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Volume 35, Issue 11
Displaying 1-12 of 12 articles from this issue
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Koichi SAITOH1986 Volume 35 Issue 11 Pages 895-910
Published: November 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSStudies on liquid chromatography (LC) of metal complexes by our group are critically reviewed. In the third chapter is described gel permeation chromatography (GPC) of metal complexes of, β-diketones. The distribution coefficient, Kav, for every metal complex depended much on the solvent used. Practical GPC was regarded as one based on a combined function of size exclusion effect and partition effect. Introducing the concept of a regular solution to a phase system of GPC, the contribution of the partition effect could be estimated from the solubility parameters of solute, solvent and gel, the degree of gel swelling, and molar volume of the solute. Solubility parameter was the most useful guide for choice of the solvent to be used. In the fourth chapter, the HPTLC or HPLC behavior of porphyrin metal complexes is described. The effects of stationary phase material and mobile phase solvent on the retention of various porphyrins and porphyrin metal complexes were investigated. The effects of the ligated metal ion of complex and the chemical structure of ligating porphyrin were also studied. Reversed phase HPLC and HPTLC were successfully used for separation of several porphyrin metal complexes. In the fifth chapter was introduced the application of LC to analysis of petroleum samples, especially with respect to the vanadium- or nickel-containing species in the samples. By use of both GPC and HPLC equipped with rapid-scanning UV-visible spectrophotometric detector and AAS, several vanadium species as porphyrin complexes were separated and detected.View full abstractDownload PDF (2518K) -
Hiroshi HASHITANI, Hideyo YOSHIDA, Takeo ADACHI, Kimie IZAWA1986 Volume 35 Issue 11 Pages 911-915
Published: November 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA wet oxidation decomposition method of graphite has been developed to determine metal impurities accurately. One gram of graphite powder can be decomposed in 3h with 0.5g of periodic acid (H5IO6) in 20ml of perchloric acid when heated at 200°C in a fused silica flask with a reflux condenser. After decomposition, iodine compounds are removed as iodine by adding hydrogen peroxide. By the proposed decomposition method, four graphite reference materials were analysed for aluminium, iron, nickel, titanium, vanadium and calcium. Since graphite is porous material, impurity elements arc expected to be leached out with hot mineral acid. One gram of graphite powder was heated for 3 h with hydrochloric acid-nitric acid (1:1). About 95% of each impurity element was recovered, in comparison with the value obtained by the wet decomposition. Good agreement of the analytical results for those elements between the methods supports the former view that the elements exists between parallel sheets of carbon atoms and/or grain boundaries. Spex G-standards for emission spectrography was analyzed for nine elements.View full abstractDownload PDF (836K) -
Hiroshi HASHITANI, Kimie IZAWA, Hideyo YOSHIDA, Takeo ADACHI1986 Volume 35 Issue 11 Pages 916-919
Published: November 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIn order to determine traces of sulfur in graphite accurately, a wet oxidation decomposition method has been developed. Sulfur is finally determined spectrophotometrically as Ethylene Blue. Graphite is decomposed through oxidation with periodate in fuming perchloric acid. One gram of graphite powder was completely decomposed in 3 h. The established method includes: decomposition of graphite (less than 2g) in 20ml of perchloric acid containing 0.5g of iodine at 200°C; recovery of iodine with hydrogen peroxide; evaporation of excess perchloric acid; reduction of sulfate with a reductant; distillation of sulfur as sulfide, color development with N, N-diethyl-p-phenylenediamine (DEPD) in presence of iron (III); and measurement of the absorbance of the colored solution at 670 nm. Stability of the standard sulfur solution, effect of pH on the color development, and amounts of DEPD and iron (III) were examined. By the established method, 23 block samples taken from 11 brand graphite materials were analysed. Refined graphite contained less than 10ppm of sulfur, and unpurified graphite 3 to 90 ppm, depending on the raw materials. The segregation of sulfur in a graphite block was generally not so much, compared with that of metal impurities. It was also found that about 90% of sulfur in graphite was leached into fuming perchloric acid, in comparison with the wet oxidation decomposition method.View full abstractDownload PDF (710K) -
