著者
Tomoya SUZUKI Takeshi OGATA Mikiya TANAKA Tohru KOBAYASHI Hideaki SHIWAKU Tsuyoshi YAITA Hirokazu NARITA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.12, pp.1353-1360, 2019-12-10 (Released:2019-12-10)
参考文献数
17
被引用文献数
4

The effective recovery of Rh(III) from mixtures also containing Pd(II) and Pt(IV) is one of the most difficult tasks in platinum group metal refining. Adding 3,3′-diaminobenzidine (DAB) to 7 and 10 M HCl aqueous solutions containing Rh(III), Pd(II), and Pt(IV) chlorido species affords the effective separation of Rh(III) from Pd(II) and Pt(IV) through a process where Rh(III) becomes sequestered into solid phases composed of DAB. The stoichiometry and inner coordination sphere of the metal in Rh–DAB complexes were determined by estimating the Rh(III), H+, and Cl− concentrations in the solid phase and X-ray absorption fine structure measurements to clarify the mechanism of DAB selectivity for Rh(III). These results indicate that the Rh–DAB reaction in a concentrated HCl solution occurs in two steps: (1) the precipitation of DAB trihydrochloride salts, where DAB’s amino groups are protonated and (2) anion exchange of the trihydrochloride salts for chloride ions with [RhCl6]3−, which is the predominant species in a concentrated HCl solution. By contrast, ion-pair complexes with [PdCl4]2− and [PtCl6]2− were not observed in DAB phases. The significantly lower affinity of the DAB trihydro cation for [PtCl6]2− and [PdCl4]2− than for [RhCl6]3− in 7 and 10 M HCl solutions accounts for the effective separation of Rh(III) from Pd(II) and Pt(IV).
著者
Miki ISODA Makoto FUKUMA Akira HARATA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.12, pp.1311-1315, 2019-12-10 (Released:2019-12-10)
参考文献数
22
被引用文献数
3

The first demonstration of a photothermal heterodyne interferometer (PHI) combined with micro-HPLC (high-performance liquid chromatography) is reported. A semiconductor laser (375 nm) was used for excitation, and the temperature change caused by heat released from photoexcited species was detected with a He–Ne laser (632.8 nm). The temperature-dependent refractive index change of the solvent modified the optical path of the probe beam. The phase difference between two arms of the interferometer, one passing through the heated sample and another as a reference, was sensitively detected with the PHI. The nitro-polycyclic aromatic hydrocarbon and vitamin mixture separated via micro-HPLC was successfully detected with the PHI as well as a UV detector. The detection limit of the PHI for riboflavin in the absorbance units was 77 times better than that of the commercial UV detector. The detection limit of the PHI with a small flow cell (6 nL) was the same as that with a large flow cell (18 nL) for 1-nitropyrene.
著者
Junho LEE Ji Won HA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.11, pp.1237-1241, 2019-11-10 (Released:2019-11-10)
参考文献数
42
被引用文献数
2

Questions surrounding the optical properties of two-dimensional (2D) triangular single gold nanoplates (AuNPs) remain largely unanswered. Herein, a scanning-electron microscopy-correlated single-particle study was conducted to identify polarization-dependent optical properties of AuNPs under dark-field (DF) and differential interference contrast (DIC) microscopy. AuNPs with an aspect ratio of ∼3 showed a single broad DF scattering spectrum without separation of the two dipole and quadrupole resonance modes present in 2D AuNPs. Polarization-sensitive interference properties of the individual AuNPs were revealed through periodic changes in the intensities and types of DIC images obtained. A dipole resonance mode was found to mainly contribute to the polarization-sensitive interference properties of AuNPs. Furthermore, DIC polarization anisotropy allowed us to track the real-time orientation of a dipole resonance mode of a AuNP rotating on a live cell membrane.
著者
Young-Jin KIM Kazuo HOSOKAWA Mizuo MAEDA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.11, pp.1227-1236, 2019-11-10 (Released:2019-11-10)
参考文献数
40
被引用文献数
11

