PDF (836K)
  • Isamu TANAKA, Sadao TAHARA, Takashi OHTSUKI, Kimitaka SATO, Ryutaro MA ...
    1979 Volume 28 Issue 6 Pages 371-376
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    To the aim of application of optical emission spectrometry with an inductively coupled plasma source (ICP) to the analysis for steel samples, it was tried to make clear the most suitable condition for analysis parameters, to make sure the detection limits for the alloy elements, and to apply these results to the analysis of low alloy steel samples. The results obtained are summarized as follows: (1) Output power, torch position, flow rate of coolant gas, sample uptake rate and pre-spraying time are important as the analysis parameters. The most suitable condition of these parameters are 1.6 kW, 16 mm, 18 l/min, 1 ml/min and 20 s, respectively. (2) The detection limits were evaluated with the reproducibility (standard deviation) in the repeated analysis of ten times. The limits for alloy elements in steel are generally smaller than those in flame atomic absorption analysis. High sensitive analysis is possible with ICP source emission spectrometry. (3) In the analysis of 35 kinds of low alloy steel samples, accuracies (σd) are 0.0008 to 0.0065% for 12 kinds of alloy elements such as silicon and manganese. In addition, notice for the analytical operation in the analysis of steel samples was pointed out.
    Download PDF (929K)
  • Toshiaki NOMURA, Masanori ORITA
    1979 Volume 28 Issue 6 Pages 377-379
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    α, β, γ, δ-Tetraphenylporphine trisulfonate (TPPS) reacts with iron(II) to form complex of the 1 : 1 molar ratio between TPPS and iron(II). The complex is stable in the pH range of 3.9 to 4.2 and the apparent stability constant is 7.2 as logK at pH 4.0 and ionic strength 0.010. Iron(II) in the range of (1.09.0) μg/50 ml is determined and the sensitivity is 0.48 ngFe(II) cm-2 for 0.001 absorbance, and the molar absorption coefficient is 1.4 ×105 dm3 mol-1 cm-1. Because iron(III) reacts with TPPS in the presence of L-ascorbic acid as a reductant, iron (II) and (III) are successively determined using L-ascorbic acid. Many cations, such as Mn(II), Co(II), Cu(II), Zn(II), Pd(II), Sn(II), etc. interfere on the equivalent mole of iron(II). Take 10 ml of the sample solution containing (1.09.0) μg of iron(II) into a 50-ml Erlenmeyer flask, and add 5 ml of 0.1 M acetate buffer solution to adjust pH to 3.94.2, and 5 ml of 5×10-5 M TPPS solution. Immerse the flask in a boiling water bath for 150 min and cool to room temperature. Transfer the solution in the flask into a 50-ml measuring flask and dilute to the mark with water. Measure the absorbance at 395 nm against water.
    Download PDF (621K)
  • Hiroshi NISHIDA, Taeko NISHIDA, Toshinori SEGAWA
    1979 Volume 28 Issue 6 Pages 379-382
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    When a mixture of iron(III) and Xylenol Orange (XO), in a 0.1M hydrochloric medium, was heated in the presence of the other cations such as copper(II), only iron(III) was reduced to iron(II) with XO and a red iron(III)-XO complex was faded. By the addition of hydrogen peroxide to this solution, the iron(III)-XO complex was formed again. From the difference of the absorbance of the both solutions, iron was determined. The procedure is as follows: To the sample solution in a test tube, add 1.0 ml of 2.5 M hydrochloric acid and 5.0 ml of 0.2% XO solution. Dilute to 25 ml with water. After heat for 25 min in a boiling water bath and cool to room temperature. Transfer an aliquot of the solution into a cell to use as a reference solution. To the remainder of the solution in the test tube, add 0.1 ml of 30% hydrogen peroxide, and measure the absorbance of this solution at 535 nm against the reference solution. The slope of the calibration curves obtained was decreased in the presence of copper and large amounts of nickel and zinc. In this case, therefore, the amount of iron was obtained by the standard addition method. The other cations did not interfere, but titanium interfered seriously. The precision for the determination of (0.121.2) ppm of iron was found to be (0.68)% as the relative error and (0.78)% as the coefficient of variation.
