Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 26 , Issue 1
Showing 1-23 articles out of 23 articles from the selected issue
Reviews
  • Munetaka OYAMA
    Type: Reviews
    2010 Volume 26 Issue 1 Pages 1-12
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Increasing attention has been devoted to the use of metal nanoparticles (NPs) for electroanalysis. To make the best use of the electrocatalytic and electron-conducting characteristics of metal NPs, various nanoarchitectures have been developed for modifying metal NPs on electrode surfaces. In this review, at first recent nanoarchitectures with metal NPs for modifying electrodes are summarized together with the results of electrochemical analysis. Then, the progress of a seed-mediated growth method that we developed for modifying electrode surfaces is shown as an example that the nanoarchitectures of metal NPs are possible without using organic linker molecules. This approach should be effective for further functional modifications of the surfaces of metal NPs as well as the electrochemical analysis with lower charge-transfer resistance.
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Original Papers
  • Md. Monirul ISLAM, Kosei UENO, Saulius JUODKAZIS, Yukie YOKOTA, Hiroak ...
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 13-18
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Interdigitated array electrodes with surface-enhanced Raman scattering (SERS) functionality for in situ qualitative and quantitative analysis of electroactive species are demonstrated. Gold nanostructured interdigitated array electrodes (NIDAEs) were fabricated by electron beam lithography, and used for an electrochemical SERS study of K3[Fe(CN6)] in aqueous KClO4 solution in single and generation-collection modes. The generation-collection mode experiment showed amplification of the SERS band intensity for adsorbed ferricyanide ions at the negative end of the applied potential, while in single mode it was reduced to near zero. This new finding reveals that NIDAEs offer a new opportunity for analytical science by improving analytical sensitivity and detection ability of electroactive species. The electric fields accumulating at nanogaps are promising for manipulating linear and nonlinear optical phenomena. In addition, miniaturized NIDAEs are of great importance for developing lab-on-a-chip devices, and are useful for measurements within small space/volume domains, requiring only small amounts and/or concentrations of analytes.
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  • Md. Monirul ISLAM, Kosei UENO, Hiroaki MISAWA
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 19-24
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Nanostructured interdigitated array (IDA) electrodes with different inter-electrode spacing were demonstrated to improve the detection sensitivity of short-lived electroactive species and to follow interfacial dynamics by their surface-enhanced Raman scattering (SERS) functionality. Nanostructured IDA electrodes fabricated using electron beam lithography were used for an electrochemical SERS study of irreversible electroactive species, crystal violet (CV), in an aqueous KCl solution in single and generation-collection (GC) mode experiments. The GC mode enabled us to amplify the SERS intensity. An inter-electrode spacing dependent study found the maximum number of redox cycling, collection efficiency and amplification of the SERS intensity. Its SERS function disclosed the potential-dependent dynamics of CV molecules at the electrode surface, which was not observed in the redox current. Miniaturized nanostructured IDA electrodes are of great importance for developing lab on chip devices, and are useful for analyzing dynamical features within small space/volume domains, which require small amounts and/or concentration of analytes.
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  • Hideyuki MATSUTA, Kazuaki WAGATSUMA, Kuniyuki KITAGAWA
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 25-31
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Optogalvanic (OG) spectra of argon in the visible to near-infrared spectral region between 735 and 850 nm were investigated using a Grimm-style glow-discharge tube, which has been widely used to obtain depth profiles of the elemental composition on various film-like samples. About 49 lines of one-photon and two-photon OG peaks were observed with a pulsed Ti:sapphire laser; these peaks were precisely assigned. Two-photon OG spectra of argon were easily observed without focusing the pulsed laser irradiation to more than 1 mJ. The excitation mechanisms of the observed argon OG spectra could be classified into 3 types: single-photon transition, two-photon transition, and two-photon stepwise transition. In addition, a pseudo-resonant effect was also found to be effective. The argon lines observed in this experiment are suitable as convenient calibration wavelength markers of pulsed tunable laser radiation.
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  • Kyoko YOSHIOKA, Yukari SATO, Mutsuo TANAKA, Teiichi MURAKAMI, Osamu NI ...