We present a microRNA (miRNA) detection method that achieves enhanced sensitivity by means of a power-free microfluidic chip without the requirement of an external power source. The miRNA detection is completed by sandwich hybridization between probe DNAs and target miRNA with small sample volume (0.5 μL) within 20 min. Fluorescence signals after hybridization were amplified by laminar flow-assisted dendritic amplification (LFDA) using fluorescein isothiocyanate (FITC)-labeled streptavidin (F-SA) and biotinylated anti-streptavidin (B-anti-SA) as amplification reagents. To enhance the sensitivity of on-chip miRNA detection, the hybridization buffer solution was newly optimized with three main components—sodium dodecyl sulfate (SDS), formamide and dextran sulfate—that are known to strongly influence hybridization. An on-chip miRNA detection test in the newly optimized hybridization buffer (0.2% SDS, 5% formamide and 1% dextran sulfate) revealed dramatic increases in both the LFDA signal in the sample channel and the signal-to-background ratio (S/B ratio). Moreover, the LFDA signals in a blank reference channel remained low due to the suppression of non-specific bindings and hybridizations. By changing the hybridization buffer, we obtained an improved limit of detection (LOD) that was 0.045 pM (miRNA-196a) and 0.45 pM (miRNA-331), which are around 30- and 10-fold better than that of when control hybridization buffer was used. The improved performance of our miRNA detection system with short running time and high sensitivity could contribute to future research, including point-of-care diagnostic systems.
著者
Toshinori MORISAKU Hitomi ONUKI Kenji HASHIMOTO Kazuyuki KUCHITSU Hiroharu YUI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.11, pp.1203-1207, 2019-11-10 (Released:2019-11-10)
参考文献数
21
被引用文献数
2

A near-infrared laser-induced surface deformation (NIR-LISD) microscope is developed and is applied to the dynamic viscoelastic measurements of the surface of a living plant cell. In the microscope, the deformation of the surface is induced by an NIR laser beam, and then the change in intensity of the probe beam reflected from the surface reflects its viscoelasticity. The application of the NIR laser beam has a great advantage for the prevention of damage to the plant cell compared to the irradiation of a visible laser beam in LISD measurements. The NIR-LISD microscope allows for discriminating the differences in power spectra between the subapical and lateral regions of single rhizoids. It is a useful method for the dynamic viscoelastic measurements of cells, such as plant cells, that are damaged due to the strong absorption of ultraviolet or visible light.
著者
Sakura YOSHII Masanobu MORI Daisuke KOZAKI Takayuki HOSOKAWA Hideyuki ITABASHI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.10, pp.1117-1122, 2019-10-10 (Released:2019-10-10)
参考文献数
35
被引用文献数
4

This study demonstrated that a guard column containing anion-exchange resin has the potential for use as a separation column for acid eluent. Specifically, a 1-cm long anion-exchange guard column with a 4.6-mm internal diameter provided good separation of monovalent inorganic anions, by elution of 8 mM tartaric acid or 4 mM malic acid. Using the guard column with acid eluent could be applied to evaluation of nitrite and nitrate ions in mountain and urban river water samples. When the guard column was connected in front of a cation-exchange separation column (15 cm long × 4.6 mm internal diameter) in a series, the system provided simultaneous separation of anions and cations in eluent of 8 mM tartaric acid and 0.5 mM 18-crown-6 ether by a single injection.
著者
Hidenobu NAKAO Je-Deok KIM
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.10, pp.1065-1067, 2019-10-10 (Released:2019-10-10)
参考文献数
11
被引用文献数
3

