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Volume 40, Issue 6
Displaying 1-13 of 13 articles from this issue
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Satori UTSUMI, Shigeo MATSUNO, Akinori ISOZAKI1991 Volume 40 Issue 6 Pages 257-262
Published: June 05, 1991
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSDiethyldithiocarbamate (DDTC) reacts with silver ion to form a stable chelate. The present paper deals with a method for the indirect determination of chloride ion based on the measurement of Ag-DDTC chelate extracted into carbon tetrachloride. The procedure is as follows: a 10ml aliquot of a sample solution containing less than 5×10-4M (17.8ppm) chloride ion is placed in a glass tube with a stopper. One milliliter of 10% (w/v) citric acid solution and 1ml of 5×10-3M silver nitrate are added, and mixed. After standing for 10min, the resulting AgCl-precipitate is filtered with suction through a 0.45μm membrane filter. A 10ml portion of the filtrate is transferred into a separatory funnel. One milliliter of 2M aqueous ammonia, 1ml of 0.2% (w/v) DDTC·Na solution and 10ml of carbon tetrachloride are added. The mixture is then shaken for 2min. After the phase sparation, the absorbance of the organic phase is measured at 340nm with a 1cm quartz cell using water as a blank. If some interfering ions exist in the sample solution, the resulting AgCl-precipitate collected on the membrane filter can be used for the determination of chloride ion. The precipitate is washed with water and dissolved completely in aqueous ammonia. The subsequent procedure is similar to that for the filtrate as described above. When chloride content is less than 1×10-4M (3.8 ppm), the absorbance measurment of AgCl-precipitate is performed at 280nm on an absorption maximum. The relative standard deviation obtained by the filtrate method for the determination of 5.3 ppm chloride ion in a river water sample was 0.83% (n=10).View full abstractDownload PDF (815K) -
Minoru HOSOYA, Mikio ISHIKURO1991 Volume 40 Issue 6 Pages 263-269
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA new analytical technique of micro amounts of As in high purity iron was developed. Arsenic was separated by coprecipitation with beryllium hydroxide as a BeNH4AsO4 from iron. Arsenic in the precipitate was digested using hydrochloric acid and reduced to AsH3 with dropwise addition of 5ml of 25g/l NaBH4 solution. This reduction technique was simple and rapid (1012 min) as compared with reduction with metallic zinc, because pre-reduction of As(V) to As(III), temperature control of the sample solution for hydride generation and long reduction time (1h) were unnecessary. On the Ag-DDTC spectrophotometry, AsH3 was absorbed into a pyridine or brucine-chloroform solution containing Ag-DDTC, but those solvents had a disagreeable odour or toxicity respectively. In this technique, AsH3 was absorbed into KMnO4 solution containing ammonium molybdate and small amounts of polyvinyl alcohol and then determined by reduced molybdoarsenate spectrophotometry. By this method, the absorption solution is harmless as compared with the Ag-DDTC method. Moreover, a molar absorptivity for the reduced molybdoarsenate spectrophotometry (ε=27000) is larger than it forAg-DDTC method (ε=15000). Therefore, this technique was more practical and could be conveniently applied to the determination of micro amounts of As. The relative standard deviation of this method was approximately 13% for the determinations (n=9, x=0.96μg/g) of 1.0μg/g As in a synthetic sample and the detection limit was 0.3μg/g as for a 1.0g of sample.View full abstractDownload PDF (1101K) -
Hitoshi YAMAGUCHI, Hiroki HARAGUCHI, Haruno OKOCHI1991 Volume 40 Issue 6 Pages 271-276
Published: June 05, 1991
Released on J-STAGE: January 19, 2010