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 33-37
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Tri(ethylene glycol) terminated short alkylchain thiols (TEGCnSHs) offer good potential for constructing ultra-thin protein-resistant monolayers because they have an alkylchain for forming a densely packed monolayer and a flexible-hydrophilic oligo ethylene glycol arm for avoiding non-specific adsorption. Hybrid monolayers consisting of TEGCnSH and a maltoside ligand (MalC12SH, for capturing lectin) were effective in detecting concanavalin A (Con A). This hybrid monolayer was more suitable for Con A detection than that modified with 100% ligands in terms of the detection limit and time. The anti-fouling properties, packing densities, interaction and homogeneity of TEGCnSH monolayers were confirmed in detail by surface plasmon resonance (SPR) measurements and electrochemical methods. SPR measurements revealed their excellent repellency to proteins and peptides of various sizes (MW 400 − 104000). The electrochemical results indicated that the lower defects in the TEGCnSH monolayers suppressed the permeation of small peptides. The stability, homogeneity and packing density of the TEGCnSH monolayers were gradually improved as their alkylchain length increased.
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  • In-Hyeong YEO, Sun WEN, Sun-il MHO
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 39-44
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    The electrochemical activities of PbO2 thin-film electrodes were systematically studied with an oxygen-transfer reaction, i.e., the oxidation of thiourea. Five different types of PbO2 film electrodes were prepared using various methods to investigate the influence of the interfacial oxide layer formed between the Ti substrate and the PbO2 layer contacting the electrolyte. Among the electrodes tested, PbO2 electrode prepared by minimizing the formation of the interfacial oxide by either the electrochemical or thermal decomposition method generally exhibited better electrochemical activity. From the results, it can be inferred that the enhanced electrochemical activity of the electrode is due to minimization of the interfacial resistance by the introduction of a metallic Pb layer between the Ti substrate and the PbO2 layer, and to an increase in the roughness on the surface of the PbO2 layer.
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  • S. I. M. ZAYED, Y. M. ISSA
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 45-49
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    The construction and electrochemical response characteristics of two new polyvinyl chloride (PVC) membrane sensors for the determination of sibutramine hydrochloride were described. The sensors are based on the ion association complexes of sibutramine with sodium tetraphenylborate (NaTPB) or phosphotungstic acid (PTA) using dibutyl phthalate as plasticizing solvent. The sensors display a fast, stable response over the concentration range 3.84 × 10−5 − 1.00 × 10−2 M sibutramine hydrochloride monohydrate (SibuCl), with cationic slopes of 57.7 ± 0.57 and 59.7 ± 1.79 mV concentration decade−1 and detection limits of 8.91 × 10−6 and 1.47 × 10−5 M in case of sibutramine-tetraphenylborate (Sibu-TPB) and sibutramine-phosphotungstate ((Sibu)3-PT), respectively. The proposed sensors have been successfully applied for the determination of sibutramine hydrochloride in Regitrim capsules in batch and flow injection (FI) conditions.
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  • Gabriella RODA, Clelia DALLANOCE, Giovanni GRAZIOSO, Vincenzo LIBERTI, ...
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 51-54
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    The dissociation constants of epiboxidine 2 and a series of bases active at neuronal nicotinic acetylcholine receptors were determined by means of potentiometric and electrophoretic methods, which gave values in good agreement. Although showing different features, the two techniques are complementary for dissociation constant determinations. The choice of the most suitable method is guided by the available amount of sample, its purity, and the time needed for the analysis. The experimental values were compared with the predictions obtained with ACD/pKa DB software.
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  • Komandoor E. ACHYUTHAN, David G. WHITTEN, Darren W. BRANCH
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 55-61
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Supramolecular self-assembling cyanine and spermine binding to genomic DNA was a model for DNA–drug interactions during high throughput screening. Spermine competitively inhibited the self-assembly of cyanine upon DNA scaffolds as signaled by decreased fluorescence from the DNA–cyanine J-aggregate. The sequence of DNA exposure to cyanine or spermine was critical in determining the magnitude of inhibition. Methanol potentiated spermine inhibition by >10-fold. The IC50 and association constant (Ka) in 16% methanol were 0.35 ± 0.03 μM and 2.86 × 106 M−1 respectively, relative to 3.97 ± 0.47 μM and 0.25 × 106 M−1 respectively, in buffer. Increasing concentrations of cyanine overcame spermine inhibition, demonstrating the reversibility of DNA–drug interactions. λDNA interacted similarly with spermine and cyanine, confirming system flexibility. The model drug, dye and methanol effects are discussed in detail. Cyanine might be a safer alternative to the mutagenic ethidium bromide for investigating DNA–drug interactions.
