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Volume 29, Issue 10
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Katsuaki KAMETANI, Hitomi KAWAKAMI1980 Volume 29 Issue 10 Pages 651-654
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe determination of iodine in plant materials was examined by use of chromium trioxide as an oxidant in wet digestion followed by the distillation of iodine reduced from iodate in the presence of phosphorous acid as a reductant. The recommended procedure was as follows: 1 g of dried seaweeds was decomposed to carbon dioxide by heating with 5 g of chromium trioxide and 20 ml of sulfuric acid in a flask, and the contents was heated to 220 °C to decompose the excess chromium trioxide to tervalent chromium. After cooling the contents of the flask in air, iodate was reduced to iodine by phosphorous acid and then iodine produced was distilled in 10 ml of 10 % sodium hydroxide solution. At the distillation stage, 2 g of phosphorous acid was used with a small amount of sodium nitrate, because nitrous acid produced from nitrate ion in the presence of phosphorous acid accelerated the distillation of iodine. By the results of experiments using 125I as a tracer, the recovery of iodine from dried seaweeds (1 g) was found to be (9799)%.View full abstractDownload PDF (673K) -
Determination of bismuth in a copper metal standard sample by using differential pulse polarographic methodShinichi ITO, Toshio MATSUDA, Toyoshi NAGAI1980 Volume 29 Issue 10 Pages 655-659
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIndividual adsorption of bismuth and copper on hydrous lead dioxide was investigated. Using differential pulse polarographic (d.p.p.) method to determine the metal ion concentrations before and after adsorption, the effects of hydrogen ion and metal ion concentrations and stirring time on the adsorption were evaluated. In acidic solution (pH 12), about 100 % adsorption of bismuth (0.4 mg) and about 0 % adsorption of copper (0.1 mg) on hydrous lead dioxide (HLD, 0.12 g calculated as PbO2·2 H2O) were observed with stirring from one to five hours. The adsorption capacity of HLD to bismuth was about 0.02 g Bi/g HLD. And then the possibility of separating bismuth {(5400) μg} from the solution (500 ml) containing copper (<30 g) by the coprecipitation was investigated. HLD collecting bismuth was dissolved with sodium oxalate, followed by addition of the supporting electrolyte containing sodium citrate, ethylenediaminetetraacetic acid and potassium nitrate. The solution was adjusted to pH 5.05.5 and filled up to 50 ml. Bismuth in the solution was analyzed by using d.p.p. method. The recovery of bismuth was about 100 % without interference from much copper and other coexistent elements, which were As(III), As(V), Sb(III), Sb(V), Fe(III) and Sn(II). This method was applied for the determination of bismuth in a copper metal standard sample, and bismuth amount shown in Table 3 was obtained. From these results, bismuth amount in the order of 10-5 % in a copper metal could be determined without laborious procedures.View full abstractDownload PDF (901K) -
Sachiko SAKURA, Norio ICHINOSE, Nobuo SAKURAI, Gen P. SATO1980 Volume 29 Issue 10 Pages 659-663
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe response of an Orion Lead Electrode 94-82A at 10.0 °C, 25.0 °C, 35.0 °C, 45.0 °C and 50.0 °C(± 0.05 °C) was examined in aqueous 0.1 mol dm-3 KNO3 systems containing alcohols (methanol, ethanol, 1-propanol, ethylene glycol and glycerol). The results were conveniently analyzed by means of a new type of plot in which (2F/2.303 RT) x (E-E_??_) is plotted against log([Pb2+]/c_??_), where E is the potential of the electrode when lead ion concentration is [Pb2+], E_??_ is the potential observed ([Pb2+]=c_??_), and the other symbols have their usual meanings. The advantage of this plot is that it gives a straight line with a slope of 1 passing through the origin when the response is nernstian irrespective of temperature and junction potential, if c_??_ is rightly chosen. In the present case the value of c_??_ was 10-3 mol dm-3. At lead ion concentrations ranging between 1 and 10 mmol dm-3 the response was nernstian in every case. At concentrations lower than a certain limit, which was around (10-410-5) mol dm-3 in the majority of cases, the magnitude |E-E_??_| became smaller than the ideal response. Some samples of 1-propanol contained unknown impurities that interfered with the response of the electrode.View full abstractDownload PDF (927K) -
