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Volume 30, Issue 7
Displaying 1-19 of 19 articles from this issue
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Hideo IMAI, Hisanobu YOSHIDA, Tsutomu MASUJIMA, Minako YANAGITANI1981 Volume 30 Issue 7 Pages 419-423
Published: July 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA method of determination of trace amounts of hydrogen peroxide was studied by using an electrochemical thin-layer flow cell. The sensitivity and reproducibility of a glassy carbon electrode were improved by anodic oxidation of the electrode surface at 1.4 V for (2030) min in a citrate buffer (pH 3.0). In the cyclic voltammetry (scan rate, 20 mV/s) hydrogen peroxide showed an irreversible 2-electron oxidation peak at 0.88 V vs. Ag/AgCl, 0.1 M KCl electrode at the concentration of 1 mM in a phosphate buffer (pH 7.2), and the peak current was linearly proportional to H2O2 concentration in the range from 10 mM down to 50 μM (1.7 ppm) with inclination of 191μA/mM cm2. More sensitive determination was achieved by using a thin-layer flow cell (cell volume, 2.25μl; flow speed, 8.9 cm/s) at constant applied voltage of 0.95 V. In the concentration range down to 1.47 μM (50 ppb) the working curve showed a good straight line with inclination of 0.192 μA/μM cm2(5.66 μA/ppm cm2), the c.v. values being 0.9 % and 2.4 % for 1.24 ppm and 0.17 ppm, respectively. The detection limit was 30 pmol or 10 ppb. Interference by several anions or oxidative substances was briefly inquired. The method required one minute for each sample in continuous analyses.View full abstractDownload PDF (721K) -
Toshiyuki SAKANO, Tameyuki AMANO1981 Volume 30 Issue 7 Pages 423-427
Published: July 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA fluorometric method has been developed for quantitation of α-[(t-butylamino)methyl]-3-methoxy-4-hydroxybenzylalcohol (I). The method is based on the fluorescence of dansyl-derivative of I after separation on a thin-layer chromatographic plate, and can be applied to the determination of I in the concentration range of (0.040.4) ppm in rat plasma. The procedure is as follows. To 0.5 ml of rat plasma was added 4 ml of ethanol, and the mixture was centrifuged. To 3.5 ml of supernatant was added 1 ml of 0.01 M sodium carbonate and 0.5 ml of 0.5 % dansylchloride acetone solution, and the mixture was reacted for 30 min at room temperature (2225)°C. Then the reaction mixture was condensed to (0.050.1) ml under reduced pressure at 40°C. To the residue was added 2.5 ml of water and 2 ml of ether, and the mixture was shaken for 3 min. After centrifugation, ether extract was poured upon a mini-column packed with silica gel [Merck, (0.050.2) mm, 100 mg], and the column was washed with 8 ml of ether and eluted with 5 ml of acetone. The acetone eluent was evaporated to dryness under reduced pressure at room temperature. The residue was dissolved in 50 μl of acetone and its 10 μl was spotted on the silica gel plate. The plate was developed with a mixed solvent of benzene-triethylamine-acetone (4 : 1 : 1, v/v) for 30 min. After drying the plate for 10 min in air, the fluoresence intensity of dansyl-derivative of I (Rf 0.17) was measured at 520 nm with excitation at 350 nm.View full abstractDownload PDF (615K) -
I. Automatic extraction of tranquilizers from urine samplesYuji NAKAHARA, Minoru AKIYAMA, Kohya YANO1981 Volume 30 Issue 7 Pages 428-432
Published: July 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSFor the analysis of drugs in urine, extraction of small amount of tranquilizers in urine based on a cartridge type reverse phase column (Sep Pak C18) was studied. Sep Pak C18 was tested for extraction by using four phenothiazines and two azepines in urine samples in the concentration of (150)μg/ml and compared with the result of ether extraction. On the Sep Pak C18 extraction, the optimum pH range for phenothiazines is at acidic (pH 5.0), whereas it is at neutral (pH 7.0) in case of azepines. The efficiency for the Sep Pak C18 extraction is (6.520) % higher than that for the ether extraction of tranquilizer in urine. The yield of extraction with a Sep Pak C18 is over 90 %, when chlorpromazine (CPZ) is less than 2 mg in 10 ml of urine. By this method, tranquilizers and their metabolites could be extracted from the urine of a patient who had taken tranquilizers everyday for several months. Three unchanged and five metabolites were identified by GC-MS. The automatic extraction equipment by this method was constructed and the automatic extraction of 15 urine samples containing CPZ was demonstrated.View full abstractDownload PDF (595K) -