JOURNAL FREE ACCESSAluminium and calcium in silicon carbide powder samples were determined by ICP-AES. The analytical procedure was as follows; fuse 0.5g of silicon carbide with 2.5g of sodium carbonate in a platinum crucible at 1000°C for 30min. Dissolve the melt with water and make the solution acidic with hydrochloric acid. Add perchloric acid and heat the solution until fuming. After cooling, separate the precipitate of silicondioxide by filtration, dilute it to 200ml. Pass the solution through a cation exchange column (AG 50W-X4, 100-200 mesh; 13ml) and wash the column with 200ml of 0.2M nitric acid. Dilute the analytes with 90ml of 2M nitric acid. Dilute the eluate to 100ml and determine Al and Ca by ICP-AES. The matrix element (sodium) was removed by cation exchange chromatography. Quantitative recoveries were obtained for Al and Ca. The analytical concentration range covered was from ppm to % levels.View full abstractDownload PDF (824K) -
Eiji SAITOH, Hajime TOKUDA, Kiyoshi MATSUMOTO1991 Volume 40 Issue 6 Pages 277-282
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA simple automated method has been developed for the analysis of a variety of solvents. The analysis system is based on fused silica capillary gas chromatography and retention indices. Of the eight kinds of capillary columns examined, the DB-1701 crosslinked fused silica capillary column gave us the best resolution and peak shapes in a chromatogram of a typical mixture of solvents. By using the column, it was possible to attain the complete separation of sixty compounds used as solvents, including alcohols, glycols, etc. Retention indices were utilized for the identification of the eluates, for the calculation of which several alcohols, glycols and carbitols were used as reference compounds to improve the long-term reproducibility of the retention indices of the solvents with hydroxy groups; and to simplify the analytical procedures. A series of the processes involved in the proposed method, such as the calculation of the retention indices and a library search and so on, were fully automated by a GC system combined with a personal computer.View full abstractDownload PDF (786K) -
Kenji KATO, Kunitaka SATO1991 Volume 40 Issue 6 Pages 283-288
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA photoacoustic system suitable for pulsed laser excitation was presented for detecting the trace gaseous components in air and high purity gases. The photoacoustic cell used was a longitudinal resonant cell which had a double tube structure. This cell was used as a flow cell. It had a low background. Pulsed Nd: YAG laser (532nm) was used as an exciting source. Nitrogen dioxide diluted with nitrogen was used as sample gas. The inner resonant tubes of 21, 31 and 42cm lengths were tested and it was found that the inner tube of 42cm length was the best because of the low background and good linearity. The signal intensity for nitrogen dioxide was affected by the pulse repetition rate and the sample flow rate. The detection limit for nitrogen dioxide was 5 ppb (S/N=2) under the conditions that sample flow rate was 21/min and pulse repetition rate was 1 pulse per second. It was demonstrated that this system can monitor nitrogen dioxide in room air at every 65s. Further, near infrared (1600-1770nm) photoacoustic spectra of benzen was measured with the use of a pulsed near infrared tunable laser as another exciting source.View full abstractDownload PDF (925K) -
Shoji SAITO, Takeshi MIKI, Hiroshi ITO, Minoru KAMODA, Mituo ITO1991 Volume 40 Issue 6 Pages 289-294
Published: June 05, 1991
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA determining method for Na+, K+ and NH4+ in various foods by ion chromatography (I.C.) was examined. The relationship between retention time of three components and concentration of various acids used as an eluent was tested. From the results, operating conditions of I.C. were decided as follows: column, HITACHI 2720-SK-IC as main-column and 2650L-IC as precolumn; eluent, 3.0mM HCl; flow rate of eluent, 1.0ml/min; detector sensitivity; 30μS/cm and 100μS/cm full scale; oven temp.; 40°C; injection volume; 2.0μl. The following two pretreatments of samples prior to I.C. were tested. (1) Sample was dissolved with water and then filtered. (2) The above filtrate was passed through strong base type anion exchange resin. The observed contents of three components in various foods were statistically analyzed. From the results, the pretreatment procedure (2) was found to be better.View full abstractDownload PDF (886K) -
Tohru HANASAKI, Haruki OHNISHI, Tutomu KUSAOKA, Kenji KUBO1991 Volume 40 Issue 6 Pages 295-300