Minoru CHIBA, Tsutomu ANDO1980 Volume 29 Issue 10 Pages 663-669
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSSilicon carbide and nitride have been attracting a special attention as heat-resisting materials in relation with the energy problem. The oxygen in these materials is considered to be related with their thermal-shock-resisting ability. If ordinary methods are employed for the analysis of the oxygen in such materials that contain silicon as a matrix element or as a major constituent, there arise many difficult problems yet to be solved. It is expected, however, that these material can be analyzed rather rapidly, non-destructively and accurately by the 14 MeV neutron activation analysis if a proper consideration is given to the random sum of γ-rays from 28Al produced by the 28Si (n, p) reaction. This becomes appreciable when a large amount of the sample and/or high 14 MeV neutron flux are used in order to increase the sensitivity. The relation between the saturation activity, A∞ (nf σ), and the random sum counting rate was studied. The random sum of the 28Al γ-rays themselves must be taken into consideration when the A∞ value is high. The apparent half life of the random sum counts was calculated as 69.3 s, and accurate decay analyses of γ-rays were obtained by using this half life as the additional factor. The A∞ value must be kept less than 1.2 × 105 s-1 so as to avoid the fatal interference caused by the triple random sum of 28Al. The external standard method was adopted. By the present method, oxygen contents were determined to be (0.061.40) % for 20 kinds of silicon samples, 20.0 % for a carbide sample and (0.943.05) % for 13 kinds of nitride samples.View full abstractDownload PDF (1200K) -
I. Cation exchange chromatographyMasuo UMINO, Katsuo KOMIYA, Hideo WATANABE1980 Volume 29 Issue 10 Pages 670-674
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe elution behavior of amino acids, dipeptide, and metabolites of catecholamines or tryptophan was studied by cation exchange chromatography with new types of cation exchangers. Two kinds of cation exchangers (IEX-530 CM and IEX-510 SP) were respectively prepared by binding carboxymethyl and sulfopropyl group onto the surface of hydrophilic packings (TSK-GEL G2000SW; Toyo Soda Manufacturing Co.) for high performance aqueous gel permeation chromatography. These new types of exchangers had no adsorption of hydrophilic compounds and showed no volume change by pH and the salt or organic solvent concentrations in the same manner as the original packings which were prepared by chemical treatment of pore controlled silica support. These exchangers were applied to the separation of low molecular weight compounds. By the addition of acetonitrile to the eluent (phosphate buffer), the best separations were attained for catecholamines and their metabolites by using the exchanger IEX-510 SP and for tryptophan metabolites by the exchanger IEX-530 CM.View full abstractDownload PDF (780K) -
Kichinosuke HIROKAWA, Kunio TAKADA1980 Volume 29 Issue 10 Pages 675-680
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSGraphite cup cuvette by electrothermal heating was used as atomizer. A very small sample (less than 500 μg) was put into the cuvette one by one, and each sample was initially heated at 1200 °C for 4 s, subsequently atomized at 1830 °C for 10 s in argon atmosphere (argon flow rate, 2 l/min). Background absorption was corrected with a deuterium arc lamp. Since the atomic absorption signal of lead was composed of a small pre-peak and a large main peak, the absorption intensity of lead was determined from the area of these two peaks. Absorption intensity was directly proportional to the lead content (010 ng). As the majority of the principal constituent of the sample was left in the cuvette, great quantities of residues reduced the absorption intensity of lead. In the analysis of steel samples, the absorption intensity of lead was not affected by residues in the cuvette, when the total amount of the samples inserted in the cuvette was in a range of 