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Showing papers in "Analytical Sciences in 1988"


Journal ArticleDOI
TL;DR: In this paper, the authors performed rare earth element (REE) determinations with high accuracy and precision on four geological standard rocks by inductively coupled plasma-mass spectrometry (ICP-MS).
Abstract: Rare earth element (REE) determinations with high accuracy and precision were performed on four geological standard rocks (JA-1, JB-1, -2 and -3) by inductively coupled plasma-mass spectrometry (ICP-MS). In order to achieve this, internal standardization, matrix matching or separation of REE from the matrix elements are recommended. In these analyses, REE data obtained by ICP-MS show excellent agreement (within 5%) with those obtained by isotope dilution method using thermal ionization mass spectrometer. Among these analytical methods of ICP-MS, the most reliable data can be obtained by analysis using a sample solution free from matrix elements.

63 citations


Journal ArticleDOI
TL;DR: A highly sensitive high performance liquid chromatographic method with fluorometric postcolumn labeling using 2-cyanoacetamide was developed for determination of unsaturated disaccharides produced enzymatically from chondroitin sulfates (ChS).
Abstract: A highly sensitive high performance liquid chromatographic method with fluorometric postcolumn labeling using 2-cyanoacetamide was developed for determination of unsaturated disaccharides produced enzymatically from chondroitin sulfates (ChS). The calibration curves of the unsaturated disaccharides were linear over the range from 2pmol to 5nmol. This method was applied to the analysis of normal rabbit plasma for ChS to verify the sensitivity and practicality.

60 citations



Journal ArticleDOI
TL;DR: The selectivity coefficients KPotij with respect to the most common ions are compared to calculated values Kpotij, max required for measurements in intra-and extracellular samples without significant interference and these required values are fully met for H+, K+, Mg2+, Ca2+ and Cl-, while in the case of extrace cellular measurements H+, Na+, K+ and Ca2- can be assayed adequately.
Abstract: At present, neutral-carrier-and ion-exchanger-based ion-selective liquid membrane microelectrodes are available for the measurement of H+, Li+, Na+, K+, Mg2+, Ca2+, NH4+ and Cl-. Fundamental aspects, design features and limitations of microelectrodes are discussed and examples for their application in physiology are given. The most important characteristics are summarized in view of intra-and extracellular physiological measurements. The selectivity coefficients KPotij with respect to the most common ions are compared to calculated values Kpotij, max required for measurements in intra-and extracellular samples without significant interference. For intracellular microelectrode studies, these required values are fully met for H+, K+, Mg2+, Ca2+ and Cl-, while in the case of extracellular measurements H+, Na+, K+ and Ca2+ can be assayed adequately.

42 citations


Journal ArticleDOI
TL;DR: In this paper, a new speciation scheme was proposed using sorption on the DEAE-Sephadex A-25 anion-exchanger and the indium-treated Amberlite XAD-2 resin as well as filtration.
Abstract: Iron may exist in river water as colloidal and suspended particles, generally associated with humic substances, clay and silica. A new Speciation scheme is proposed using sorption on the DEAE-Sephadex A-25 anion-exchanger and the indium-treated Amberlite XAD-2 resin as well as filtration. Several composite particles have been artificially prepared to simulate natural particles and their sorption behavior has been examined. In the river water examined, about half of the dissolved iron species (the fraction which passes a 1-μm filter) was negatively charged humic colloids, most of which contained clay, while the remainder were essentially inorganic colloids, which included negatively charged aggregates of hydrated iron(III) oxide and clay (or silica) as well as positively charged hydrated iron(III) oxide. The correlation of copper with iron is also discussed.

