Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 20 , Issue 6
Showing 1-23 articles out of 23 articles from the selected issue
Rapid Communications
Original Papers
  • Satoshi SASAKI, Yoshikazu ARAI
    2004 Volume 20 Issue 6 Pages 895-898
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    Oscillation is found in many biological systems, and among them the enzymatic oscillatory reaction has been well studied using an enzyme solution. We show in this study for the first time that oscillation occurs when catalase is immobilized to controlled pore glass (CPG). The oscillatory wave mode changes with the distance among the CPG, electrode, or dialysis membrane. The lower substrate concentration results in oscillation with a longer period. This tendency agrees with a previous study using an enzyme solution. Furthermore, we show that the oscillation occurs when no dialysis membrane is used. These results show the wider applicability of the system to analysis or novel device fabrication.
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  • Marek TROJANOWICZ, Dario COMPAGNONE, Carla GONÇALES, Zbigniew J ...
    2004 Volume 20 Issue 6 Pages 899-904
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    The possibility of screening the mercury(II) content in real environmental samples based on inhibition of the activity of dissolved invertase has been examined. The extent of inhibition was measured with an amperometric glucose biosensor with glucose oxidase immobilized on a membrane. Data concerning the stability and reproducibility of measurements are provided. The effects of heavy metals on the inhibition of invertase, together with that of common anions such as chloride, nitrate and sulfate are reported. The determination of mercury using this procedure has been carried out in samples of natural and waste water samples of various origins already analyzed by ICP-AES, by spiking ppb levels of mercury(II). Differences in the inhibiting effect of the samples and in the recoveries were found and are discussed.
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  • Jing-Ming GONG, Xiang-Qin LIN
    2004 Volume 20 Issue 6 Pages 905-909
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A novel and effective approach to sensitively determine serotonin, known as 5-hydroxytryptamine (5-HT), has been proposed based on a 5,5-ditetradecyl-2-(2-trimethylammonioethyl)-1,3-dioxane bromide (DTDB) self-assembled lipid bilayer membrane modified glassy carbon electrode (DTDB/GCE). A DTDB/GCE shows the strong electrocatalysis for the oxidation of 5-HT, with the peak potential shifted to less positive value of 0.376 V vs. SCE, and effectively eliminates the interference from ascorbic acid (AA), even in the presence of 100-fold concentration of AA. Differential pulse voltammetry (DPV) gave a linear current for 5-HT from 2.0 × 10-7 to 1.0 × 10-5 M. At the DTDB/GCE, the oxidation of 5-HT was controlled by the adsorption process; for 5-HT coexisting with DA, the competitive adsorption was observed.
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  • H. IBRAHIM, Y. M. ISSA, Hazem M. ABU-SHAWISH
    2004 Volume 20 Issue 6 Pages 911-916
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A carbon-paste electrode for dicyclomine hydrochloride (DcCl) was prepared and fully characterized in terms of composition, life span, usable pH range and temperature. The electrode was applied to the potentiometric determination of dicylominium ion in its pure state and in pharmaceutical preparations in batch and flow injection conditions and in biological fluids using standard additions method. The electrode is based on a mixture of two ion-exchangers, namely, dicyclominium-phosphomolybdate and dicylominium-tetraphenylborate, dissolved in dioctyl phthalate as pasting liquid. The modified electrode showed a near-Nernstian slope of 58 ± 2 mV over the concentration range of 1.2 × 10-5 - 1.6 × 10-2 M with an average recovery of 97 - 102% and a RSD of 0.090 - 1.00. The electrode exhibits good selectivity for DcCl with respect to a large number of inorganic cations, sugars, amino acids and organic substances of biological fluids. Potentiometric titrations of DcCl with several titrants have been monitored using this modified carbon paste electrode as an end-point indicator electrode.