    Download PDF (805K)
  • Hitoshi YOSHIDA, Isoshi NUKATSUKA, Seiichiro HIKIME
    1979 Volume 28 Issue 6 Pages 382-385
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    The results of the application of capillary tube isotachophoresis technique to some EDTA complexes are shown. The stability constant and the kind of counter ion affect to the PR values (Potential grandient of the leading ion/Potential gradient of the sample ion). Different kinds of electrolyte system were used depending on the pH values of the electrolyte. About (19) μl of 0.01 M EDTA complex solution was introduced into the instrument. The migration current was stabilized at 75 μA. The results obtained indicate that the PR values are mainly governed by the valency of the cations. PR values of the EDTA complexes of IIA elements, which have relatively small stability constants, approached to that of the free EDTA when the pH of the leading electrolyte was lowered. This fact might be due to the gradual dissociation of the complexes. When the counter ion in the leading electrolyte had the complexing ability with central metal of EDTA complexes, the PR values of the complexes decreased. The difference in the PR values of each EDTA complexes is increased by this effect, thereby the separation ability of this method is enhanced. Thus, the separation of bivalent and trivalent metal EDTA complexes were easily performed by this method. The linear relation between square root of molecular weights and PR values was obtained for EDTA complexes of IIB elements.
    Download PDF (676K)
  • Yoshinobu WAKAMATSU
    1979 Volume 28 Issue 6 Pages 385-388
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    A method is described for the spectrophotometric determination of gallium(III), which is based on the extraction of gallium(III)-2-bromo-4, 5-dihydroxyazo-benzene-4'-sulfonate (BDAS) complex into 1-butanol in the presence of 1, 3-diphenylguanidinium(DPG) salt. The extraction species has an absorption maximum at about 495 nm, and a constant absorbance is obtained in the pH range 5.7 to 6.2. The procedure is as follows: To a sample solution containing up to 11μg of gallium(III) in a 50 ml separatory funnel were added 3 ml of a 1.0 ×10-3 M BDAS solution and 5 ml of 0.17 M DPG solution which had been adjusted to pH 5.9 with hydrochloric acid and hexamethylene-tetramine solutions. The solution was diluted with water to 20.0 ml and shaken for 5 min with 10.0 ml of 1-butanol. The absorbance of the organic phase was then measured at 495 nm using the reagent blank as a reference. Under the optimum condition, a linear relationship between the absorbance of the organic phase and the gallium(III) content of the aqueous phase is obtained up to 11μg gallium(III) per 20.0 ml. The molar absorptivity of the extracted species is 5.5 ×104 cm-1 mol-1 1 at 495 nm. Iron(III), indium(III), aluminum(III), titanium(IV), zirconium (IV), tungsten(VI), and molybdenum(VI) interfered with the determination of gallium (III) even when present in equimolar amounts that of gallium(III). The interferences from aluminum and thorium (IV) can be eliminated by the addition of sodium fluoride. The composition of the extracted species is gallium (III) : BDAS : DPG = 1 :2 : 2.
    Download PDF (699K)
  • Toshiaki FUJII
    1979 Volume 28 Issue 6 Pages 388-390
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    The temperature programmed gas chromatography in one column was examined as a new method for the simultaneous separation of nitrogen, oxygen, nitric oxide, nitrous oxide, carbon monoxide, carbon dioxide, sulfur dioxide and water. When the common carrier gas was used for this technique, some ghost peaks were appeared during the temperature raising process from -50°C to 220°C. It was supposed to be due to the impurities, such as nitrogen, oxygen and water in carrier gas, which were identified from their peaks by mass spectrometry. This problem was avoided by removing using a molecular sieve trap in the carrier gas line before its supply to the sample. Operating parameters to complete the separation were as follows; Column: φ 4.0 mm, L 4.0 m, glass column packed with Porapak QS; temperature raising rate: Programmed from to -50°C to 0°C at 6°C/min, and from 0°C to 220°C at 10°C/min; carrier gas: helium, 30 ml/min.
    Download PDF (490K)
  • Naobumi OI, Ko-ichi MORIGUCHI
    1979 Volume 28 Issue 6 Pages 390-392
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    The C=N stretching frequency of some model compounds for acrylonitrile (AN)-styrene (ST) copolymers in dimethylformamide was studied in order to explain the fact that the C=N stretching band of AN units in AN-ST copolymers shifts to higher frequency as the probability for finding the AN-AN bond in AN-ST copolymers increases. The following results have been obtained. (1) The C=N stretching band in mononitriles, CH3(CH2)nCN (3≤n≤9), occurs at the essentially constant frequency {(2242± 0.5)cm-1}. (2) The C=N stretching band in dinitriles, NC(CH2)nCN (5≤n≤8), occurs at the same frequency (2242.5 cm-1), but when n≤4 the band shifts to higher frequency as n decreases. (3) The C=N stretching band in NC(CH2)nCN occurs at higher frequency compared with the band in CH3(CH2)nCN or _??_-(CH2)nCN, when n≤3. These results show that the C=N band shifts to higher frequency due to intramolecular inductive effects of the nitrile groups. Moreover, the noticeable results have also been obtained in other model compounds. (1) The C=N stretching band of 2, 4, 6-tricyanoheptane, the model compound for AN-AN-AN triad, occurs at 2239.5 cm-1 and that of polyacrylonitrile at the essentially same frequency (2239.6 cm-1). (2) The C=N stretching band of 4-cyano-2, 6-diphenylheptane, the model compound for ST-AN-ST triad, occurs at 2234.0 cm-1 and that of AN-ST alternating copolymer at the nearly equal frequency (2234.6 cm-1). In conclusion, the fact that the C=N stretching mode of AN units in AN-ST copolymers is sensitive to the sequence environment and shifts to higher frequency as AN content increases can be reasonably explained by the intramolecular inductive effect of the nitrile groups in the copolymers.