Yoshihide ENDO, Noritaka SAKAO1981 Volume 30 Issue 7 Pages 433-438
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSTo enlarge the application of ICP atomic emission spectrometry in steel analysis, internal standard method was studied. Some internal standard elements such as yttrium, cobalt, antimony, cerium, aluminum which are usually uncommon in steels were added to the sample solution. In plasma, each element showed different behavior depending on the analytical conditions but they can be recognized from the analytical lines, whether they are neutral or ionic. Accordingly, the internal standard element must be selected from those behave similarly. When one element was used as an internal standard for the determination of multielement in steel simultaneously, yttrium gave the most satisfactory analytical results. As the internal standard, elements were found more suitable in the order of yttrium, cobalt, antimony, cerium, and aluminum. This method was better than constant time integration method and was applicable to the analysis of all variety of steels.View full abstractDownload PDF (853K) -
Tadao TAMURA, Kazutoshi TANABE, Jiro HIRAISHI, Shinnosuke SAËKI1981 Volume 30 Issue 7 Pages 439-442
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA computer retrieval of infrared spectra by a correlation coefficient method was studied for binary system. Among the IRDC data, 455 spectra were chosen digitized and filed in a YHP 1000 minicomputer. They were normalized so that the strongest absorption band of all spectra had the same intensity with each other. The model for the spectra of the binary system which contains a minor component as an impurity was made by selecting and mixing two components spectra from the file in given ratios. The correlation coefficients between the mixed spectrum and the spectra in the file were calculated for searching the spectrum of each component. The strongest absorption band was used as a sifter before calculating the coefficient in order to reduce noise spectra and shorten a computing time. The result indicates that the small amount of spectroscopic impurities does not affect appreciably the correlation coefficient method and also suggests that it is capable to identify a main component, if it is spectroscopically contained over 70 %.View full abstractDownload PDF (682K) -
Sigeru YOSHIDA, Kayoko ODA, Shingo HIROSE1981 Volume 30 Issue 7 Pages 443-447
Published: July 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSThe determination of some weak basic samples at low concentration (ca. 10-3 M) was investigated photometrically in non-aqueous solvents by back titration. Color change of an indicator in non-aqueous titration is much complicated especially in a dilute solution. Therefore, the color transition of the indicator was calculated by Complementary Tristimulus Colorimetry, which is more suitable to ordinary colorimetry. The calculation of the color transition was useful for the correction of indicator error. Theoretical titration error which was caused by the dissociation in a dilute solution was corrected by the consideration of stoichiometric relationship between the color transition of indicator and the equivalence point. Theoretical titration curve of the titration ratio (a) versus the color transition (φ) was drawn and compared with the experimental data. As typical example of these subjects, some weak basic samples were determined in the presence of excess perchloric acid by using sodium acetate as a titrant and Crystal Violet as an indicator. By the method, 0.198 mg/ml of theophylline, 0.075 mg/ml of glycine were determined accurately (<98.9 %).View full abstractDownload PDF (837K) -
Noriyuki NAKASUKA, Yukari FUJITA, Motoharu TANAKA1981 Volume 30 Issue 7 Pages 448-452
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSChemical equilibria were investigated in a chloroform solution in order to clarify the role of triethanolamine and acetic acid in the colorimetric determination of free fatty acid by using Iwayama's copper reagent. A curvilinear calibration plot was obtained for the Duncombe and modified Itaya-Ui methods. A nonstoichiometric relationship was also observed between the absorbance of copper(II) diethyldithiocarbamate and the quantity of stearic acid. These results were attributed to coextraction of acetic acid with a higher fatty acid. An infra-red spectroscopic analysis revealed the formation of a mixed ligand copper(II) complex with stearic acid and triethanolamine in the organic phase. Addition of this amine(B) to copper(II) caprate {Cu2A4(HA)2} in benzene caused a decrease in absorbances both at 370 nm and at 690 nm, corresponding to the dissociation of the dimeric copper(II) complex into monomeric species. Change in spectra was reasonably explained by the formation of Cu2A4(HA)B and CuA2(HA)3B. It is concluded that triethanolamine was essential and most effective for the extraction procedure in these methods.View full abstractDownload PDF (788K) -