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  • Ali Reza GHIASVAND, Elham MOHAGHEGHZADEH
    2004 Volume 20 Issue 6 Pages 917-919
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A simple and efficient method for the selective separation and preconcentration of uranium(VI) using homogeneous liquid-liquid extraction was developed. Tri-n-octylphosphine oxide (TOPO) and tri-n-butylphosphate (TBP) were investigated as complexing ligands, and perfluorooctanoate ion (PFOA-) was applied as a phase separator agent under strongly acidic conditions. Under the optimal conditions ([PFOA- = 1.7 × 10-3 M, [TOPO] = 5.4 × 10-4 M, [HNO3] = 0.3 M, [acetone] = 3.2% v/v) 10 µg of uranium in 40 ml aqueous phase could be extracted quantitatively into 8 µl of the sedimented phase. The maximum concentration factor was 5000-fold. However, an effort for the quantitative extraction using TBP was inefficient and the percent recovery was at most 56.7. The influence of the type and concentration of acid solution, optimum amount of the ligand, type and volume of the organic solvent, concentration of PFOA, volume of the aqueous sample and effect of different diverse ions on the extraction and determination of uranium(VI) were investigated. The proposed method was applied to the extraction and determination of uranium(VI) in natural water samples.
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  • Taicheng DUAN, Hongfei LI, JianZhen KANG, Hangting CHEN
    2004 Volume 20 Issue 6 Pages 921-924
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    In this work, the feasibility of employing Cyanex 923 as an extractant into the non-cerium REE (rare earth elements) impurity analysis of high-purity cerium oxide was investigated. Through investigations on the choice of the extraction medium, the optimium extraction acidity, matrix Ce4+ effect on the non-cerium REE ion extraction, the optimium extractant concentration and suitable extracting time, and oscillation strengh, it was found that when the phase ratio was at 1:1 and the acicidity was about 2% H2SO4, by gently shaking by hand for about 2 min, 10 mL of 30% Cyanex 923 could not extract even for a 20 ng amount of non-cerium REE3+ ions. However, the extraction efficiency for Ce4+ of 100 mg total amount under the same conditions was about 96%, indicating that a 25-fold preconcentration factor could be achieved. Thus, it was concluded that Cyanex 923 could be used in a REE impurity analysis of 99.9999% or so pure cerium oxide for primary sepapation to elimilate matrix-induced interferences encountered in an ICP-MS (inductively coupled plasma mass spectroscopy) determination.
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  • B. Krishna REDDY, K. Janardhan REDDY, J. Rajesh KUMAR, A. Kiran KUMAR, ...
    2004 Volume 20 Issue 6 Pages 925-930
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A simple and highly sensitive method was developed for the extractive-spectrophotometric determination of palladium with benzilidithiosemicarbazone. The metal ion formed a reddish brown complex with benzildithiosemicarbazone in a potassium chloride-hydrochloric acid buffer of pH 2.5, which was easily extractable into methyl isobutyl ketone. The 1:1 complex showed the maximum absorbance at 395 nm with a Beer’s law range of 0.25 - 3.5 ppm. The molar absorptivity and Sandell’s sensitivity were found to be 3.018 × 104 dm3 mol-1 cm-1 and 0.0035 µg cm-2, respectively. The correlation coefficient of the Pd(II)-BDTSC complex was 0.998, which indicated an excellent linearity between the two variables. The repeatability of the method was checked by finding the relative standard deviation (RSD) (n = 10), which was 0.46%. The instability constant of the complex calculated from Edmond and Birnbaum’s method was 2.41 × 10-5, that of Asmus’ method is 2.53 × 10-5 at room temperature. The interfering effects of various cations and anions were studied. The proposed method was successfully applied to the determination of palladium(II) in synthetic mixtures and hydrogenation catalysts. The validity of the method was tested by comparing the results with those obtained using an atomic absorption spectrophotometer.
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  • V. D. MITIC, S. D. NIKOLIC, V. P. STANKOV-JOVANOVIC
    2004 Volume 20 Issue 6 Pages 931-934
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A new sensitive kinetic method has been developed for the determination of trace amounts of I- over the range of 50 - 300 ng cm-3. The method was based on the inhibitory effect of iodide on the oxidation of Victoria Blue 4-R by KBrO3. The reaction is monitored spectrophotometrically at 596.3 nm. Method development includes optimization of reagent concentration and temperature. The kinetic parameters of the reaction were reported and a rate equation was suggested. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The proposed method was successfully applied to the determination of iodide in real samples. The new developed method was found to have fairly good selectivity, sensitivity, simplicity and rapidity.