40 citations


Journal ArticleDOI
TL;DR: In this paper, the results of a preliminary study on direct analysis of solid metals and nonconductive samples by inductively coupled plasma mass spectrometry (ICP-MS) are described.
Abstract: The results of a preliminary study on direct analysis of solid metals and nonconductive samples by inductively coupled plasma mass spectrometry (ICP-MS) are described. The aerosols ablated from solid samples by a ruby laser are introduced into an inductively coupled plasma, with detection of the resulting ions by a mass spectrometer. With conventional solution introduction, polyatomic species from mineral acids and solvents prevent the accurate determination of some trace analytes. However, using laser ablation, these background peaks are greatly reduced. The relative sensitivity factors for the laser ablation method are seen to vary from unity, with volatile elements such as Pb and Bi being more sensitive. Detection limits of rare-earth elements, Th and U in silicate rocks are excellent (0.02-0.9ppm at the effective integrating time of 1.4s), being better than those of the examined elements in steel (1.7-29ppm at the effective integrating time of 0.6s).

37 citations


Journal ArticleDOI
TL;DR: In this paper, a mathematical model of a biocatalyst electrode with entrapped mediator is presented to simulate the dependence of the steady-state current, I, on the concentration of the substrate at the surface of the enzyme layer, 1cs, and on the concentrations of the mediator in the enabler layer, CM.
Abstract: A mathematical model of a biocatalyst electrode with entrapped mediator is presented. Differential equations describing the diffusion of the substrate and mediator coupled with the enzyme reaction in the immobilized enzyme layer adjacent to the electrode surface are numerically solved to simulate the dependence of the steady-state current, I, on the concentration of the substrate at the surface of the enzyme layer, 1cs, and on the concentration of the mediator entrapped in the enzyme layer, CM. The numerical solutions are expressed by Michaelis-Menten type equations with three parameters which characterize the I vs. 1cs and I vs. CM curves. The diffusional resistance of a semipermeable membrane covering the enzyme layer on the electrode surface is also taken into consideration. The dependence of the current on the potential applied to the electrode, E, is also derived and the parameters characterizing the I vs. E curve are discussed.

36 citations


Journal ArticleDOI
TL;DR: The gate surface of an ion-sensitive field effect transistor (ISFET) was covered with a penicillinase-adsorbed Langmuir-Blodgett (LB) membrane in order to examine the potentiometric response to H+ ion andPenicillin G.
Abstract: The gate surface of an ion-sensitive field effect transistor (ISFET) was covered with a penicillinase-adsorbed Langmuir-Blodgett (LB) membrane in order to examine the potentiometric response to H+ ion and penicillin G. The LB membrane-modified ISFET exhibited pH response of -30--40mV/pH, whereas near-Nernstian response was obserbed for the ISFET without LB membrane. The ISFET penicillin sensor showed the potentiometric response to penicillin G at milimolar level in 5mM phosphate buffer. The penicillin sensor could be used to determine penicillin G for more than 12 days without any deterioration.

34 citations


Journal ArticleDOI
TL;DR: In this paper, an integrated spectral data base system named SDBS was constructed, in which six kinds of spectral data, i.e., data of IR, MS, 1H-NMR, 13C- NMR, ESR and Raman spectra were compiled in an integrated way under the control of a directory data base.
Abstract: An integrated spectral data base system named SDBS was constructed, in which six kinds of spectral data, i.e., data of IR, MS, 1H-NMR, 13C-NMR, ESR and Raman spectra were compiled in an integrated way under the control of a directory data base. The spectra data are full pattern data and/or numerical data depending on the features of the spectra, most of which were obtained in our laboratory. Three options are provided as mode of access. In LOOK option the spectra for a given compound are displayed; in SEARCH option the identification of unknown compounds as well as the estimation of NMR chemical shifts and/or of the sub-structure of a molecule are possible; and in SIMULATE option, 1H-NMR and ESR spectra are generated from the NMR and ESR parameters, respectively. At present, approximately 17000 compounds are registered in the directory data base.