0 to 8.5 mg. Therefore, repeating examinations of 70 to 80 samples were possible by using one cuvette. In the analysis of copper and copper alloy samples, the absorption intensity of lead decreased when the total amount of the samples inserted in the cuvette was above 2 mg to 2.5 mg. Therefore, repeating examinations of copper or copper alloy samples were possible for 20 times. The range of the lead content to be determined by this method was 0.00003 % to 0.0064 %. The relative standard deviations of the lead determinations were 5.9%, 6.4 % and 4.3 % for 0.001 % of lead in low alloy steel (n=14), 0.0011 % in copper (n=7) and 0.0029 % in nickel-silver (n=5), respectively. These good repeatabilities seem to suggest that the absorption intensity of lead was not affected by sample form, as an analytical sample was a very small amount. The detection limit (corresponds to the three times of the standard deviation of the background) was 0.017 ng.This value corresponds to a lead content of 3.4 × 10-6 %, when the amount of the sample was 500μg.View full abstractDownload PDF (1009K) -
Tokuo SHIMIZU, Toshiaki HIYAMA, Yoshio SHIJO, Kaoru SAKAI1980 Volume 29 Issue 10 Pages 680-685
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe ppb order of total chromium in human urine was determined by graphite furnace atomic absorption spectrometry after the following pretreatments. Water-soluble inorganic salts in human urine such as sodium chloride were removed by a coprecipitation method. Chromium (VI) which is not collected by the ferric hydroxide coprecipitation method was reduced to chromium(III) by L-ascorbic acid and was coprecipitated with ferric hydroxide at pH 10. After aging for 30 min, the precipitate was filtered with a 0.45μm millipore filter. Coprecipitated organic materials such as protein were digested with nitric acid-hydrogen peroxide for 90 min. Since the analytical line of chromium is 357.9 nm, correction of the background absorption by the coprecipitated inorganic salts was made by using a higher-brilliant thermal cathode type deuterium lamp instead of the conventional deuterium lamps even in the measurements in the visible region. The coefficient of variation was 0.97 % at 5 ppb chromium in synthetic urine (n=7) and 3.30 % in 24 h human urine (n=4). The ppb order of total chromium was determined for the urine of 8 people, and satisfactory results were obtained.View full abstractDownload PDF (965K) -
Tokuo SHIMIZU, Yoshio SHIJO, Kaoru SAKAI1980 Volume 29 Issue 10 Pages 685-689
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSTrace amounts of vanadium were determined by graphite furnace atomic absorption spectrometry using the pyrolytic graphite coated tube after vanadium-4-(2-pyridylazo)resorcinol (PAR) extraction with chloroform. The pyrolytic graphite coated tubes were made in argon atmosphere containing (1020) % volume of methane by heating the conventional tubes up to 2200 °C for (23) min. The sensitivity for vanadium increased (1020) fold by using the coated tube, and the useful lifetime of the tube was greatly extended. In the extraction procedure, trans-1, 2-cyclohexanediamine-N, N, N', N'-tetraacetic acid (CyDTA) was used as a masking agent for interfering metals, but Na, Mg, Al, Fe interfered considerably when their amounts were over 5000 fold of vanadium. Airborne particulates were collected on a glass fiber filter by a high-volume air sampler for 24 h. A part of the filter was digested with HNO3 and H2O2 by heating. After filtration the filtrate was diluted to 25 ml or 50 ml with water in a volumetric flask. Petroleum samples were ashed in the presence of H2SO4 at 600°C. The ash was dissolved in HNO3 and diluted to 50 ml or 100 ml with water. An aliquot of these solutions was used to the determination of vanadium after oxidizing the vanadium to vanadium(V) with KMnO4 in the presence of H2SO4, and satisfactory results were obtained.View full abstractDownload PDF (817K) -
Determination of antimonyTomihisa KAMBARA, Junsuke SUZUKI, Hiroe YOSHIOKA, Yoshio WATANABE1980 Volume 29 Issue 10 Pages 690-693