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  • Alfred A. CHRISTY, Sumaporn KASEMSUMRAN, Yiping DU, Yukihiro OZAKI
    2004 Volume 20 Issue 6 Pages 935-940
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A new procedure has been developed for the classification and quantification of the adulteration of pure olive oil by soya oil, sun flower oil, corn oil, walnut oil and hazelnut oil. The study was based on a chemometric analysis of the near-infrared (NIR) spectra of olive-oil mixtures containing different adulterants. The adulteration of olive oil was carefully carried out gravimetrically in a 4 mm quartz cuvette, starting with pure olive oil in the cuvette first. NIR spectra of the 525 adulterated mixtures were measured in the region of 12000 - 4000 cm-1. The spectra were subjected batch wise to multiplicative signal correction (MSC) before calculating the principal component (PCA) models. The MSC-corrected data were subjected to Savitzky-Golay smoothing and a mean normalization procedure before developing partial least-squares calibration (PLS) models. The results revealed that the models predicted the adulterants, corn oil, sun flower oil, soya oil, walnut oil and hazelnut oil involved in olive oil with error limits ±0.57, ±1.32, ±0.96, ±0.56 and ±0.57% weight/weight, respectively. Furthermore, the PCA developed models were able to classify unknown adulterated olive oil mixtures with almost 100% certainty. Quantification of the adulterants was carried out using their respective PLS models within the same error limits as mentioned above.
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  • Anil K. BISHNOI, Rameshwar DASS, Ram G. SHARMA
    2004 Volume 20 Issue 6 Pages 941-943
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    6-Chloro-3-hydroxy-2-(5′-methylfuryl)-4H-chromene-4-one (CHMFC) has been used as an analytical reagent for the spectrophotometric determination of molybdenum. Molybdenum(VI) in the presence of several cations, anions and complexing agents forms a yellow 1:2 complex with CHMFC. The complex is quantitatively extractable into 1,2-dichloroethane from 1 mol dm-3 acetic acid medium and is stable for more than 6 h. The complex shows an absorption maximum at 438 nm with a molar absorptivity of 5.36 × 104 dm3 mol-1 cm-1 and Sandell’s sensitivity equal to 0.0017 µg Mo cm-2. The method obeys Beer’s law up to 1.9 µg Mo ml-1. The relative standard deviations are 0.2% for solutions and 0.5 - 1.5% for solid samples. The method is simple, selective, precise and rapid, and has been satisfactorily applied to the micro determination of molybdenum in various synthetic and standard samples.
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  • Chang-Qing ZHU, Yu-Qin WU, Hong ZHENG, Jin-Long CHEN, Dong-Hui LI, Shu ...
    2004 Volume 20 Issue 6 Pages 945-949
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A near-infrared (near-IR) fluorescence quenching method was developed for the determination of nucleic acids in aqueous solution by using a cationic heptamethylene thiacyanine as a probe. The near-IR cationic cyanine showed maximum excitation and emission wavelengths at 800 and 825 nm, respectively, in the presence of Triton X-100; the fluorescence of the cyanine could be greatly quenched by DNA. The calibration graphs were linear over the range of 10 - 400 ng/mL for CT (calf thymus) DNA and over the range 5 - 400 ng/mL for FS (fish sperm) DNA under optimal conditions. The corresponding detection limits were 5.2 ng/mL for CT DNA and 2.5 ng/mL for FS DNA. The relative standard deviation (n = 8) was 3.1% for 75 ng/mL CT DNA and 2.2% for 75 ng/mL FS DNA, respectively. Preliminary research showed that the fluorescence quenching might be ascribed to the formation of dye aggregate facilitated by DNA.
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  • Suresh K. KUMAR, Prabhakara S. RAO, L. KRISHNAIAH, B. JAYARAJ, P. CHIR ...
    2004 Volume 20 Issue 6 Pages 951-953
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A simple and highly sensitive reagent of salicylaldehyde 3-oxobutanoylhydrazone (salicylaldehyde acetoacetic acid hydrazone, SAAH) was synthesized and studied for the spectrophotometric determination of nickel in detail. In the pH range 6, which greatly increased the selectivity, nickel reacted with SAAH to form a 1:1 yellow complex, having a sensitive absorption peak at 405 nm. Under the optimal conditions, Beer’s law was obeyed over the range from 0.0117 to 0.1174 µg cm-3. The apparent molar absorptivity was 3.025 × 105 dm3 mol-1 cm-1. The detection limit and the variation coefficient were found to be 1.752 ng cm-3 and 1.0%, respectively. The method has been applied to the quantitative determination of nickel in different alloys and leaves.