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe tannic acid turbidimetric method for the determination of cationic polyelectrolyte in wastewater developed by Attia et al. {Br. Poly. J., 7, 135 (1975)} can be applied acrylamide/acrylic acid copolymer by increasing the amounts of the reagents forming turbidity. Procedure: add 15ml of 0.1% tannic acid soln., 20ml of 2M sodium chloride soln. and 1ml of 0.1% EDTA soln. to 10ml of sample water in a 50ml measuring flask. Allow it to stand for an hour at 20°C. Measure the turbidity at 554nm using 2cm cell against a blank. The calibration curves were linear over the concentration range from 0 to 20mg/l for a copolymer (acrylamide/acrylic acid =80/20), from 0 to 30mg/l for a copolymer (acrylamide/acrylic acid=70/30), from 0 to 20mg/l for a copolymer (acrylamide/acrylic acid=60/40) and from 0 to 20mg/l for sodium polyacrylate. The detection limits were 0.85, 2.0, 1.3 and 2.9mg/l for the above mentioned copolymers, respectively. Turbidity was dependent on the temperature and time. The determination method developed here can be explained by Schulze-Hardy's law. However, the mechanism of the determination method for anionic polyelectrolyte may be differed from that for the cationic one.View full abstractDownload PDF (714K) -
Yasuo NAKABAYASHI, Kenji NAGAOKA, Yoshitaka MASUDA, Ryu SHINKE1991 Volume 40 Issue 6 Pages 301-304
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSSimultaneous determination of manganese and zinc in wastewater by capillary isotachophoresis using solvent extraction as a concentration procedure has been carried out. The sample was decomposed with concentrated nitric acid and 9M sulfuric acid, and metal ions were extracted as diethyldithiocarbamate complexes into butyl acetate, and then the reverse extraction was done with EDTA solution. An aqueous solution of theconcentrate (40times) was injected in isotachophoretic analyzer equipped with potential gradient detector. The leading electrolyte was composed of 5mM HCl and 3mM β-alanine in 45%v/v acetone-water solvent, and the terminating electrolyte was 5mM EDTA·2Na aqueous solution. Only manganese and zinc were quantitatively determined in the range of 0.05 to 2.0mg l-1 for manganese and 0.06 to 2.0mg l-1 for zinc, the injection volume being kept constant at 10μl. The correlation between the proposed method and the conventional one (the spectrophotometric method) was satisfactory.View full abstractDownload PDF (470K) -
Tadao SAKAI, Noriko OHNO, Hideto SASAKI1991 Volume 40 Issue 6 Pages 305-308
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA sensitive spectrophotometric determination of vitamin B12 (V. B12) in complexing vitamin preparations is proposed. Since V. B12 contained cobalt, it is possible to use cobalt for the V. B12 assay. Cobalt reacts with 3-(2-pyridy1)-5, 6-dipheny1-1, 2, 4-triazine (PDT) to form a cationic chelate ion and the complex can be extracted into 1, 2-dichloroethane with tetrabromophenolphthalein ethyl ester (TBPE) at pH 9.0. The composition of the ternary complex is assumed to be Co(PDT)3(TBPE)2. A predetermined amount of V. B12 (0.1-3mg) was heated at 200°C for 2h with 20ml of nitric acid. After adding 10ml of nitric acid and 2ml of perchloric acid, the mixture was evaporated to dryness. The residue was dissolved in 30ml of 1M hydrochloric acid by heating and diluted to 50ml with distilled water. The required volume of the sample solution containing 0.5-2.5μg cobalt (10-60μg V. B12) was transferred to a 50-ml volumetric flask. To this, 1ml of 10-4 M potassium periodate, 2% Tiron, 7.5×10-3M PDT, 10ml of the borate-phosphate buffer (pH 9), and 1ml of 1.35×10-3M TBPE, were added. It was then diluted to 50ml with distilled water. The mixture was transferred to a separatory funnel and shaken for 5 min with 10 ml of 1, 2-dichloroethane. The organic phase was centrifuged and the absorbance was measured at 610 nm against a reagent blank. Molar absorptivity was 134000mol-1 cm -1 l, and relative standard deviation, 1.7% for ten determinations of 30 ng ml-1 cobalt. Fe(II) was tolerated up to 0.1μg ml-1 (5-fold for cobalt) by addition of 2×10-6 M potassium periodate and 0.04% Tiron and also Cu(II), 0.1μg ml-1 by adding 0.2M thiourea. This method can be applied to the indirect assay of V. B12 compounds such as cianocobalamin, hydroxocobalamin and mecobalamin in commercial preparations containing other vitamins.View full abstractDownload PDF (623K) -