32 citations


Journal ArticleDOI
TL;DR: In this paper, the authors reported the HPLC microanalytical method for brassinosteroids as their bisnaphthaleneboronate derivatives and its application to the identification of brassinolide in the pollen of broad bean (Vicia faba L).
Abstract: Since the discovery of brassinolide as a new plant growth hormonal steroid', a number of its related steroids (general term, brassinosteroids) have been found to occur in higher plants.2 Because of its remarkable biological activities and the very small amounts contained in plants2, microanalytical methods have been necessary for their screening and identification of brassinosteroids in plants. In our previous paper3, we reported that bismethaneboronates of brassinosteroids are useful derivatives for gas chromatography and gas chromatography-mass spectrometry. Our microanalytical method has been useful for the demonstration of the ubiquitous distribution of these hormonal steroids in the plant kingdom.4,5 However, high performance liquid chromatography (HPLC) analysis of brassinosteroids has not been intensively investigated, not withstanding the hope that more sensitive and selective analysis may be obtained by photometric or fluorimetric detection. The liquid chromatographic behavior of standard brassinosteroids was monitored with UV detector at 204 nm by Yokota et al.6 Because of the lack of the other UV active chromophore in brassinosteroids, derivatization is indispensable for their HPLC microanalysis. After employing a number of derivatization reagents, we have found that bisnaphthaleneboronate is a suitable derivative for brassinosteroids in HPLC analysis, due to the selectivity of 1-naphthaleneboronic acid for the two vicinal diol functional group of the steroids. In this paper, we report the HPLC microanalytical method for brassinosteroids as their bisnaphthaleneboronate derivatives and its application to the identification of brassinolide in the pollen of broad bean (Vicia faba L.) as a demonstration of the usefulness of our microanalytical method. Experimental

30 citations


Journal ArticleDOI
TL;DR: In this article, an electrochemiluminescence method was developed for determination of sub-nmol hydrogen peroxide in aqueous solution, which emitted light of the maximum wavelength of 436nm with a half-life of less than 0.2s from the electrode surface.
Abstract: An electrochemiluminescence method was developed for determination of sub-nmol hydrogen peroxide in aqueous solution. Luminol was electrochemically oxidized, then reacted with hydrogen peroxide; it emitted light of the maximum wavelength of 436nm with a half-life of less than 0.2s from the electrode surface. In flow injection analysis a carrier solution (phosphate buffer, pH 7-9) containing 17μM luminol was delivered at the flow rate of 0.5ml/min. The luminescence was detected by a photon counter in a spiral cell under the applied potential of 0.7V vs. SCE. A straight line calibration plot was obtained with good reproducibility [RSD 1.6% (n=5)] in the concentration range of 0.066 to 0.6nmol.


Journal ArticleDOI
TL;DR: In this paper, a reversed-phase high performance liquid chromatography (HPLC) method was proposed for the simultaneous determination of copper(II) chlorophyll a and b. This method can be performed within a short time period, thus facilitating an accurate routine assay of many samples.
Abstract: Copper(II) chlorophyll a and b, i.e. (pheophytinato a)copper(II) and (pheophytinato b)copper(II), were prepared and purified by semi-preparative reversed-phase high performance liquid chromatography (HPLC). The spectroscopic properties of these compounds, which so far have been little studied, are given in detail. Separation of copper(II) chlorophyll a and b is achieved with a C18-bonded silica column and a mobile phase of acetone-acetonitrile (50:50, v/v). A rapid and accurate HPLC method with visible detection at 425nm has been proposed for the simultaneous determination of copper(II) chlorophyll a and b. Both calibration graphs for copper(II) chlorophyll a and b are linear in the concentration range 0-10μg cm-3. The detection limits of copper(II) chlorophyll a and b are 4.4ng cm-3 within 3.1% relative standard deviation (RSD) (n=10) and 2.3ng cm-3) within 3.3% RSD (n=10), respectively. The HPLC method proposed here has also been evaluated in comparison to the spectrophotometric method. This reversed-phase HPLC method can be performed within a short time period, thus facilitating an accurate routine assay of many samples.