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  • Narinder K. AGNIHOTRI, Sonia RATNANI, Vinay K. SINGH, Har B. SINGH
    2004 Volume 20 Issue 6 Pages 955-959
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A selective and sensitive derivative photometric method has been developed for the determination of trace amounts of Zn2+ with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol in the presence of cetylpyridinium chloride, a cationic surfactant. The molar-absorption coefficient and analytical sensitivity of the 1:2 complex at 554 nm are 1.19 × 105 L mol-1 cm-1 and 0.56 ng mL-1, respectively. The detection limit is 1.96 × 10-2 ng mL-1 and Beer’s law is valid in the 0.02 - 0.66 µg mL-1 range of Zn2+. The developed derivative procedure, using the zero-crossing measurement approach, is applied for the rapid and selective simultaneous determination of Zn2+ and Cd2+ in the range of 0.06 - 0.66 and 0.20 - 1.60 µg mL-1, respectively. Complex matrices, including reference materials, environmental and biological samples and synthetic mixtures, have been successfully analyzed for trace amounts of the two metal ions.
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  • César Ricardo Teixeira TARLEY, Marco Aurélio Zezzi ARRUD ...
    2004 Volume 20 Issue 6 Pages 961-966
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    A new sensitive and low cost method for cadmium determination at µg l-1 levels that combines an on-line preconcentration system with the thermospray flame furnace atomic absorption spectrometry technique (TS-FF-AAS) is described in this work. Cadmium is preconcentrated from an acidic medium (pH 2.0) by forming a complex with ammonium O,O-diethyldithiophosphate (DDTP), which is then adsorbed onto polyurethane foam (PUF). The elution step is performed by using 80% (v/v) ethanol. The effects of the chemical and flow variables associated with the preconcentration were studied, such as the pH of formation of the Cd-DDTP complex, the DDTP concentration, the preconcentration and elution flow rate and the mass of adsorbent. The present method was operated in volume-mode (2 ml) and provided a linear range from 0.4 to 15.0 µg l-1 with a sample throughput of 16 h-1. The increase of power detection related to TS-FF-AAS by coupling the preconcentration system was confirmed by the enhancement of sensitivity (ca. 5 times), when compared to the value for TS-FF-AAS alone, thus achieving a low detection limit (0.12 µg l-1). The accuracy of the method was confirmed from analyses of spiked water samples and by the use of a reference technique (ETAAS). Certified biological materials were also used for the same purpose.
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  • Jieming ZOU, Zhiliang JIANG, Lisheng WANG, Tingsheng LI, Qinye LIU
    2004 Volume 20 Issue 6 Pages 967-970
    Published: 2004
    Released: November 11, 2004
    JOURNALS FREE ACCESS
    There is a fluorescence peak at 570 nm, and a maximum absorption peak at 560 nm for phloxine (PHLO) in a pH 7 water solution. Under these conditions, the ciprofloxacin cation (CPFX+) and PHLO- combine into hydrophobic CPFX-PHLO association molecule by means of static gravitation. There are stronger van der Waals forces and hydrophobic forces among the CPFX-PHLO molecules. Thus, they aggregate automatically to the (CPFX-PHLO)n association nanoparticle in red-violet color. That was characterized by scan electron microscopy (SEM), hyperfiltration and dialysis tests. In 0.04 M HCl, the red-violet nanoparticles exhibited a Rayleigh scattering peak at 470 nm, a resonance scattering peak at 580 nm, a maximum absorption wavelength at 565 nm, and a fluorescence peak at 450 nm. The fluorescence analytical conditions of CPFX have been considered. The CPFX concentration in the range of 1.0 × 10-6 - 4.0 × 10-5 M is linear to the fluorescence intensity, F450nm. The detection limit was achieved at 4.0 × 10-7 M CPFX. The CPFX in real samples was determined with satisfactory results.
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