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe oxidation of Sb(III) in hydrochloric acid media with potassium bromate was studied by using the radiometric titration method in combination with the N- benzoyl-N- phenylhydroxylamine (BPHA) extraction. In the titration the standard series method was used. From the relation of the titration error and the acid concentration, the acid concentration ranges of (2.53.0) M were found to be optimum for the oxidation of Sb(III) in the presence of Zn(II) when Sb(III) amounts are of the order of a few μg. The present radiometric titration method was applied to the analysis of metallic zinc. The antimony in metallic zinc was determined by the standard addition method. After the dissolution of metallic zinc with HCl+H2O2 mixed solution, all Sb(V) were completely reduced to Sb(III) by bubbling SO2 gas through the acid solution, and the coexisting As(III) was removed by the benzene extraction. Definite amounts of the zinc sample thus prepared were taken out into a series of test tubes containing 125Sb(III) tracer and known amounts of Sb(III), and then varying amounts of potassium bromate were added. After the separation of Sb(III) and Sb(V) by the BPHA extraction, the activities of the Sb(V) were counted by a scintillation counter. From the titration curves thus obtained the amounts of antimony were determined. By the present method the determination of as small as 1 μg antimony in metallic zinc was accomplished with good accuracy and precission, without separation of the matrix elements.View full abstractDownload PDF (665K) -
Masahiro KANAI, Tadashi KIKUCHI, Keiichi FURUYA1980 Volume 29 Issue 10 Pages 694-698
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA kinetic energy ion mass analyzer connected with a vacuum fusion furnace developed by the authors{Bunseki Kagaku, 27, 701 (1978)} was used for the simultaneous measurement of nitrogen and carbon monoxide extracted from a sample. A powdered sample (α-Si3N4, AlN, α-Al2O3, α-Fe2O3 or α-SiO2) was enclosed in a graphite or an aluminum-killed steel capsule, and introduced into the graphite crucible in the furnace. The temperature of the crucible was raised at the rate of (25±5) °C/min. The gas extraction curve for the nitride and oxide were prepared from the signal at m/e=14 for nitrogen and at m/e=12 for carbon monoxide. Decomposition temperature of nitride with the steel capsule was found to be lower than that with the graphite capsule (110°C in α-Si3N4, 50°C in AlN), whereas higher was the decomposition temperature of oxide (80 °C in α-Al2O3, 180 °C in α-SiO2) ; however, α-Fe2O3 was decomposed at the same temperature. Reaction mechanisms of nitrides and oxides in vacuum fusion furnace were discussed on the basis of the differences in decomposition temperature; the most probable mechanism for the decomposition of nitrides and oxides in a graphite capsule is proposed to be the reaction of nitrides and oxides with carbon to form the carbides, while that for the decomposition of nitrides with aluminum-killed steel is dissolution of nitrides into iron bath. On the other hand, main reaction of α-Fe2O3 was inferred to be reduction or carbonization by carbon.View full abstractDownload PDF (967K) -
A complete analysis of columbiteKozo NAGASHIMA, Tetsuo TANAKA1980 Volume 29 Issue 10 Pages 699-702
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA complete analysis of columbite (Fe, Mn) (Nb, Ta)2O6-tantalite (Fe, Mn)(Ta, Nb)2O6 series mineral by ICP spectroscopy was made with good reproducibility. The mineral samples were decomposed with a mixture of sulfuric and hydrofluoric acids, and changed to the dil. sulfuric acid solution containing hydrogen peroxide. The suppression effect of sulfuric acid on the emission intensities was minimized by keeping the acid-concentrations of sample and standard solutions the same. Corrections for spectral interferences from coexisting elements were made by subtracting the estimated emission intensities of the interfering elements at the wavelength of the element to be analyzed from the total emission intensity. Procedure. Take about 10 mg sample into a tared Pt crucible. Add 9 ml of sulfuric acid (1:1) and several ml of hydrofuluoric acid. Heat to the strong sulfuric acid fume, cool and weigh the crucible to know the amount of the remaining sulfuric acid. Add calculated amounts of dil. sulfuric acid and hydrogen peroxide solution to adjust the final concentrations to be 5 % and 2 %, respectively. Dilute the solution to 100 ml. Determine the concentrations of elements by the calibration curve technique. Apply the necessary corrections for the interfering elements. Results. Average chemical data from the repeated analyses (8 times) of columbite from Nagatare, Fukuoka are given as follows: FeO 0.167 (25.4); MnO 16.8 (1.06); Nb2O5 34.4 (1.16); Ta2O5 49.2 (1.37); Al2O3 0.170 (32.2); ZrO2 0.229 wt % (4.62 %); total 101.0 wt%, where the coefficient of variations are in the parentheses. The empirical formula is given as (Fe, Mn)0.99(Nb, Ta, Al, Zr)2.01O6.View full abstractDownload PDF (635K) -