Journal ArticleDOI
TL;DR: In this article, it was shown that o-phthalaldehyde reacts with some kinds of nucleophiles, such as thiolsl, sulfite ion2, and cyanide ion3 in the presence of amines or amino acids to afford the highly fluorescent isoindole derivatives.
Abstract: It is well known that o-phthalaldehyde (OPA) reacts with some kinds of nucleophiles, such as thiolsl, sulfite ion2, and cyanide ion3 in the presence of amines or amino acids to afford the highly fluorescent isoindole derivatives. Furthermore, in the course of seeking new and improved fluorogenic reagents, the group at the University of Kansas4-' found that 2,3-naphthalenedicarboxaldehyde (NDA) reacted with amino acids in the

Journal ArticleDOI
TL;DR: In this article, a methode d'analyse par le dosage de 3 hormones is presented, and conditions experimentales are described, and a montage et des conditions experimentale are described.
Abstract: Description du montage et des conditions experimentales. Illustration de la methode d'analyse par le dosage de 3 hormones

Journal ArticleDOI
TL;DR: In this paper, a 150 mm long Zorbax SIL column with 2.1mm i.d. was used to separate the alkali metal cations on a silica gel column by cation exchange.
Abstract: Alkali metal cations were shown to be separable on a silica gel column by cation exchange. Factors affecting the separation of these cations were investigated. Among them, type and concentration of the mobile phase electrolytes profoundly affected the retention of the analyte. The alkali metal cations were well separated on a 150 mm long Zorbax SIL column with 2.1mm i.d., using an aqueous 0.01mol dm(-3) lithium acetate as the mobile phase. Sodium and potassium in river water were determined rapidly with satisfactory accuracy.

Journal ArticleDOI
TL;DR: Amberlite XAD copolymers have been used as adsorbents for organic substances and as supports for Chelating agent-impregnated resin (CIR) as mentioned in this paper.
Abstract: Amberlite XAD copolymers have been used as adsorbents for organic substances and as supports for Chelating agent-impregnated resin(CIR). The adsorption mechanism and behavior of 8-hydroxyquinoline (8HQ) and its derivatives on XAD resins have been investigated by interpreting the distribution coefficients (Kd) measured under various conditions. The logKd values of 8HQ and its four derivatives on XAD resins were found to increase up to the certain pH values, and then to decrease with increasing pH. The pH values having maximum logKd values are very close to their isoelectric points. The adsorption of 8HQ and its derivatives was due to molecular adsorption, because the adsorption became maximum when they existed as electrically neutral molecules. Amberlite XAD resins (XAD-2, -4 and -7) impregnated with chelating agents, such as 8HQ, 5, 7-dihalo-8-hydroxyquinoline (DXHQ) and 2-methyl-8-hydroxyquinoline (MHQ), have been applied as CIR resins to the adsorption, separation, concentration and recovery of metal ions (Cu, Cd, Ni, Zn, Pb, Hg and Fe) from the aqueous solutions. All CIR resins show relatively good resistance to leaching at the pH range of 3-10. The magnitude of adsorption capacity of CIR depends on the impregnating capacity of the CIR and the adsorption mole ratio at the optimum pH condition. The metal ions adsorbed by CIR were quantitatively recovered with 3-5M hydrochloric acid. Some examples of selective separation and concentration of metal ions were performed by using CIR resins.


Journal ArticleDOI
TL;DR: Inductively coupled plasma-mass spectrometry is a rapidly growing technique for multi-elemental analysis as mentioned in this paper, and instrumental developments, analytical performance and applications of this method achieved recently are described.
Abstract: Inductively coupled plasma-mass spectrometry is a rapidly growing technique for multi-elemental analysis. In this review, instrumental developments, analytical performance and applications of this method achieved recently are described. Ion sampling interface, ion lens systems and various sample introduction systems are discussed. Suppression of analyte signals is usually observed in the presence of matrix salts at high concentration; this effect is generally more serious than those observed in inductively coupled plasma atomic emission spectrometry. The dependency of the suppression effect on the atomic weight of matrix elements is discussed. Applications to real samples for the determination of trace elements and isotope ratios are described.