Yusuke KUNO, Katsuya KAWABE, Takao AKIYAMA1991 Volume 40 Issue 6 Pages T113-T118
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSAn automatic system for the determination of the stable oxidation states of uranium and plutonium, and nitric acid in nuclear fuel reprocessing streams has been developed. The system based on a spectrophotometry is capable of rapidly determining U(IV), U(VI), Pu(III), Pu(IV) and Pu(VI). The spectrum obtained from a mixed solution is separated into individual spectra of several components with graphical operations. Acidic concentration can also be obtained from the ratio of specific peaks in a spectrum of U(IV), U(VI), Pu(III) or Pu(IV).View full abstractDownload PDF (802K) -
Hideji SATOH, Yoichi KIKUCHI, Keiichi SATOH, Toshio SUZUKI, Kiyoshi SA ...1991 Volume 40 Issue 6 Pages T119-T123
Published: June 05, 1991
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA highly sensitive spectrophotometer system was applied to a solvent extraction/spectrophotometry by employing a phase separator with a porous polytetrafluoroethylene membrane. The organic phase, which was separated using the phase separator from the aqueous phase, was pumped to a flowthrough cell, and recycled into the extraction vessel. By successive addition of titrant reagent to the extraction vessel, data under various experimental conditions such as standard addition and pH dependence were collected from one sample solution. This flow recycle system significantly minimizes the experimental errors caused by the preparation of sample solutions and makes effective use of the spectrophotometric measurements of organic phase up to 0.0002 absorbance. The performance of the system was examined by the extraction of metal-8-quinolinol complexes and it was applied to a simultaneous determination of iron(III), copper(II) and aluminium(III). Detection limits of sub-ppb were attained.View full abstractDownload PDF (814K) -
Yasushi NAKAMURA, Yukio MURAI, Dezhen NI, Yongming LIU1991 Volume 40 Issue 6 Pages T125-T130
Published: June 05, 1991
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA method for the determination of rare earth impurities in terbium and terbium oxide by inductively coupled plasma atomic emission spectrometry interfaced with high performance liquid chromatography (HPLC/ICP-AES) has been studied. The rare earth impurities were separated from terbium for 10min using a silica-octadecyl column with a eluent of 2-hydroxyisobutyric acid aqueous solution by a concentration gradient method. Not only the mutual separation of the impurities were satisfactory, but the rapid elution gave sharp peaks and sensitive detection. Up to 30μl of a 1g/100ml solution of terbium was able to be injected into the column. By decreasing the radio frequency power in ICP-AES to 0.8kW, the signal-to-background ratio was increased more than 5times that with the usual power, 1.3kW. In the proposed method, the recoveries of rare earthimpurities in terbium oxide were 85-100%. An expensive terbium oxide was not required as a matrix matching standard in this procedure.View full abstractDownload PDF (729K) -
Kenji YAMAGUCHI, Sueo NISHI1991 Volume 40 Issue 6 Pages T131-T136
Published: June 05, 1991
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSCapillary GC/MS combined with purge and trap technique has been applied to analysis for traces of dichloroethyleneisomers (DCEs) in water. With the cryo-capillary interface mode, the detection limit was 0.01μg/l with 5ml sample size. Reproducibility ofselected ion monitoring (SIM) chromatographic peak areas were in the range of 4-7%for concentration of 1μg/l, but were 10% for 0.05μg/l concentrations. The SIM peakintensity ratios between monitor ions showed excellent reproducibilities. The resultsobtained with the cryo-column mode were also discussed and compared with those of the cryo-capillary interface mode.View full abstractDownload PDF (750K)
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