    Download PDF (544K)
  • Naobumi OI, Ko-ichi MORIGUCHI
    1979 Volume 28 Issue 6 Pages 392-394
    Published: June 05, 1979
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    The C=O stretching frequency of some model compouds of methylacrylate (MA)-styrene (ST) copolymers in benzene was studied in order to explain the fact that the C=O stretching band of MA units in MA-ST copolymers shifts to higher frequency as the MA content increases. The following results have been obtained. (1) The C=O stretching band in methyl monocarboxylate, CH3(CH2)nCOOCH3 (2≤n≤8), occurs at the essentially constant frequency {(1740.5±0.3) cm-1}. (2) The C=O stretching band in dimethyl dicarboxylate, CH3OOC(CH2)nCOOCH3 (5≤n≤8), also occurs at the same frequency {(1740.5 ±0.3)cm-1}, but when n≤4 the band shifts to higher frequency as n decreases. (3) The C=O stretching band in CH3OOC(CH2)nCOOCH3 occurs at higher frequency compared with the band in CH3(CH2)nCOOCH3 or _??_-(CH2)nCOOCH3 when n≤3. These results show that the C=O band shifts to higher frequency due to intramolecular inductive effects of the carbonyl groups. Moreover, the noticeable results have also been obtained in other model compounds. (1) The C=O stretching band of 2, 4, 6-tricarbomethoxyheptane, the model compound for MA-MA-MA triad, occurs at 1739.4 cm-1 and that of polymethylacrylate at the essentially same frequency (1739.6 cm-1). (2) The C=O stretching band of 4-carbomethoxy-2, 6-diphenylheptane, the model compound for ST-MA-ST triad, occurs at 1735.0 cm-1 and that of MA-ST alternating copolymer at just the same frequency (1735.0 cm-1). In conclusion, the fact that the carbonyl stretching mode of MA units in MA-ST copolymers is sensitive to the sequence environment and shifts to higher frequency as MA content increases can be reasonably explained by the intramolecular inductive effect of the carbonyl groups in the copolymers.
    Download PDF (535K)
  • Wataru ISHIBASHI, Ryoji KIKUCHI, Kozo YAMAMOTO
    1979 Volume 28 Issue 6 Pages 394-399
    Published: June 05, 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    The direct determination of calcium in solid samples, such as tantalum, ferrotungsten, electrolytic iron and Spex G-4 powders, by atomic absorption spectrometry was studied with a graphite furnace. In comparison with the flame atomization method, the method is free from contamination from the reagents, rapid and easy to operate. Some experimental factors for the determination were tested: (1) the effect of argon carrier gas flow rate on the absorption of calcium, (2) the optimum atomizing temperature, (3) the calibration either by the peak height or by the peak area and (4) the matrix effect. When the peak height was measured, the absorbance signals from the calcium standard solution were not changed by the carier gas flow rate, while the absorption signals from solid samples decreased linearly in proportion to the increase of carrier gas flows. When the peak area used, the higher the carrier gas flow rate, the lower the absorbance of calcium both in the standard solution and the solid samples. The peak height values increased with increasing atomizing temperature, but the integrated values of the absorption spectrum approached a constant value above 2400°C. Calibration curves obtained from the integrated values were linear over 040 ng of calcium, while those obtained from the peak height values were not. Signal profiles for calcium differed according to the states of samples. A large difference came out in the absorbance peaks from ferrotungsten between a dissolved sample and a solid sample. The direct analysis of solid samples for calcium was successful for Spex G-4, tantalum and electrolytic iron, but not for ferrotungsten. The results of the analysis of solutions were generally in good agreement with those obtained for solid samples by peak area measurements. The detection limit for calcium was down to 5 ×10-11 g, and the relative standard deviation was 27%.
    Download PDF (858K)
  • 1979 Volume 28 Issue 6 Pages 400
    Published: 1979
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    Download PDF (76K)
feedback
Top