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  • Jana ZDAROVA KARASOVA, Ladislav NOVOTNY, Karel ANTOS, Helena ZIVNA, Ka ...
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 63-67
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A simple and reliable HPLC method for determination of rat plasma levels of clinically used acetylcholinesterase (AChE) reactivators (HI-6 and obidoxime) is presented in our study. Separation was carried out by HPLC using an octadecyl silica stationary phase and a mobile phase consisting of 24% acetonitrile and containing 5 mM sodium octanesulfonate and 5 mM tetramethylammonium chloride (pH 2.3). Following intramuscular administration of equimolar doses of both oximes (22.23 mg/kg), the maximum of HI-6 concentration in rat plasma was reached in about 20 min giving 15.26 ± 1.71 μg/mL. The distribution of obidoxime was fast; the single maximum 23.62 ± 3.563 μg/mL was recorded at about 10 min. HPLC with UV detection presented in our study is a general method which could be applied for quick measurements of bisquaternary AChE reactivators in rat plasma.
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  • Supaporn KRADTAP HARTWELL, Apichart BOONMALAI, Prachya KONGTAWELERT, K ...
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 69-74
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A sequential injection capillary immunoassay system (SI-CI) was developed to automate the multi-step competitive bioassay procedures for hyaluronan (HA), a potential biomarker for liver and cancer diseases. Biotinylated HA-binding proteins (b-HABPs), anti-biotin conjugated with horseradish peroxidase (anti-b-HRP) and substrate 3,3′,5,5′ tetramethylbenzidene (TMB) were employed. An ordinary glass capillary was utilized as a bio-reactor where competitive assay took place. Standard HA was immobilized onto an unmodified glass capillary through simple physical adsorption. This glass capillary is much lower cost compared to a fused-silica capillary, and is well suited for use as part of the tubing of a flow system. Using the proposed system, the average amount of HA in human serums from patients with liver disease and healthy subjects could be differentiated with comparable efficiency as the conventional micro-plate assay (as compared by t-test), with an improved assay time per sample (20 min vs. 5 h), and with approximately 10 times less reagent consumption (10 − 80 μl vs. 100 − 350 μl).
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  • Masahiro YODOSHI, Tomoko IKUTA, Yukie MOURI, Shigeo SUZUKI
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 75-81
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Serotonin-bonded silica was developed for specific extraction of sialic-acid-containing glycans and glycopeptides. Serotonin, coupled by reductive amination with aldehyde silica particles via its ethylamino group, has strong affinity to sialic acid in glycan chain termini. Sialylated glycans trapped on serotonin silica particles are released by washing with ammonium acetate solution, providing highly efficient specific trap and release glycoconjugates. With >100 μmol/g adsorption capacity, the particles are applicable to purify labeled glycans after derivatization with 2-aminopyridine to remove excess reagents. Serotonin silica efficiently enriches sialic-acid-containing glycopeptides from tryptic digests for LC/MS analysis of glycans’ heterogeneity in glycoproteins.
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  • Malingappa PANDURANGAPPA, Devaramani SAMRAT
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 83-87
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A sensitive surfactant-mediated extractive spectrophotometric method has been developed, based on the reaction of ferric iron with sulfide to form ferrous iron and its subsequent reaction with ferricyanide to form Prussian Blue, to quantify trace levels of hydrogen sulfide/sulfide in environmental samples. The method obeys Beer’s law in the concentration range 2 − 10 μg of sulfide in 25 mL of aqueous phase with molar absorptivity (ε) of 3.92 × 104 L mol−1 cm−1. The colored species has been extracted into isoamyl acetate in the presence of a cationic surfactant i.e. cetylpyridinium chloride, to enhance the sensitivity of the method with ε value 5.2 × 104 L mol−1 cm−1. The relative standard deviation has been found to be 0.69% for 10 determinations at 4 μg of sulfide and the limit of detection was 0.009 μg mL−1. The interference from common anions and cations has been studied. The proposed method has been applied to the determination of residual hydrogen sulfide in the laboratory fume hood as well as ambient atmospheric hydrogen sulfide in the vicinity of open sewer lines after fixing the analyte in ionic form using suitable trapping medium.