Satori UTSUMI, Junichiro YOKOTA, Akinori ISOZAKI1980 Volume 29 Issue 10 Pages 703-707
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSChloride, bromide or iodide ions react with solid silver iodate to liberate iodate ions with the precipitation of silver halide. Triiodide ions are formed by adding potassium iodide and acetic acid to the solution of iodate ion. The present paper deals with a spectrophotometric method for the determination of halide ion based on the measurement of the absorbance of triiodide ions thus formed. The analytical procedure is as follows: Five milliliters of a sample solution containing (0.23.0) × 10-4 M halide ion, 1 ml of 1 M acetic acid and 5 ml of ethanol are added to a centrifuge tube with a stopper, and mixed. After the tube has been allowed to stand in a water bath at 20 °C for about 10 min, 20 mg of silver iodate is added. The mixture is shaken for 3 min and then centrifuged for 3 min at about 3000 rpm. One milliliter of the supernatant solution is transferred to a glass tube with a glass stopper. Then, 7 ml of water, 1 ml of 1 M potassium iodide and 1 ml of 1 M acetic acid are added to the supernatant solution. The absorbance is measured within 10 min at 350 nm with a 10 mm quartz cell against water. For the individual determination in the presence of other halide ions, a suitable separation procedure has been required before this method is applied. The chloride ion in natural waters can be satisfactorily determined by this method, because bromide or iodide ions are not usually present in these samples in such concentrations as would give a serious error. The coefficient of variation of the determination was found to be 1.9 % from 10 repeated measurements with 5.5 × 10-4 M of chloride ion in a town water sample.View full abstractDownload PDF (879K) -
Akinori KATO, Kazutoyo ENDO, Hirotoshi SANO1980 Volume 29 Issue 10 Pages 708-713
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSBy means of the conversion electron Mossbauer spectroscopy (CEMS), we studied surface layers of “tin” plates and tin-coated iron plates corroded by various acids. Transmission Mossbauer spectra and X-ray diffraction patterns were also measured. Metastannic acid was formed, when the “tin” plate was corroded by nitric acid solution. In corrosion by phosphoric acid solution, the X-ray diffractometry revealed the formation of tin(IV) pyrophosphate. In corrosion by various organic acid solutions, the formation of oxides was identified by the 119Sn CEMS, but not by the X-ray diffractometry because of the too thin corrosion layer. In corrosion of tin-coated iron plates, maleic acid, malonic acid, formic acid, and oxalic acid were used. It was determined by CEMS that the corrosion products caused by these acids were tin(IV) oxides, although they could not be identified by the X-ray diffractometry. CEMS also confirmed that the surface of uncorroded tin-coated iron plate was already oxidized by air. Colorimetric determinations of Sn and Fe dissolved from tin-coated iron plates to various acid solutions confirmed that maleic acid had the strongest corrosion effect among the organic acids studied.View full abstractDownload PDF (803K) -
Kunihiko AKATSUKA, Ikuo ATSUYA1980 Volume 29 Issue 10 Pages 714-719
