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Junichi KONDO, Toshi IMAOKA, Nobuyuki SUZUKI, Takao KAWASAKI, Akio NAK ...
1994 Volume 10 Issue 5 Pages
697-703
Published: October 10, 1994
Released on J-STAGE: July 04, 2006
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N-[4-(6-Methoxy-2-benzoxazolyl)]benzoyl-L-phenylalanine (BOX-L-Phe) and
N-[4-(6-methoxy-2-benzoxazolyl)]benzoyl-L-proline (BOX-L-Pro) have been synthesized to permit separation of amine enantiomers by high-performance liquid chromatography. Enantiomeric amines were readily condensed with the chiral derivatization reagents in the presence of 2, 2′-dipyridyl disulfide and triphenylphosphine. The diastereomeric BOX-L-Pro amides were separable by both normal-phase and reversed-phase chromatography. They could be sensitively detected fluorometrically at 432nm, with excitation at 325nm in the reversed-phase mode. The detection limit of the BOX-L-Pro derivative ofR-1-(1-naphthyl)ethylamine was 30fmol at a signal-to-noise ratio of 3.
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Keiji GAMOH, Kamal A. KETULY, W. John COLE, Charles J. W. BROOKS, Robe ...
1994 Volume 10 Issue 5 Pages
705-711
Published: October 10, 1994
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Cyclic 2-(
N, N-dimethylaminomethyl)ferroceneboronate (DMAM-FcB) esters of a variety of 1, 2-diols have been examined by gas and liquid chromatography as well as by mass spectrometry. Some comparisons have been made with analogous ferroceneboronate (FcB) esters. Under the conditions used for reversed-phase high-performance liquid chromatography, more of the FcB than of the DMAM-FcB esters were stable. Many of the derivatives were suitable for gas chromatography; the retention index increments for the dimethylaminomethyl substituent were on the order of 200 units on a methylsilicone phase. A satisfactory separation of diastereomeric boronates derived from chiral diols could be performed in the same achiral stationary phase. In most instances, the mass spectra of DMAM-FcB esters showed clear molecular ions along with prominent ions of
m/z (M-44), resulting from a loss of the (CH
3)
2N radical. Evidence for the formation of mono- and bis-boronates of ecdysterone was obtained by fast atom bombardment mass spectrometry.
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Yasuaki TAKAD, Kanae NAKAYAMA, Motoko YOSHIDA, Minoru SAKAIRI
1994 Volume 10 Issue 5 Pages
713-717
Published: October 10, 1994
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Tryptic digests of horse-heart cytochrome c have been analyzed using capillary electrophoresis/mass spectrometry. Analytical conditions for capillary electrophoresis/mass spectrometry of peptides, the pH of capillary electrophoresis buffers and aminoethylaminopropyl-silylation of fused-silica capillaries, have been investigated to improve the reproducibility in migration times and the efficiency of electrospray ionization. A combination of 1% formic acid as electrophoresis solution and a chemically modified capillary has been found to be the best of optimal for capillary electrophoresis/mass spectrometry of peptides.
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Masanori HORI, Yuko SAHASHI, Seiji KOIKE, Ryohei YAMAOKA, Masanori SAT ...
1994 Volume 10 Issue 5 Pages
719-724
Published: October 10, 1994
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A molecular species analysis of polyunsaturated fatty acid-enriched fish oil, a complex and labile mixture of various triacylglycerols, was carried out by high-performance liquid chromatography/fast atom bombardment mass spectrometry (HPLC/FAB-MS)•with a frit-FAB interface. Positive and negative ion FAB mass spectra and mass chromatograms provided indications of the possible combination of fatty acids in each triacylglycerol component. The actual triacylglycerol retention time values obtained by mass spectrometry were compared with those predicted by the relative retention potential index theory. The two values coincided well with each other. This method thus facilitates the identification of components overlapping in HPLC without fractionation.