Han Guo HUANG, Keizo HIRAKI, Yasuharu NISHIKAWA1981 Volume 30 Issue 7 Pages 452-460
Published: July 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSSamarium and/or europium β-diketone ternary complexes (TTA-TOPO system, TTA- phen system) show red fluorescence[Sm-Em. max.: 562 nm, 598 nm, 644 nm; Eu-Em. max. : 614 nm], and these complex systems were used for the fluorometric determination of the metal ions. This communication reported the optimum conditions for the fluorometric determination of these ions, and the method was adopted in the simultaneous determination of samarium and europium in xenotime and monazite minerals. From the experimental results on the effect of diverse ions and the extraction pH of the aqueous phase, it became clear that TTA-TOPO hexane method was the best system for the determination of samarium and europium because of the highest fluorescence sensitivity of the ternary complex, and also because the lower extraction pH eliminated the effect of diverse ions. Moreover, the very high detection limit (2 ppb) of Sm was achieved by the use of a red sensitive photomultiplier (R-446UR, Hamamatsu Co. Ltd.), Which was used at 644 nm, and that of Eu (0.02 ppb) at 614 nm. The procedure for the determination of Sm and Eu in mineral was established as follows : The rare earth minerals (xenotime, monazite) sample was treated with hot conc. H2SO4 and twice precipitated with 0.5 mol dm-3 oxalic acid (pH was adjusted to 2.02.2). Then the precipitate was filtered and ignited to give the rare earth oxide. Fifty milligrams of the oxide was dissolved in HCl and diluted with water in order to obtain the solution containing 5 μg cm-3 rare earth oxide. An aliquot of the solution { (1.03.0) cm3} was adjusted to pH 5.5 with sodium acetate and shaken with 1×10-4 mol dm-3 TTA- 2×10-2 mol dm-3 TOPO hexane solution. Then the fluorescence intensity of the organic layer was measured at 644 nm for Sm and 614 nm for Eu. In this procedure, the recovery of Sm and Eu was found to be about 96 %. Several rare earth mineral samples were analysed. Xenotime contained 0.70 % of Sm and 0.004 % of Eu, and monazite contained 1.84 % of Sm and 0.003 % of Eu.View full abstractDownload PDF (1083K) -
Muneo MORISHITA, Masa KATAYANAGI1981 Volume 30 Issue 7 Pages 460-464
Published: July 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESS6-Chloro-3-hydrazino-pyridazine (abbreviated as CHP) formed an insoluble blue-green color precipitate with nickel(II) in alkaline medium. The precipitate dissolved in dioxane showed an absorption maximum at 715 nm and the maximal absorbance was kept constant in the pH range from 8.6 to 11.4, measured against a reagent blank. These findings were applied to the spectrophotometric determination of nickel(II). The recommended procedure is as follows : To 1 ml of 0.1 M CHP solution in a 10 ml volumetric flask add 2 ml of buffer solution {a mixture of dioxane, 10 (w/v) % ammonia and 6 (w/v) % acetic acid (15 : 4 : 6, v/v), pH 9.5; abbreviated as dioxane buffer}, allow to stand for about 5 min, and add 1 ml of the sample solution containing less than 30 μg of nickel (II). Then, dilute to 10 ml with the dioxane buffer and allow to stand for about 10 min. Measure the absorbance at 715 nm against the reagent blank. The calibration curve obeyed Beer's law over the concentration range from 0 to 3μg/ml of nickel(II). The molar absorption coefficient of the complex was 1.86 × 104lcm-1 mol-1. The combining ratio of nickel to CHP in the complex was determined as 1 : 2 by the continuous variation method and the molar ratio method. Among eighteen diverse ions examined here, three of Co(II), Fe(III) and Cu(II) interfered with the determination of Ni(II), cobalt(II) could be removed beforehand by extraction of its 1-nitroso-2-naphtholate into chloroform, and iron(III) into MIBK as tetrachloro-ferate. Copper (II) was effectively masked with thiourea.View full abstractDownload PDF (631K) -
Yukio HIRAI, Norimasa YOZA, Shigeru OHASHI1981 Volume 30 Issue 7 Pages 465-469