Hiroshi HASHITANI, Hideyo YOSHIDA, Kimie IZAWA, Takeo ADACHI1986 Volume 35 Issue 11 Pages 920-925
Published: November 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSEleven brands of graphite materials for nuclear reactors from four countries (100 to 3300kg) were precisely analyzed to identify their impurities. The powder samples for analysis (ca. 100g each) were prepared by shaving 23 block samples (ca. 1kg each) with a tungsten carbide bite and mixing well. Twelve elements (Al, Ca, Cd, Co, Cu, Fe, Li, Mg, Mn, Ti, V) were determined from solutions obtained by a newly developed wet oxidation decomposition method for graphite. The results obtained are summarized as follows: (1) Major impurity elements are iron, calcium and silicon. Titanium is next to the three elements, and aluminium and vanadium are comparable to titanium in some graphite materials. (2) Unrefined graphite materials contained 400 to 2400ppm of ash.The content of ash (sum of unvolatile elements expressed as oxides) is higher in inner part of the graphite materials than in the outer. Heterogeneity of sulfur is not so much compared with the metal impurities. (3) One gram-sample obtained directly from the block sample by drilling, shows very dispersed analytical values which reveals the existence of colonies of the impurities. (4) Corrosion rate of graphite (with 0.65% water at 1000°C for 10h), increases with increasing iron content but not with the ash content.View full abstractDownload PDF (912K) -
Akio SAKURAGAWA1986 Volume 35 Issue 11 Pages 926-930
Published: November 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe reaction between slightly hydrolyzed zirconium(IV) and Xylenol Orange (XO) is catalyzed by the presence of micro amounts of fluoride, sulfate and phosphate ions. This catalytic reaction was applied to the spectrophotometric determination of a micro amount of phosphate ion. Addition of cetyltrimethylammonium chloride(CTAC) to the zirconium(IV)-XO complex resulted in a bathochromic shift as well as a remarkable increase in absorbance. With the aid of CTAC, the sensitivity of the method was much improved. Recommended procedure is as follows: A 10cm3 aliquot of sample solution containing less than 0.3μg/cm3 of phosphate ion and 1.0cm3 of 2×10-4mol dm-3 XO solution were placed in a test tube with a stopper, followed by addition of 1.0cm3 3×10-3mol dm-3 CTAC solution (in 3.00mol dm-3 HCl). Then, 1.0cm3 of 2×10-4mol dm-3 slightly hydrolyzed zirconium(IV) solution (in 0.02mol dm-3 HCl) was added to the above sample solution and the test tube placed in a water bath at 25°C. Fourty min after the addition of the zirconium (IV) solution, the absorbance was measured at 605nm against water as a reference. Using this method, phosphate ion ranging 0.01μg/cm3 to 0.30μg/cm3 can be determined. Fluoride ion gave rise to interference in this method, but could be removed in advance by distillation with hexamethyldisilazane. Sulfate ion also showed interference, nevertheless, phosphate ion in water samples could be determined by this method after separating it from other matrices present in the samples using an activated carbon impregnated zirconium(IV). The relative standard deviation for 0.1μg/cm3 phosphate ion (n= 5) was 3.7%. The proposed method was applied to tap water and well water samples. The values agreed well with those obtained by the spectrophotometry with Molybdenum Blue. The recoveries tested by standard addition were within 101102%.View full abstractDownload PDF (666K) -
Koji MATSUSAKI, Takashi YOSHINO1986 Volume 35 Issue 11 Pages 931-934