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Yuzuru HAYASH, Rieko MATSUDA
1994 Volume 10 Issue 5 Pages
725-730
Published: October 10, 1994
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Recently, a probability theory to predict the precision or relative standard deviation (RSD) of measurements in analytical instruments has been proposed. The aim of this paper is to examine the precision of data obtained by a high-performance liquid chromatograph (HPLC) equipped with photodiode detector and photomultiplier on the basis of the above-mentioned theory. The baseline drift, which is often formulated as 1/
f noise, is approximated by the mixed random process of white noise and Markov process. Of six parameters necessary for the uncertainty prediction, three parameters are determined from the power spectral density of the baseline drift: the standard deviations (SD),
w, of the white noise and the SD, m, and retention parameter, ρ, of the Markov process. The others are signal domain,
kf, signal area,
A, over domain,
kf, and independent error,
I (mainly from the injection error). No arbitrary constants are involved. The prediction is shown to be superb for peaks with various areas, heights and widths over a wide concentration range in the HPLC analysis for some aromatic compounds. The applicability of the uncertainty prediction in analytical chemistry is discussed.
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Kunishige NAIT, Tadahiro OKABE, Sadaaki MORIGUCHI, Shinsuke TAKEI
1994 Volume 10 Issue 5 Pages
731-736
Published: October 10, 1994
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A mixed retention mechanism was studied in gas-liquid chromatography of some hydrocarbons and dialkyl ethers using packed columns of silica gel beads coated with different amounts of tricresyl phosphate (TCP). Two adsorption equilibria, on solid surface of silica gel and on organic surface of a monolayer of TCP dominantly contribute to solute retention until the silica gel surface is completely covered with a monolayer of TCP. For hydrocarbons, adsorption on solid surface of silica gel is promoted by formation of a weak 1:1 solute-TCP adduct through lateral interaction between adsorbed solute and TCP molecules. An excess of TCP over an amount necessary for formation of the monolayer on the whole of silica gel surface forms a bulk liquid on the deactivated surface of silica gel, so that bulk solution partition concurrently contributes to solute retention, together with adsorption on the TCP monolayer. Distribution constants of these sorption equilibria could be calculated as reasonable values for any solute.
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Akiko HIROSE, Hiroshi YAMASHITA, Takashi MAEKAWA
1994 Volume 10 Issue 5 Pages
737-741
Published: October 10, 1994
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Dispersed porous spherical silica particles were prepared by a sol-gel process from solutions of tetramethoxysilane (TMOS), polyethyleneglycol (PEG), H
2O and organic solvent in W/O (water in oil phase) emulsions. The interconnected pores can be made by eliminating PEG from gel bodies. Such PEG originates by phase separation between the PEG and the polymerizing silica in common solvents. Microstructures of the particles are affected by the compositions of the starting solutions. The pore diameter increases with an increase in molecular weight of PEG when the molar ratio of PEG as monomer unit to TMOS is fixed to 0.3. The pore diameter decreases and specific surface area increases with an increase in the content of PEG having molecular weight of 50000 when the [PEG]/[TMOS] molar ratio is greater than 0.3. The pore diameter decreases by use of basic solvents such as
N, N-dimethylformamide (DMF) and formamide (FA) instead of methanol.
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Tatsuya SEKINE, Ivana KOBELOVA, Junji NORO, Nguyen THI KIM DUNG
1994 Volume 10 Issue 5 Pages
743-748
Published: October 10, 1994
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The solvent extraction of zinc(II) in 0.1mol dm-3 sodium chloride solutions with 1-naphthoic acid (HA) into chloroform was measured in the absence and presence of tetrabutylammonium ions (tba
+) or trioctylphosphine oxide (TOPO). The extraction of zinc(II) with 1-naphthoic acid was rather poor and the extracted species were in the form of ZnA
2 and ZnA
2(HA)
2 when the metal concentration in the organic phase was lower than 3×10
-5mol dm-3. However, the polymerized species, Zn
nA
2n(HA)
m, were also extracted when zinc(II) concentration in the organic phase was higher than that value. The addition of tba
+ or TOPO enhanced the extraction of zinc(II) 1-naphthoate. This was explained in terms of the extraction of tba
+ZnA
3- or ZnA
2TOPO species. Thus 1-naphthoic acid was found to be an effective extractant for zinc(II) only in the presence of bulky cations or solvating type extractants. We considered the reason why only the monomeric zinc(II) species of the ternary complex or the TOPO adduct was extracted.
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Etty PURNAMAWATY, Tsuyoshi AMIMOTO, Hisanori IMURA, Yoshiharu USUI, Ko ...