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSHigh-pressure flow injection system developed for the determination of ortho- and polyphosphates was applied to the rapid analysis of phosphates in various environmental waters. A strongly acidic molybdenum (V) and molybdenum(VI) reagent was used so that hydrolysis of polyphosphates and color development of the resultant orthophosphate could be achieved simultaneously. A sample solution (0.5 ml) was introduced into a carrier stream of water via a loopvalve sample injector. The carrier stream meets a molybdenum reagent stream from another channel and flows together into a reaction tubing. For complete chemical reaction, the temperature of the reaction tubing (PTFE, 0.5 mm i.d., 1.5 mm o.d., 30 m) was maintained at 140°C. Residence time of the sample in the reaction tubing was about 4 min. The absorbance of heteropoly blue complex was monitored. at 830 nm. Sampling rate was 30 samples/h. Detection limit was 3×10-7 M (0.010 ppm P). The precisions (C.V.) were 4.0 %, 0.3 % and 0.2 % for orthophosphate of 1×10-6 M, 1×10-5 M and 1×10-4 M, respectively. It was found that the flow injection system was effective in determining phosphate in river and well water, but the concentrations of phosphate in sea water and tap water were too low to be monitored by the present system.View full abstractDownload PDF (839K) -
Norihiko HASEGAWA, Etsuko SUGAWARA, Tsutomu KASHIWAGI1981 Volume 30 Issue 7 Pages 470-474
Published: July 05, 1981
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA simple and rapid spectrophotometric determination of small amounts of hydrogen peroxide with peroxidase(POD) and 2, 2'-azinodi[3-ethylbenzthiazoline sulfonate(6)] is described. The oxidized ABTS has absorption peak at 390 nm, 420 nm, 660 nm, and 740 nm in the mixed reagent containing 20 μg/ml of POD and 1 mg/ml of ABTS in 0.1 M phosphate buffer, pH 7.0. The apparent absoptivity at 420 nm is estimated to be 51000 mol-1 cm-1l. Calibration curve obeyed to Beer's law over the range 010μg/ml of hydrogen peroxide and the absorbance was stable at least 2 h. Above 0.18μM of ascorbic acid and 0.9μM of cysteine (final concentration) interfered with the determination of hydrogen peroxide by decreasing the absorbance and sorbitol by increasing the absorbance because of its action as a substrate on POD. The determination procedure given below is simple and rapid. For sample solution containing less than 1 μg/ml of hydrogen peroxide, take 1 ml of sample and add 1.8 ml of mixed reagent, and for those containing above 1 μg/ml of hydrogen peroxide, take (0.10.05) ml of sample and add 2.8 ml of mixed reagent. Measure the absorbance within 2 h. For the determination of hydrogen peroixde in Japanese noodle, take about 5 g of noodle sample, homogenige it in distilled water and then centrifuge at 25000 × g. An aliquot taken from the clear supernatant can be used for the spectrometric determination described above. By this method, 1 ppm of hydrogen peroxide could be determined and the recovery was (90±8.5) %.View full abstractDownload PDF (648K) -
Yukio MINAMI, Toshiyuki MITSUI, Yoshikazu FUJIMURA1981 Volume 30 Issue 7 Pages 475-477
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSAliphatic amines were determined by the complex formation of the amines and SCN- with cobalt followed by atomic absorption spectrometry (AAS).
Amine+4SCN-+Co2+
→(Amine)2[Co(SCN)4]
The recommended procedure is as follows : 0.5 ml of acetone solution of KSCN (32.6 mg/ml) and 0.5 ml of acetone solution of Co(II) {27.91 mg Co(NO3)2-6H2O/ml} are mixed in a 20-ml test tube. The solvent is evaporated on a water bath at 90°C. To this test tube is added 5 ml of benzene solution of each sample {(0.010.13) mg/ml}.After being shaken for 1 min, the benzene solution is dehydrated with anhydrous sodium sulfate. To 1 ml of this solution is added 5 ml of methanol, and finally the cobalt content is measured by AAS. No interferences were observed in the presence of 2.2 molar to 15.6 molar fold of ethanol, diethylether, acetone, acetaldehyde, ethylacetate, acetic acid, nitrobenzene, acetonitrile, or phenol and 1.4 molar fold of diphenylamine.View full abstractDownload PDF (415K) -
Osamu ICHIJO1981 Volume 30 Issue 7 Pages 477-479
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSIron(III) is extracted into methyl isobutyl ketone (MIBK) as a complex with sodium dibenzyldithiocarbamate (DBDTC) in the pH range 2 to 6. The extraction was used for the determination of iron by atomic absorption spectrometry. An aliquot of sample solution containing less than 40 μg of iron is taken, the pH is adjusted to 2 with 6 N sulfuric acid or 6 N ammonia water, and 10 ml of DBDTC solution (0.5 %) is added. The solution is diluted to 50 ml with water, and shaked with 10.0 ml of MIBK for 3 min. The MIBK extract is introduced into an air-acetylene flame and the absorbance is measured at 248.3 nm.By this method, (140) μg of iron could be determined accurately. The tolerance limits for various ions were also determined. The proposed method was applied to the determination of micro amounts of iron in tap waters and waste waters.View full abstractDownload PDF (455K) -