Published: November 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSMethod for removal of the chloride interference in the determination of thallium by AAS with a graphite furnace has been investigated. The chloride interference arises from formation of thallium (I) chloride in the sample solution; this has been confirmed by examine the effects of coexisting chloride concentration and pH of sample solution on the atomic absorption signal of thallium. The ammonium salt of EDTA is very suitable as an additive to remove the chloride interference, since chloride formation of thallium and other cations can be masked by EDTA. Furthermore, the use of this salt yields readily volatile ammonium chloride which can be easily removed from the furnace in drying and ashing steps. In the presence of 0.02M EDTA at pH 10 with ammonia the maximum allowable concentration of coexisting metallic chloride is about 400times larger than in 0.1M nitric acid and 40times than in 0.05M sulfuric acid.View full abstractDownload PDF (655K) -
Tohru TANAKA, Satoru KUROSAWA, Nakahachiro HONMA1986 Volume 35 Issue 11 Pages 935-940
Published: November 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA systematic separation procedure has been established for the determination of impurities in gallium arsenide using anion exchange and ether extraction. This was previously thought difficult in practical analyses since the impurity amounts were 106 times smaller than the amounts of the gallium and arsenic matrices. The separation of aluminium, boron, chromium and manganese from the matrices was achieved by using 6M hydrochloric acid in a 25-cm-length column, which also increased the arsenic elution delay from the elution of the above four elements. These impurities were recovered up to 100% and arsenic was quantitatively removed by collecting 02ml of eluted solution. It was demonstrated that chromium and manganese are separable even in nanogram amounts, equivalent to parts per million by weight (ppm wt) in gallium arsenide, whereas aluminium and boron have not yet been separated due to contamination. In the separation of selenium using a 50-cm-column, recovery was only 80% due to its disproportionation reaction. Copper and gallium, which can only be eluted with dilute hydrochloric acid, were easily separated from arsenic. In the presence of higher gallium concentrations ether extraction was necessary for the successful separation of copper and gallium from arsenic by anoin exchange. Four times extraction successfully led to a 94% copper recovery and almost perfect gallium removal. Having extremely strong adsorbability in the presence of chloride ions, zinc can be eluted quantitatively with 2M nitric acid. Matrix contamination in the zinc solution was found to be negligible by checking at the 10ppm wt level in gallium arsenide.View full abstractDownload PDF (1097K) -
Shigehiko YAMAGUCHI, Jiro HIRANO, Yoshihiro ISODA1986 Volume 35 Issue 11 Pages 941-943
Published: November 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSCompositional determination is studied for terpolymers by pyrolysis GC. Pyrolysis was performed at 590°C using a Curie point pyrolyzer. The correction factors for the compositional analysis of 2-hydroxy ethyl methacrylate(HEMA)-butyl acrylate (BA)-ethyl methacrylate (EMA) terpolymers can be obtained from the HEMA/EMA and BA/EMA ratios in the pyrolytic products using the multiple regression analysis. The correction factor for the analysis of styrene(St)-ethyl acrylate(EA)-EMA terpolymers can be obtained similarly. The composition of the other St-acrylate-methacrylate terpolymers of St-BA-methyl methacrylate (MMA) can be determined exactly by proposed estimation of the correction factors. The proposed method could be generally applicable to the determination of various terpolymer compositions.View full abstractDownload PDF (495K) -
Simultaneous determination of nitrate and nitrite in rainwater by HPLC with electrochemical detectorAkiko ISHIGAMI, Seiko KOYANAKA, Tadayasu TOGAWA, Ichiro KOSHIISHI, Tos ...1986 Volume 35 Issue 11 Pages 944-946