1994 Volume 10 Issue 5 Pages
749-753
Published: October 10, 1994
Released on J-STAGE: July 04, 2006
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The extraction equilibria of molybdenum(VI) with several alkylated 8-quinolinol derivatives (HQ): 2-methyl-5-octyloxymethyl-8-quinolinol (HMO
8Q), 5-octyloxymethyl-8-quinolinol (HO
8Q), and 5-(4-nitrophenylazo)-7-(4-ethyl-1-methyloctyl)-8-quinolinol (HNEQ) have been investigated. Molybdenum(VI) was completely extracted with a 0.01M extractant in chloroform from an aqueous phase at 1M (1M=1mol dm-3) HCl-pH 5 for HMO
8Q, 2M HCl-pH 6 for HO
8Q and 4M HCl-pH 5 for HNEQ. The extraction constants, log
Kex(=[MoO
2(Q)
2]
org/[MoO
42-][H
+]
2[HQ]
2org), are 17.72±0.06 (HO
8Q-CHCl
3), 14.90±0.07 (HMO
8Q-CHCl
3), 17.00±0.07 (HNEQ-CCl
4) and 17.18±0.08 (HO
8Q-CCl
4) at 25°C. The molybdenum(VI)-HQ complexes, except the HO
8Q complex in an organic phase could be easily stripped with an aqueous ammonia solution. Molybdenum(VI) was selectively separated with alkylated 8-quinolinol derivatives from many metal ions, such as iron(III), cobalt(II), nickel(II), copper(II), zinc(II) and gallium(III).
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Koichi YAMAMOTO, Miwa ENDO
1994 Volume 10 Issue 5 Pages
755-759
Published: October 10, 1994
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The distribution behavior of ion associates of the tetraiodobismate(III) anion, BiI
4-, with eight quaternary ammonium cations between a chloroform and an aqueous phase was examined, and the extraction constants (log
Kex) were determined. The extractability with long-chain alkyltrimethylammonium cations (group I) is greater than that with symmetrical tetraalkylammonium cations (group II). The contributions of a methylene group in the cations of groups I and II to log
Kex were found to be about 0.54 and about 0.40 on the average, respectively. From the extraction constants obtained, a highly sensitive extraction-spectrophotometric method of bismuth was developed.
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Takashi TOMIYASU, Hayao SAKAMOTO, Norinobu YONEHARA
1994 Volume 10 Issue 5 Pages
761-764
Published: October 10, 1994
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A catalytic photometric method for the determination of trace amounts of iron is proposed. In the presence of iron (Fe
II and Fe
III), chlorpromazine is oxidized by hydrogen peroxide in a hydrochloric acid solution to form a red intermediate, which is further oxidized to a colorless compound. The reaction is followed by measuring an increase in the absorbance at 525nm; the absorbance/time curve increased with the increase in the reaction time, and reaches a maximum value. Since the slope of the linear range of absorbance/time curves increases with the increase in the iron concentration, tan α[=_??_(abs.)/_??_(sec.)] is used as a parameter for the iron determination. Under the optimum experimental conditions (0.011 M chlorpromazine, 0.43M hydrochloric acid, 0.12M hydrogen peroxide, 30°C), iron can be determined in the range 5-200μg l
-1. The relative standard deviations are 0.8, 2.3 and 6.6% for 80, 40 and 10μg l
-1, respectively. Under the reaction conditions, W
VI, S
2O
32-, IO
3-, I
-, NO
2- and BrO
3- showed interference at concentrations of 1mg l
-1. These ions showed no interference at concentrations one order lower. The procedure has been applied to the determination of iron in tap and natural fresh water samples.
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Tomozo KOH, Noriaki TAKAHASHI, Keiko YOKOYAMA
1994 Volume 10 Issue 5 Pages
765-768
Published: October 10, 1994
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For reaction with thiosulfate, excess silver(I) was extracted as an ion-pair of dicyanoargentate(I) with Methylene Blue; the extract was measured spectrophotometrically at 657nm for the determination of thiosulfate. The conditions for thiosulfate to be stoichiometrically converted into silver sulfide were established by varying the pH and reaction time. A linear calibration graph with a negative slope was obtained over the 5.4×10
-8-4.5×10
-6M (0.006-0.504ppm) thiosulfate. The relative standard deviation was 0.79% at the 2.5×10
-6M thiosulfate level. The effective molar desorptivity for thiosulfate at 657nm is -1.99×10
5l mol
-1 cm
-1. The proposed method has been successfully applied to the determination of thiosulfate in hot-spring water containing chloride.