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA simple, rapid and sensitive method for the determination of vanadium is described. The plasma operation conditions employed were as follows: frequency, 2450 MHz; flow rate of plasma-forming gas, 2.5 1/min; flow rate of plasma-sheath gas, 3.0 l/min; field current, 370 mA; anode current, 270 mA; entrance slit width, 30μm; exit slit width, 50μm; pneumatic nebulizer, about 2.5 l/min with water at 2.5 l/min. The V I 437.924 nm line was the most sensitive. Several metals showed enhancing and depressing effects on V I 437.924 nm emission intensity. To suppress these interferences and to improve the sensitivety, the addition of magnesium and iron as radiation buffers was investigated. The results of this study showed that magnesium and iron spectroscopic buffers minimized interference effects, and improved the sensitivity; the detection limit of vanadium was 0.03 ppm. but the calibration curves extended to (0.008100)μg/ml by addition of magnesium. A plateau region in the interference curve by iron was obtained between 7 and 15 mg/ml of iron at the observation position of 1.5 mm from the center of the plasma torch. For the iron concentration with 3 mg/ml of magnesium, only minor changes in spectral intensity were observed in the range of (0.210) mg/ml of iron. Trace amounts of vanadium in steels, soil and air-borne paticulate matter were successfully analyzed without the separation techniques.View full abstractDownload PDF (915K) -
Simple pipetting devices with high operation efficiencyOsamu NARA1980 Volume 29 Issue 10 Pages 720-723
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe simple pipet filling devices, with which (1100) ml pipets can be handled safely, accurately, cleanly, and more quickly, were devised. “Push button pinch clamp type” (Fig. 1): The device is held in the usual way, sealing the top hole, A, with the right index finger. The liquid is automatically sucked up by lightly pushing the button, F, with the thumb to open the pinch clamp, C. Adjusting to the mark and free drainage are performed rapidly by opening the hole, A, in the usual way. “Nozzle valve type” (Fig. 2): The rubber body, D, is pressed lightly to open the nozzle valve, C and the rubber bulb, E, is kept compressed. The device is held in the usual way, sealing the top hole, A. The liquid is automatically sucked up by pressing the body, D. Adjusting to the mark and free drainage are performed in the usual way. “Finger stall type” (Fig. 3): It is quite useful particularly for bacteriological or clinical purposes where each sample should be handled by a different pipet. The device is put on the index finger. The finger is brought down on to the top of the pipet so that the holes in the pad and the pipet coincide. As the pad is pressed down lightly, the nozzle valve, C, is opened and the liquid is automatically sucked up. When the liquid has been sucked up, the finger is moved so that the top of the pipet is sealed with the finger tip. Adjusting to the mark and free drainage are performed in the usual way. Pipetting work by using these devices was performed apparently more effectively than that by sucking by the mouth and they may be recommended for chemists, who daily use pipets, in order to make their experiments more comfortable.View full abstractDownload PDF (627K) -
Itsuo MORI, Yoshikazu FUJITA, Kimiko SAKAGUCHI, Hiroko Tsuji, Takehisa ...1980 Volume 29 Issue 10 Pages 723-726
Published: 1980
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSZinc(II) or cadmium(II) rapidly forms a mixed complex with methylthymol blue(MTB), cetylpyridinium chloride(CPC) and 5-nitroso-8-quinolinol (NO-oxine) {for zinc(II)} or 2-methyl-8-oxine (CH3-oxine) {for cadmium(II)} in a weak basic medium. The absorbance of the cadmium(II) complex at 630 nm (λmax) and that of the zinc(II) complex at 620 nm (λmax) were constant over the pH range from 7.6 to 9.0 for 3 h. The molar ratio of metal, MTB, oxine derivative and CPC in the mixed complex was a 1:1:1:2 by Job's method and the molar ratio method. The calibration curves were linear up to 4.0 μg/ml of cadmium(II) and 3.0 μg /ml of zinc (II). Sandell's sensitivity was 0.005 μg/cm2 for cadmium(II) and 0.003 p.g/cm2 for zinc(II). The recommended procedure is as follows: To a sample solution containing≤40 μg of cadmium(II) {or <30 μg of zinc(II)}, 0.5 ml of 1.0 × 10-2 M CPC, 0.25 ml of 1.0 × 10-2 M NO-oxine (or CH3-oxine solution), 2.0 ml of a borate buffer (pH 8.2) and 1.0 ml of 1.0 × 10-3 M MTB were added. The mixture was diluted to 10.0 ml with water. After the solution was kept at (2025)°C for 5 min, the absorbance was measured at 630 nm {for cadmium(II)} or at 620 nm {for zinc(II)} against a reagent blank. Nickel(II), cyanide, sulfide and thiocyanate interfered. Aluminum (III) and thorium (IV) could be masked with sodium fluoride, and mercury(II) with 1-ascorbic acid.View full abstractDownload PDF (668K) -