Journal ArticleDOI
TL;DR: Evaluation des capacites d'adsorption de quelques nouvelles ceramiques utilisees comme materiau de garnissage de colonnes chromatographiques as mentioned in this paper.
Abstract: Evaluation des capacites d'adsorption de quelques nouvelles ceramiques utilisees comme materiau de garnissage de colonnes chromatographiques

Journal ArticleDOI
TL;DR: In this article, a detailed study has been made for the extractive spectrophotometric determination of up to 2.8ppm of palladium(II) in the presence of chloride ions.
Abstract: The spectrophotometric characteristics of the complexes formed with di-2-pyridylmethanone 2-(5-nitro)pyridylhydrazone (DPNPH) and eight metal ions are reported. The reagent appears to be promising especially for palladium(II) and cobalt(II) in selectivity and for copper(II), nickel(II), zinc(II) and cadmium(II) in sensitivity. A detailed study has been made for the extractive spectrophotometric determination of up to 2.8ppm of palladium(II) in the presence of chloride ions. The molar absorptivity of the complex extracted into 1, 2-dichloroethane is 3.78×104l mol-1 cm-1 at 560nm. The method is satisfactorily applied to the determination of palladium in some palladium catalysts.

Journal ArticleDOI
TL;DR: A high performance liquid chromatographic method involving postcolumn photochemical reaction and fluorometric detection has been developed for the determination of kynurenic acid in human serum at concentrations as low as 0.05pmol/100μl.
Abstract: A high performance liquid chromatographic method involving postcolumn photochemical reaction and fluorometric detection has been developed for the determination of kynurenic acid. Kynurenic acid was separated on a reversed phase column with a mobile phase containing hydrogen peroxide and irradiated by ultraviolet light to give fluorescence. The method allows the determination of kynurenic acid in human serum at concentrations as low as 0.05pmol/100μl.

Journal ArticleDOI
Sadao Mori1
TL;DR: In this article, a mixture of low and high-conversion styrene-methyl methacrylate random copolymers, P(S-MMA), were fractionated by size exclusion chromatography (SEC).
Abstract: Low- and high-conversion styrene-methyl methacrylate random copolymers, P(S-MMA), were fractionated by size exclusion chromatography (SEC). Each fraction was subjected to liquid adsorption chromatography (LAC) using silica gel as an adsorbent and a mixture of chloroform and ethanol as the mobile phase. In low-conversion P(S-MMA), the differences of peak composition of LAC chromatograms for SEC fractions were 4-5% and the difference between the highest and the lowest styrene content in components was about 10%. CCD became broader with decreasing molecular size. One sample of low-conversion P(S-MMA) showed two peaks in a LAC chromatogram, showing that this sample was a mixture of two copolymers of different compositions. LAC peaks of SEC fractions for high-conversion P(S-MMA) were broad compared to low-conversion ones; the difference of peak composition for one sample was 11% and the range of composition was between 21 and 52% styrene. LAC is a very useful technique for obtaining CCD of copolymers and compositional differences in a sample.


Journal ArticleDOI
TL;DR: In this paper, the authors present a preliminary result of ESR microscopic imaging which utilizes a localized microwave magnetic field produced at the surface of a specimen using a cavity with a pinhole.
Abstract: Electron spin resonance (ESR) widely used in analytical sciences has become a method of dating and analysis in geosciences, archaeology and forensic science.' We are involved in an ESR study of some geological materials and came across the necessity to determine the distribution of some paramagnetic species. The spatial distribution of paramagnetic species is obtained in ESR imaging by utilizing the additional linear magnetic filed gradient superimposed on a uniform magnetic field. Although the basic idea of this method is the same as that in magnetic resonance imaging (MRI) or NMR imaging, some problems arise in ESR imaging from the lineshape of ESR signals. The broad linewidth and hyperfine structure in ESR signals make ESR imaging more difficult than NMR imaging. ESR imaging of specimens which contain several paramagnetic species is especially complicated.2 Several investigations to solve these problems have been reported. The field gradient coils have been inserted in the microwave cavity to obtain the high field gradient and high spatial resolution. Microscopic imaging of radiation-induced defects in NaCI was reported as an example of microdosimetry.3 In another trial, the localized modulation field was scanned mechanically in the microwave cavity instead of using a magnetic field gradient to obtain the surface distribution of paramagnetic species, especially alanine radicals in ESR dosimetry.4 In these new trials, the characteristic feature was to use the localized magnetic field at a pin-hole region to obtain the microscopic ESR image rather than the magnetic field gradient used in MRI. In this letter, we present a preliminary result of ESR microscopic imaging which utilizes a localized microwave magnetic field produced at the surface of a specimen using a cavity with a pin-hole. We have localized the microwave magnetic field for ESR. The resolution of this imaging method does not depend on the lineshape of signals but on the shape and size of a pin-hole in the cavity. Two-dimensional ESR image at the flat surface of a carbonate fossil, crinoid, is shown as a demonstration of the present surface scanning microscope system. Experimental