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Hideji TANAKA, Terumi FUKUOKA, Kensaku OKAMOTO
1994 Volume 10 Issue 5 Pages
769-774
Published: October 10, 1994
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Cobalt(III) oxidation was applied to the decomposition of organic phosphorus compounds as a pretreatment of a spectrophotometric determination of organic phosphorus. A cobalt(III) solution (
ca. 0.16mol dm
-3), prepared through the electrolysis of a 0.2mol dm
-3 cobalt(II) sulfate solution containing 5mol dm
-3 sulfuric acid, was mixed with a sample solution containing a phosphorus compound at a volume ratio of 1:5, and allowed to stand for oxidation. After excess cobalt(III) ions had been reduced to cobalt(II) ions with ascorbic acid, the concentration of phosphate ions in the sample solution was determined by Molybdenum Blue spectrophotometry at 880nm. The cobalt(III) ions could completely convert the mg dm
-3 level of phosphorus of organic compounds having a C-O-P or C-P bond into phosphate ions through the treatment within 10min at room temperature, and did not interfere with the subsequent determination. Although phosphonic and phosphinic acids could be oxidized by cobalt(III) ions, condensed phosphates required heating at 95-100°C during the cobalt(III) treatment for complete hydrolysis. Since the present method was free from any interference from coexisting organic and inorganic substances, except at a relatively high level of reducing substances, it is applicable to organic phosphorus determinations in real water samples.
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Junichi SHIDA, Yoshiyasu TSUJIKAWA
1994 Volume 10 Issue 5 Pages
775-777
Published: October 10, 1994
Released on J-STAGE: July 04, 2006
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A preconcentration technique having a high concentration factor, based on collecting trace elements on a membrane filter and dissolving the membrane filter with them in an organic solvent, has been applied to the spectrophotometric determination of titanium(IV) in environmental samples. Titanium reacts with sodium 1, 2-dihydroxybenzene-3, 5-disulfonic acid (Tiron) to form a water-soluble chelate anion, which, in turn, forms a precipitate with benzyldimethyltetradecylammonium chloride (Zephiramine). After the precipitate is filtered through a membrane filter it is dissolved together with the filter into dimethyl sulfoxide (DMSO). The absorbance of the solution is then measured at 382nm. In the presence of vanadium(V) it is performed at 382 and 660nm. Molybdenum(VI) must be previously removed by extraction with α-benzoinoxime. The accuracy and precision of the proposed method have been confirmed by the determination of titanium(IV) in various plant standards. Titanium(IV) in mine drainage was determined at the ng/ml level.
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S. TOKALÌOGLU, S. KARTAL, L. ELCI
1994 Volume 10 Issue 5 Pages
779-782
Published: October 10, 1994
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A column filled with Amberlite XAD-1180 resin was examined in order to test its suitability for extracting inorganic complexes of Cu, Cd, Pb, Bi, Ni, Fe, Mn and Co from sulfuric, nitric or hydrochloric acid solutions containing iodide, thiocyanate or their mixtures. The proposed procedure was applied to the determination of Cu, Cd, Pb and Bi in pure zinc metals by flame- or graphite furnace-atomic absorption spectrometry with good results, such as recoveries _??_95%, relative standard deviations _??_6% (n=10) and detection limits _??_0.200μg cm
-3.
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Kazunori SHINOTSUKA, Mitsuru EBIHAR
1994 Volume 10 Issue 5 Pages
783-787
Published: October 10, 1994
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For the determination of trace K in geological and cosmochemical samples, a simple and effective procedure of radiochemical neutron activation analysis is presented. Although this procedure is essentially based on a previous report by Ebihara, it has been extensively revised in order to obtain more accurate and precise values of K. Especially, some problems involved in determining the chemical yields were examined in detail. The proposed procedure was applied to some standard rock and meteorite samples, and the analytical results are confirmed to be mostly consistent with the literature data.
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Vekoslava STIBILJ, Marjan DERMELJ, Mladen FRANKO, Anthony R. BYRNE
1994 Volume 10 Issue 5 Pages
789-793
Published: October 10, 1994
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A spectrophotometric method for measuring the chemical yield in radiochemical neutron activation analysis of selenium in feedstuffs and biological materials is described. The method is based on measuring the absorbance at 350nm, which is due to the 5-nitro-2, 1, 3-benzoselenadiazole complex formed between selenium and 4-nitro-1, 2-diaminobenzene. The technique was checked against radiotracer techniques using
75Se or
81mSe, and was illustrated by results for different botanical samples and certified reference materials.