Published: November 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA method for the simultaneous determination of nitrate and nitrite was studied by HPLC with an electrochemical detector (ECD). Nitrate and nitrite were separated by TSK gel QAE-2SW (150mm×4mm i.d.) and nitrate was reduced to nitrite on a copper-cadmium column (100mm×5mm i.d.). Nitrite was detected by ECD with a glassy carbon electrode as a working electrode, the potential of which was set at+0.9V vs. Ag/AgCl. The mobile phase consisting of 0.1M phosphate buffer containing 0.05M sodium chloride (pH 7.0) was pumped at a flow rate of 0.5ml/min.Injection volume was 20μl. According to this method, the retention times of nitrate and nitrite were 8.0 and 9.8min, respectively. Calibration curves for both anions were linear in the range of 0.240ng as N and relative standard deviation (n=5) were less than 2%. We applied this method to the determination of nitrate and nitrite in rainwater.View full abstractDownload PDF (521K) -
Atsushi CHIBA, Shoko SUYAMA, Tadahiko OGAWA1986 Volume 35 Issue 11 Pages 946-948
Published: November 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe separation was carried out at 90°C. The developing solution used was 0.05, 3M hydrochloric acid and 0.28% ammonia water. Initially, formation of metal complex was tried as a means to separate the metal ions. Filter papers impregnated with 1% dimethylglyoxime, 1% 8-quinolinol, saturated rebeanic acid, 0.1% p-dimethylaminobenzylidenrhodanine, 0.05% benzidine, 0.2% bismuthiol II, 0.1% p-nitrosodimethylaniline, 0.1% 1-(2-pyridilazo)-2-napthol, 1% sodium diethyldithiocarbonate and 0.1 % ascorbic acid solution were used. Metal ions were separated by combining these papers and the developing solutions. Metal ions were separated into two groups, further separation into individual metal ions was not possible. Individual metal ion separation was achieved based on the solubilities of metal sulfides and the formation of a metal complex. Six metal ions, Au(III), Ir(IV), Pd(II), Pt(IV), Rh (III) and Ru(III), were separated. The time necessary for the separation was about 1h. The metal ions were detected from the colors of either their sulfide or metal complex. Separable ranges were Au(III); 0.251.0μg, Ir(IV);0.21.5μg, Pd(II); 0.31.8μg, Pt(IV); 0.62.2μg, Rh(III); 0.451.2μg and Ru (III); 0.30.7 μg. The lower value for each element (ion) shows the detection limit.View full abstractDownload PDF (549K) -
Kazuo ISE1986 Volume 35 Issue 11 Pages T107-T110
Published: November 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSRhenium occurs as a commercial by-product in the dust residue of flues during the roasting of molybdenite, in which the rhenium is associated with a large amount of molybdenum. Rhenium contained in the dust was analyzed by means of flame photometry, which is about ten times more sensitive than AAS. Determination of rhenium is significantly interfered by the coexistence of molybdenum in the system; the positive error amounts to 8% when the amount of molybdenum is ten times as large as that of rhenium and to 90% when the amount is 100times as much. To avoid this difficulty, it was attempted to extract rhenium with a 1w/v% solution of tetrabutylammonium chloride in dichloromethane to remove molybdenum and other interfering elements. The detectable limit was 0.4ppm, and the repetition accuracy was within 2%, respectively.View full abstractDownload PDF (575K) -
Koji ISHIDA, Masahiro MATSUZUKA, Tomoshige MORITA, Takeshi HAMADA1986 Volume 35 Issue 11 Pages T111-T114
Published: November 05, 1986
Released on J-STAGE: May 07, 2010
JOURNAL FREE ACCESSThe method for the spectrophotometric determination of Ir(III, IV) with Leuco-Crystal Violet(LCV) was improved both in simplicity and in precision, allowing wider application in practical use. Samples are treated with HCl and HNO3 in the presence of NaCl, allowed to react with LCV purified by recrystallization and silica gel chromatography, and finally subjected to color development in acetate buffer solution containing hydroxylamine. Beer's law holds over the concentration range, 350μgIr/10ml solution. Fifteen runs with 1.87μgIr/ml solution gave an average absorbance of 0.501, with a relative standard deviation of 0.45%.View full abstractDownload PDF (763K)
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