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  • Abdolreza MIRMOHSENI, Ali OLAD
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 89-93
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A polystyrene coated quartz crystal nanobalance (QCN) sensor was developed for use in the determination of a number of linear short-chain aliphatic aldehyde and ketone vapors contained in air. The quartz crystal was modified by a thin-layer coating of a commercial grade general purpose polystyrene (GPPS) from Tabriz petrochemical company using a solution casting method. Determination was based on frequency shifts of the modified quartz crystal due to the adsorption of analytes at the surface of modified electrode in exposure to various concentrations of analytes. The frequency shift was found to have a linear relation to the concentration of analytes. Linear calibration curves were obtained for 7 − 70 mg l−1 of analytes with correlation coefficients in the range of 0.9935 − 0.9989 and sensitivity factors in the range of 2.07 − 6.74 Hz/mg l−1. A storage period of over three months showed no loss in the sensitivity and performance of the sensor.
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  • Shakuntala S. SAWANT
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 95-100
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Platinum(IV) can be determined spectrophotometrically with 5-chloro-2-hydroxythiobenzhydrazide on extraction into molten naphthalene from the aqueous phase with pH 2.2 − 6.0. Beer’s law is obeyed in the concentration range 1.0 − 7.0 μg cm−2 of Pt(IV) in 4-methyl-2-pentanone solution at 680 nm. The molar absorptivity and Sandell sensitivity are found to be 2.40 × 104 L mol−1 cm−1 and 8.0 ng cm−2, respectively. Six replicate analyses of a solution containing 40.0 μg of Pt(IV) gave a mean absorbance of 0.505 with a standard deviation of 0.0065 and a coefficient of variation of 1.30%. The complex is stable for more than 48 h. The metal to ligand ratio in the complex is determined to be 1:1. Interference from various ions is studied and the method is found to be selective for platinum. Platinum is determined in various synthetic mixtures and in some alloy samples. The method permits the sequential separation and determination of different amounts of platinum and rhenium from their mixtures.
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  • Abolfazl AGHANOURI, Seyed Hossein AMIRSHAHI, Farnaz AGAHIAN
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 101-105
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    The RGB values obtained from a digital camera were employed for reconstruction of spectral data of transparent colored solutions. A capturing box was assembled, and a spectral dataset gathered from colored solutions was used for this purpose. The matrix R method was employed to reconstruct the spectral transmission from RGB data. Two different light sources i.e. fluorescent and halogen lamps, were employed to achieve two sets of camera responses. The results of spectral transmission recovery confirmed the applicability of the matrix R method by the value of 3.24% as the average of root mean square percentage errors between the actual and reconstructed spectra. The reconstructed transmissions were converted to absorbance spectra, and the concentrations of colored solutions were simply estimated by Beer’s Law. The estimated concentrations were within the acceptable concentrations errors for some types of applications, such as estimating the amount of dyestuff in the dye solution.
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  • Mohammad Hossein ARBAB-ZAVAR, Mahmoud CHAMSAZ, Tahereh HEIDARI
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 107-110
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A simple method was developed for speciation and spectrophotometric determination of inorganic As(III) and As(V) using an electrochemical hydride generation technique. For speciation of As(III) and As(V), a graphite rod was used as cathode to reduce As(III) to AsH3, the rod was then replaced with a tin-lead alloy wire for reducing As(V) to AsH3. The spectrophotometric determination was based on the reaction of AsH3 with silver diethyldithiocarbamate to give an absorbing complex at 510 nm. Under the optimized conditions, the calibration curves were linear over the ranges of 0.1 − 5 μg ml−1 for As(III) and 0.5 − 4.0 μg ml−1 for As(V). The concentration detection limits of 0.02 and 0.06 μg ml−1 were achieved for As(III) and As(V), respectively. The relative standard deviations for five replicate speciation and determination of 3.0 μg ml−1 As(III) and As(V) were 0.8 and 7.2%, respectively. The accuracy and recovery of the method were evaluated by analyzing tap water spiked with As(III) and As(V).