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Yutaka HAYASHIBE, Minoru TAKEYA, Yasumasa SAYAMA
1994 Volume 10 Issue 5 Pages
795-799
Published: October 10, 1994
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Flow-injection spectrophotometric analysis has been established for the determination of zinc at 1μg ml
-1 level in serum using 5-Br-PAPS(2-(5-bromo-2-pyridylazo)-5-[
N-n-propyl-
N-(3-sulfopropyl)amino]phenol, disodium salt) as a chromogenic reagent. A 100μl portion of serum is directly injected into the carrier stream containing 5%(v/v) TMAH (tetramethylammonium hydroxide) and 0.5M trisodium citrate. After mixing with 0.01%(w/v) 5-Br-PAPS-0.5M ammonium acetate-7.2×10
-3M salicylaldehyde oxime-1%(v/v) Triton X-100-0.5M hydrochloric acid solution, the absorbance of Zn-5-Br-PAPS complex is measured at 560nm. The proposed flow-injection system is fully controlled with a personal computer and permits 60 samples to be measured per hour. The relative standard deviation (
n=50) for 1.2μgZn ml
-1 solution is 3.3%.
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Isabel M. P. L. V. O. FERREIRA, José L. F. C. LIMA, Antó ...
1994 Volume 10 Issue 5 Pages
801-805
Published: October 10, 1994
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A flow injection system for the sequential determination of chloride and sodium in instant soups is described. The chloride is measured with a tubular chloride ion selective electrode with a membrane consisting of a homogeneous mixture of silver chloride and silver sulfide, and the sodium is measured by flame emission spectrometry. Results were in good agreement with the reference procedures and exhibited good precision (relative standard deviations less than 1.1%). The sampling rate was 150 samples per hour.
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Tetsutaro YOSHINAGA, Masaaki KOGA, Kentaro KAWANO
1994 Volume 10 Issue 5 Pages
807-812
Published: October 10, 1994
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Potentiometric titration was successfully applied for the determination of cyanamide (Cy) using a silver sulfide membranetype ion-selective electrode. In a Cy concentration range of 0.02 to 0.08M in a 1M NaOH solution, 98.9% of the cyanamide was recovered (RSD=0.08%,
n=10). The detection limit of Cy by the present method is around 6×10
-4M with a positive error of
ca. 1%, an RSD of 0.2%, and an n of 4. The coexistence of cyanoguanidine, urea, sulfide and chloride at a molar ratio of 0.3:1.5:0.3:1.0 to 1 part of Cy did not affect the determination of Cy.
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3-(β-D-Galactopyranosyloxy)-6-(4-methoxyphenyl)-2-methyl-imidazo[1, 2-α]pyrazine
Motohiro MITANI, Syujiro SAKAKI, Yasumi KOINUMA, Yoshiaki TOYA, Masano ...
1994 Volume 10 Issue 5 Pages
813-814
Published: 1994
Released on J-STAGE: July 27, 2007
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Katsuhisa MURAYAMA, Hiroshi NAKAMURA, Katsumi TAKAHASHI, Akira YOSHIDA
1994 Volume 10 Issue 5 Pages
815-816
Published: 1994
Released on J-STAGE: July 27, 2007
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Riyo TOMISAKI, Yoshinobu BABA, Mitsutomo TSUHAKO, Satoshi TAKAHASHI, K ...
1994 Volume 10 Issue 5 Pages
817-820
Published: 1994
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Shukuro IGARASHI, Kenji KUWAE, Takao YOTSUYANAGI
1994 Volume 10 Issue 5 Pages
821-822
Published: 1994
Released on J-STAGE: July 27, 2007
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Tadashi HARA, Hisashi NISHIDA, Riichiro NAKAJIMA
1994 Volume 10 Issue 5 Pages
823-825
Published: October 10, 1994
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Yoshikazu FUJITA, Itsuo MORI, Minako TOYODA, Takako MATSUO
1994 Volume 10 Issue 5 Pages
827-830
Published: October 10, 1994
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Takashi IKEGAMI, Hidetoshi ARAKAWA, Masako MAEDA, Akio TSUJI
1994 Volume 10 Issue 5 Pages
831-834
Published: October 10, 1994
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Masayuki UTO, Kokoro KODAMA, Kana ISHIMORI, Yoshihisa KUDO, Suwaru HOS ...
1994 Volume 10 Issue 5 Pages
835-837
Published: October 10, 1994
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