Shigetaka SUZUKI, Toshiyuki HOBO, Katsunori WATABE, Humihiko ISHIKAWA1981 Volume 30 Issue 7 Pages 479-482
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSUreide compounds which have optically active amino acid ester in the structure, give an interesting enantioselective separation depending upon the column temperature when used as stationary phase in gas chromatography. It has not been clearly elucidated by mesophase or solid phase of the ureide, where a good enantiomer separation can be effected. In this work the retention behavior of three racemic amino acids on a ureide {carbonyl-bis-L-valine isopropyl ester} has been investigated. The retention times at various column temperatures of 80°C to 120°C were measured. And the correlation between logarithmic retention time and inversion of the temperature showed that the ureide had four phases, which were identified by polarized microscopic observation to be a solid crystal, two kinds of liquid crystals and an isotropic liquid. The most effective separation of the racemates were achieved when the ureide was in a liquid crystal phase. The thermodynamic parameters were also calculated for these phases. These results might indicate that not only the stereoselectivity, but also the orientation of the optically active moieties in the stationary phase play an important role for the separation of amino acid enantiomers.View full abstractDownload PDF (596K) -
Seishu KOH, Yukari GORIKI, Mitsuyoshi OKAMOTO, Satoshi KAWAI1981 Volume 30 Issue 7 Pages 482-485
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA method for high-performance liquid chromatographic (HPLC) determination of the m- and p-O-methylated products of 3, 4-dihydroxybenzoic acid (DHBA) was investigated and applied to the assay of catechol-O-methyltransferase (COMT) of rat liver. The standard incubation mixture consisted of 0.5 ml of DHBA (600 μg/ml), 0.25 ml of S-adenosyl-L-methionine (4 mM), 0.05 ml of MgCl2 (0.1 M) and 0.2 ml of COMT (10 mg of protein/ml) in 0.05 M phosphate buffer solution (pH 7.2). After incubation at 37°C for 30 min, the reaction was stopped by adding 0.1 ml of 1 N HCl. The mixture was saturated with NaCl, and the products were extracted with 2.0 ml of ethyl acetate containing 4-hydroxybenzoic acid as internal standard. The extract was evaporated to dryness and the residue was redissolved in 1 ml of 1 % acetic acid, and 50 μl of it was applied onto HPLC with a column (15 cm×4 mm I.D., stainless steel) packed with LiChrosorb 5 RP 18 and a mobile phase consisting of acetic acid/acetonitrile/water (1 : 5 : 94 v/v). Detection wavelength was 254 nm.View full abstractDownload PDF (624K) -
Takashi HIRATA, Yosuke OHKURA1981 Volume 30 Issue 7 Pages 485-487
Published: July 05, 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA sensitive and selective photometric method for the determination of phenylpyruvic acid in urine is described, based on the color reaction of the acid with diazotized p-chloroaniline in an alkaline medium. Phenylpyruvic acid in 0.1 ml of urine is extracted with ether at pH less than 1. The extract, after evaporating the solvent, is treated with diazotized p-chloroaniline in the presence of sodium hydroxide, sodium sulfite and sodium hypophosphite at 37°C for 30 min. The resulting formazan derivative is extracted with cyclohexane, and the absorbance of the extract is measured at 500 nm against the reagent blank. The amount of phenylpyruvic acid is calibrated by the standard addition method. This method permits the determination of the acid as low as 5 μg in 0.1 ml urine with good precision, and should be applicable for the acid in urine from patient with phenylketonuria.View full abstractDownload PDF (361K) -
1981 Volume 30 Issue 7 Pages 488
Published: 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSDownload PDF (89K) -
1981 Volume 30 Issue 7 Pages 488a
Published: 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSDownload PDF (89K) -
1981 Volume 30 Issue 7 Pages 488b
Published: 1981
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSDownload PDF (89K)
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