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  • Javad ZOLGHARNEIN, Zhaleh ADHAMI, Ali SHAHMORADI, S. Norollah MOUSAVI
    Type: Original Papers
    2010 Volume 26 Issue 1 Pages 111-116
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    Platanus tree leaves were successfully used as a novel sorbent for removing of methylene blue (MB) dye from aqueous solutions. A 23 full factorial design was performed for screening of the main factors. The pH, initial concentration of dye (Cd) and amount of sorbent (m) were considered to be the three main factors at two different levels. It was found that all these factors and their interactions were significant at a certain confidence level (p < 0.05). Doehlert response surface design was applied (13 runs) for a further inspection of the main factors effect, which led to an empirical model. An analysis of the variances (ANOVA) and relevant tests, such as lack-of-fit and residual probability plot, confirmed the validity of the suggested model. A desirability function was used for the simultaneous optimization of both the removal efficiency (R%) and the maximum capacity of the sorbent (q). Plots of the response surface, through visualization of the suggested model, clearly showed the interactions between the main variables and their effects on the response.
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Notes
  • Ayfer CALISKAN, Hakan KARADENIZ, Asiye MERIC, Arzum ERDEM
    Type: Notes
    2010 Volume 26 Issue 1 Pages 117-120
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    The electrochemical aspects of interactions between DNA and two organic compounds are discussed herein. Potential DNA targeted compounds, 2-methyl-4-phenyl-benzo[4,5]imidazo[1,2-a]pyrimidine (C1) and 2,3,4-trimethyl-benzo[4,5]imidazo[1,2-a]pyrimidine (C2), were synthesized and their cytotoxic and/or growth inhibitory effects were studied previously. Disposable sensor technology was used to explore the interaction between the compounds and nucleic acid, such as fish sperm DNA at the electrode surface and in the solution phase. The changes upon encountering oxidation signals of electroactive DNA base-guanine and these compounds were monitored electrochemically.
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  • Matthieu TUBINO, Luís Francisco BIANCHESSI, Marta M. D. C. VILA
    Type: Notes
    2010 Volume 26 Issue 1 Pages 121-124
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A quantitative spot-test for the determination of metformin in pharmaceutical preparations using diffuse UV-visible reflectance is reported. The procedure is quite simple, involving in the formation of a metformin-nickel(II) complex on a glass filter membrane with a later measurement of the reflectance in the spectrophotometer using an integration sphere. The analytical results obtained with commercial products were statistically compared with those resulting from a method recommended by JP and by USP, where complete agreement was observed. The average RSD is 2.5% and the detection (0.009 mol L−1) and the quantitation (0.03 mol L−1) limits are quite adequate for pharmaceutical analysis.
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  • Huzhi ZHENG, Li LIU, Yihui LU, Yijuan LONG, Lingling WANG, Kam-Piu HO, ...
    Type: Notes
    2010 Volume 26 Issue 1 Pages 125-128
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A new luminescence-based toxicity test using luminous bacteria as a reporting agent has been developed to determine EC50 of different nanomaterials, such as gold nanoparticles and carbon nanotubes on living organisms. The whole assay takes only about 15 min and is as sensitive as other standard methods. Due to its technical simplicity, rapidity and sensitivity, this luminescent bacteria test has the potential to be developed as a general test of toxicity for a wide variety of nanomaterials.
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  • Myeounghee HYUN, Suhee CHOI, Jongwon KIM
    Type: Notes
    2010 Volume 26 Issue 1 Pages 129-132
    Published: January 10, 2010
    Released: January 10, 2010
    JOURNALS FREE ACCESS
    A simple strategy to fabricate porous three-dimensional gold-film electrodes using gold-coated microspheres (AuMS) is presented. The AuMS deposited on gold (AuMS/Au) are electrically interconnected, and show unique electrochemical properties indicating porous surface structures. The AuMS/Au electrodes exhibit electrocatalytic activities for oxygen reduction and peroxide oxidation, which indicates that the apparent macroporous structures also retain porous regions with nanometer-scale dimensions. The porous structures on AuMS/Au electrodes also provide a selective voltammetric response for glucose against ascorbic acid due to the different electron-transfer kinetics. Since AuMS/Au electrodes are simple to prepare compared with previously suggested systems, the present system could offer potential in electroanalytical applications as new gold-based substrates for further modifications of surfaces.
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