Journal ArticleDOI
TL;DR: In this article, the utility of microwave oven for simple and rapid acid digestion of zoological and botanical materials was investigated by using a double Teflon vessel with a polypropylene jacket.
Abstract: The utility of microwave oven for simple and rapid acid digestion of zoological and botanical materials was investigated by using a double Teflon vessel with a polypropylene jacket. The microwave-assisted digestion of samples with the HNO3-HCl-HClO4-HF mixture in the bomb offers the advantage of taking much shorter process for sample preparation. The digestion was completed within 15min even under a very mild condition. Eight elements (Cu, Fe, Mn, Zn, Ca, Mg, K and Na) in the standard reference materials, NBS-SRM 1577 Bovine Liver and NIES-CRM No. 1 Pepperbush, No. 6 Mussel and No. 7 Tea leaves, were determined by one-drop flame atomic absorption and emission spectrometry. Good agreement with the certified values was obtained.


Journal ArticleDOI
TL;DR: In this paper, a batchwise ligand vapor method was used to prevent any beryllium acetylacetonate from remaining in the gas chromatographic column, which was applied to the determination of Be in lake water samples.
Abstract: The determination of Be in natural water by gas chromatography-helium microwave induced plasma emission spectrometry is described. Beryllium was concentrated about 230 times by the extraction with acetylacetone into chloroform and by further evaporation of the solvent. A batchwise ligand vapor method was used to prevent any beryllium acetylacetonate from remaining in the gas chromatographic column. The detection limit was 10pg in 30ml of water sample and the relative standard deviation was 4.1% at 10ng of Be. The method was applied to the determination of Be in lake water samples.

Journal ArticleDOI
TL;DR: In this article, a new method of flotation separation and preconcentration of vanadium traces is described, where the ion-associate formed by the anionic vanadium(V)-3, 5-dinitrocatechol complex and Rhodamine B is floated with cyclohexane.
Abstract: A new method of flotation separation and preconcentration of vanadium traces is described. The ion-associate formed by the anionic vanadium(V)-3, 5-dinitrocatechol complex and Rhodamine B is floated with cyclohexane. The separated and washed compound readily dissolves in acetone, giving an intensely coloured solution which forms the basis for a sensitive spectrophotometric determination of vanadium. The molar absorptivity is 2.1×105l mol-1 cm-1 at 555nm and the detection limit is 3ng/ml. Beer′s law is obeyed up to a vanadium concentration of 0.3μg/ml. The composition of the floated compound was established. Its proposed formula is [(RB)2]- [VO(OH)(DNC)2]. EDTA, oxalate and some metals interfere. The method becomes specific for vanadium after a preliminary extraction of the metal as its N-benzoyl-N-phenylhydroxylamine (BPHA) chelate from a HCl-HF medium. The method was applied to the vanadium determination (0.2-9ppm) in some vegetables.

Journal ArticleDOI
TL;DR: In this article, a flow injection analytical method is proposed for the spectrophotometric determination of trace amounts of bromide based on its catalytic effect on the oxidation of Pyrocatechol Violet by hydrogen peroxide in strongly acidic solution.
Abstract: A flow injection analytical method is proposed for the spectrophotometric determination of trace amounts of bromide based on its catalytic effect on the oxidation of Pyrocatechol Violet by hydrogen peroxide in strongly acidic solution. Bromide in water samples can be determined at a sampling rate of 45h-1 with 500μl sample injections. The detection limit is 10μg l-1 and the calibration graph for bromide is linear over the range of 10-600μg l-1. The relative standard deviations are 2.5% for 20μg l-1 bromide and 1.4% for 105μg l-1 bromide. The procedure is applied successfully to the determination of bromide in natural waters.