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Volume 66, Issue 12
Special Articles: Modern Analytical Chemistry Integrated with Different Fields
Displaying 1-6 of 6 articles from this issue
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Research Papers
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Yuhei YAMAMOTO, Fumiya KITA, Narumi ISONO, Shoji IMAIArticle type: Research Papers
2017 Volume 66 Issue 12 Pages 875-883
Published: December 05, 2017
Released on J-STAGE: January 11, 2018
JOURNAL FREE ACCESSThe apparent and intrinsic stability constants (log β and log KMA) of metal ions (Be2+, Ni2+, Co2+, Cd2+, Pb2+) and humic acid under Fe3+ ion competition were determined on using an ultrafiltration method. For Ni2+ and Cd2+ ions, log β decreased with an increase of the Fe3+ ion loading level, suggesting that the complexation of Ni2+ and Cd2+ ions with humic acid can be blocked by Fe3+ ion. Log β of Co2+ ion slightly decreased with an increase of the Fe3+ ion loading level, suggesting that the impact of the Fe3+ ion competition on Co2+ ion was limited. Log β of Be2+ and Pb2+ ions with AHA was almost constant with an increase of the Fe3+ ion loading level, suggesting that the binding sites of Be2+ and Pb2+ ions in AHA were different from that of Fe3+ ion. Based on log KMA obtained from a complexation equilibrium model, the amount of metal-AHA complexes was calculated under Fe3+ ion competition. The calculated values were larger than the experimental values, suggesting that the calculated values overestimated the impact of Fe3+ ion competition.View full abstractDownload PDF (1059K) -
Shota AIDA, Yuki TAKIMOTO, Takuto SAKUMURA, Kazuyuki MATSUSHITA, Takas ...Article type: Research Papers
2017 Volume 66 Issue 12 Pages 885-892
Published: December 05, 2017
Released on J-STAGE: January 11, 2018
JOURNAL FREE ACCESSA wavelength-dispersive X-ray fluorescence (WD-XRF) imaging spectrometer gives XRF images more rapidly than energy-dispersive X-ray fluorescence (ED-XRF). The analyzing area by this method is dependent on the diameter of the used 2D collimator. We considered large-area imaging while scanning a sample, to enlarge the analyzing area. Then, the analyzing object was measured at each segment, and obtained XRF images were combined. As the result, Cu and Br elemental whole images were constructed for an electronic circuit card (30 mm × 54 mm), with a total exposure time of 54 s. In addition, WD-XRF imaging rapidly provides specific elemental images. Therefore, this method was applied for the monitoring of chemical reactions in liquid samples. WD-XRF imaging was repeated in an exposure time of 60 s/frame for observing the dissolution process of metals in solutions. Consequently, the dissolution process of a Zn piece in hydrochloric acid was visualized from Zn Kα intensity distributions.View full abstractDownload PDF (1352K) -
Daichi SUZUKI, Yukio KAWANOArticle type: Research Papers
2017 Volume 66 Issue 12 Pages 893-899
Published: December 05, 2017
Released on J-STAGE: January 11, 2018
JOURNAL FREE ACCESSThe development of non-destructive quality inspection methods has been increasingly attracting much attention to ensure the reliability and safety of products, especially in the fields of medicine and materials engineering. In this work, we used terahertz (THz) imaging and spectroscopy as a novel analysis method for in-process quality inspections of medical drugs and polymers. By utilizing advantageous features of THz waves, such as relatively high transmission through objects and THz fingerprint spectra of polymers, we demonstrated non-destructive and non-contact quality inspections, such as the identification of mixtures of medical drugs, the detection of cracks and organic/inorganic contaminations inside multi-layer polymer films, and the evaluation of polymer film thickness. These results indicate that the inspection method based on THz technology can be powerfully used as a quality assurance system.View full abstractDownload PDF (1088K) -
Masaki YAMANASHI, Aoi YAMAUCHI, Kouichi TSUJIArticle type: Research Papers
2017 Volume 66 Issue 12 Pages 901-907
Published: December 05, 2017
Released on J-STAGE: January 11, 2018