Yoshinobu AKADA, Sadako KAWANO, Yaichiro TANASE1980 Volume 29 Issue 10 Pages 727-729
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA rapid and sensitive method using high-performance liquid chromatography was devised for the determination of paeoniflorin and benzoic acid in rat plasma and bovine serum (reference control serum). Separation was achieved within 12 min on a Zorbax CN column, using 0.1 M HClO4(pH 3.5)-CH3CN(9:1, v/v) as an eluant with a Shimadzu LC-2 liquid chromatograph. Recovery in this method was about 100 %. Paeoniflorin and benzoic acid in plasma and serum were extracted with methanol and the extract was applied to the Zorbax CN column. The limit of detection of paeoniflorin and benzoic acid was about 3 μg and 0.6 μg in 1 ml plasma and serum, respectively (S/N ratio, about 3).View full abstractDownload PDF (470K) -
Shigeya SATO, Sumio UCHIKAWA1980 Volume 29 Issue 10 Pages 729-731
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA highly sensitive and selective method for the spectrophotometric determination of boron was developed. Boron reacted with 2, 3-naphthalenediol to form a complex anion extractable into chlorobenzene in the presence of Crystal Violet. Boron can therefore be indirectly determined by measuring the absorbance of the Crystal Violet in the extract at 595 nm. The calibration curve was linear in the range of (1.6 × 10-68 × 10-6) M boron and the apparent molar absorptivity was 1 × 105 l mol-1 cm-1 at 595 nm. The following ions did not interfere even at 400-fold molar ratio to boron; Mg(II), Ca(II), Co(II), Cd(II), Zn(II), Cl-, Br-, I-, NO3- and SO42-. But 400-fold amounts of perchlorate or thiocyanate gave a slightly negative error. Metal ions such as Al(III) and Fe(III) interfered when present in amounts 50-fold that of boron. However, these ions could be tolerated up to about 400-fold molar amounts by adding EDTA to the sample solution at a concentration of 2.0 × 10-2 M.View full abstractDownload PDF (480K) -
Rokuro KURODA, Tadashi MOCHIZUKI, Koichi OGUMA1980 Volume 29 Issue 10 Pages T73-T78
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA flow injection method is described for the spectrophotometric determination of copper in various types of copper-base alloys. The system utilizes either the light absorption of aquacopper(II) ion at 805 nm or the light absorption of colored complex of copper(II) with EDTA (730 nm). Simple dissolution of alloys in nitric acid in the presence of tartaric acid suffices for sample preparation. The procedures have been applied to standard samples of copper-base alloys including several types of brasses, beryllium copper, deoxidized copper, German silver and aluminum bronze. The results obtained agree very satisfactorily with the certified values for these alloys. The precision is better than 0.5 % for the aquacopper(II) ion method. The sampling rate is 17 samples per hour.View full abstractDownload PDF (888K) -
Kamihiko ITSUKI, Iwao NAGAI, Yasushi NAKAMURA, Hiroshi SHIMIZU, Kazuo ...1980 Volume 29 Issue 10 Pages T78-T82
Published: 1980
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSRepresentative samples from each lot of are concentrates are usually preserved in smelters for six months after import. Because sealed envelopes are convenient in practice for transport and storage of a large number of samples, polyvinyl chloride, polyethylene and aluminum foil envelopes were selected for testing their preservation quality. Fourteen laboratories participated in the test using respectively available samples of copper, zinc or lead concentrates, the total number of which amounted to thirty-three. The results show that the analytical metal contents snore or less decrease after storage in those envelopes. Among the envelopes tested the aluminum foil gave the least loss; less than 0.1 % in one month for most of the concentrates and practically none for the copper concentrate even after further five months. Thus, it is concluded that the aluminum foil envelope is preferable to the other polymers.View full abstractDownload PDF (789K)
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