JOURNAL FREE ACCESSA full-field energy-dispersive X-ray imaging apparatus (FF-EDXRF) using a photon-counting technique was produced, and its performance was confirmed. The energy resolution and the spatial resolution at 2 bin for Fe Kα were 142 eV and 52 μm, which results were comparable to the energy-dispersive X-ray detector and micro-XRF imaging apparatus, respectively. X-ray fluorescence images of multi elements were obtained at the same time for a print circuit board sample. However, the quantification of XRF imaging measured by FF-EDXRF has not been established. The application of a unified calibration curve for all pixels, which was estimated by Ni standard materials (FXS 326 – 331) and evaluated by the R2 value, has permitted these quantitative XRF measurements. The accuracy of the calibration curve and the R2 value was satisfied, and one calibration curve created by summarizing all of the calibration curve are applied for all effective pixels.View full abstractDownload PDF (1023K)
Technical Papers
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Noriaki NISHIDA, Yasuko KOKAJI, Sachio YAMAMOTO, Mitsuhiro KINOSHITA, ...Article type: Technical Papers
2017 Volume 66 Issue 12 Pages 909-917
Published: December 05, 2017
Released on J-STAGE: January 11, 2018
JOURNAL FREE ACCESSCompared to N-linked oligosaccharides, O-linked oligosaccharides were rarely reported for their analysis due to the absence of glycanases having wide substrate specificity to release all O-linked oligosaccharides. Therefore, O-linked oligosaccharides have often been released by chemical methods, such as hydrazinolysis and β-elimination under alkaline conditions, but the liberated oligosaccharides released by these methods are susceptible to alkaline conditions which cause epimerization and degradation, called peeling reaction and the hydrolysis of N-acetyl groups. To compare the releasing efficiency and the degradation rate of previously reported releasing methods, we developed a novel HPLC method for the analysis of O-linked oligosaccharides: oligosaccharides released from glycoproteins are labeled quantitatively with 7-amino-4-methylcoumarin (AMC) and separated by reversed-phase HPLC, and then fluorimetrically detected with high sensitivity. In the releasing methods, we found that 25 % ammonia is most optimal, and can be applied to the release of N-linked oligosaccharides. We established a method that could be applied to the rapid and simple and nonspecific release of N-linked oligosaccharides. Various AMC-labeled N-linked oligosaccharides released from glycoproteins were used as samples, and were separated by reversed-phase HPLC and fluorimetrically detected with high sensitivity for comparing with the enzymatic releasing method using PNGase F.View full abstractDownload PDF (1618K)
Notes
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Takao FUKUOKA, Akinobu YAMAGUCHI, Yuichi UTSUMI, Ryosuke KURAMOTO, Yas ...Article type: Notes
2017 Volume 66 Issue 12 Pages 919-923
Published: December 05, 2017
Released on J-STAGE: January 11, 2018
JOURNAL FREE ACCESSThe coming era of a "Trillion Sensors Universe" or "Nanosensors and the Internet of Nanothings" requires countless tiny sensor devices. Since surface enhanced Raman scattering (SERS) produces strong signals efficiently in such a tiny region of noble metal nanostructures with corresponding localized plasmon resonance, a SERS active nanostructure is promising to realize nanosensor devices. As for the costless fabrication of trillion SERS active nanostructures, the bottom-up process of self-assembled gold nanoparticles (AuNP) is desirable. The self-assembling of colloidal AuNP (40 nm) was carried out under time-controlled agitation for 1 s, 5 s, 30 s and 60 s at 500 rpm. A series of absorption spectra of these AuNP dispersions showed snapshots of the proceeding aggregation. The wavelength at the absorption maximum of AuNP dispersion under continuos agitation shifted from 425 nm to 680, 750, 870 nm and almost vanished in the visible region at 60 s. Interestingly, these aggregation dispersions were quasi-stable enough to take 785 nm SERS measurements while agitation was stopped. Comparisons between absorption the spectra and the SERS intensity strongly suggested the intensity of localized plasmon resonance both at the incident laser wavelength and at the Raman wavelength correlative to SERS intensity for the certain stages of self-assembling. We believe that these results are typical demonstrations in collective systems of colloidal AuNP assembles that support the electromagnetic mechanism of SERS. Consequently, SERS active nanostructures for nanosensors and nanobeacons were sufficiently fabricated by the bottom-up process of the diffusion-limited aggregation of colloidal AuNP under a shear force of time-controlled agitation.View full abstractDownload PDF (893K)
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