We have reported a simple method for separating lactic acid bacteria (LAB) from yogurt. This method is based on the process of destructions and denaturation of casein micelle aggregates by vortexing, and can supply samples containing only LAB. Recovered LAB were clearly observable by microscopy, meaning that morphological changes could be directly detected at the single-cell level. This method will be a helpful tool for the analyzing various LAB, including their enzyme activity and protein expression.
著者
Kojiro SHIMOJO Noboru AOYAGI Takumi SAITO Hiroyuki OKAMURA Fukiko KUBOTA Masahiro GOTO Hirochika NAGANAWA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.30, no.2, pp.263-269, 2014-02-10 (Released:2014-02-10)
参考文献数
39
被引用文献数
23 51

Liquid–liquid extraction of lanthanide ions (Ln3+) using N,N-dioctyldiglycolamic acid (DODGAA) was comprehensively investigated, together with fluorescence spectroscopic characterization of the resulting extracted complexes in the organic phase. DODGAA enables the quantitative partitioning of all Ln3+ ions from moderately acidic solutions, while showing selectivity for heavier lanthanides, and provides remarkably high extraction separation performance for Ln3+ compared with typical carboxylic acid extractants. Furthermore, the mutual separation abilities of DODGAA for light lanthanides are higher than those of organophosphorus extractants. Slope analysis, loading tests, and electrospray ionization mass spectrometry measurements demonstrated that the transfer of Ln3+ with DODGAA proceeded through a proton-exchange reaction, forming a 1:3 complex, Ln(DODGAA)3. The stripping of Ln3+ from the extracting phase was successfully achieved under acidic conditions. Time-resolved laser-induced fluorescence spectroscopy revealed that the extracted Eu3+ ions were completely dehydrated by complexation with DODGAA.
著者
Chuichi HIRAYAMA Masayo SAKATA Hirotaka IHARA Kunio OHKUMA Makoto IWATSUKI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.8, no.6, pp.805-810, 1992-12-10 (Released:2006-06-30)
参考文献数
16
被引用文献数
13 13

A novel adsorbent for the selective removal of endotoxin from various protein solutions has been prepared. The adsorbent comprises aminated poly(γ-methyl L-glutamate) (PMLG) spheres. The larger is the number of incorporated amino groups, the larger is the endotoxin-adsorption capacity of the adsorbent, the smaller is the pore size (exclusion of molecular weight; Mlim) of the adsorbents, the smaller is the number of various proteins adsorbed. When Mlim was smaller than 300 (as the molecular weight of polysaccharide) and the amino-group content was 3.2meq/g, the adsorbent selectively removed endotoxin from various endotoxin-containing samples, such as protein solutions, without affecting the effective substances, even at such a high ionic strength (μ) of 0.2-0.4. Consequently, aminated PMLG spheres with a certain pore size are considered to be a useful adsorbent for the removal of endotoxin from drugs and fluids for injection.
著者
Hsuan CHUNG Satoshi TAJIRI Mai HYOGUCHI Riho KOYANAGI Akihiro SHIMURA Fuyuko TAKATA Shinya DOHGU Toshiro MATSUI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.4, pp.433-439, 2019-04-10 (Released:2019-04-10)
参考文献数
23
被引用文献数
12

In this study, a simultaneous assay for catecholamines and their metabolites in the brain was established using liquid chromatography–mass spectrometry (LC-MS). To achieve complete separation, a cation-exchange/reversed-phase mixed-mode copolymer resin column containing 0.81 wt% sulfo groups was used for the simultaneous LC-MS assay. The analyzed catecholamines were dopamine (DA), norepinephrine (NE), and epinephrine (E), while the metabolites lacking amino groups were 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG). The metabolites were separated and detected using LC-MS, on columns with and without sulfo groups. However, we could not achieve adequate separation of catecholamines on both columns using a gradient elution of 0 – 50 (v/v)% methanol containing 0.1 (v/v)% formic acid (FA). When volatile ion-pairing reagents were added to the mobile phase, they improved the retention and detection of catecholamines on the sulfonated mixed-mode column. Under optimized elution conditions, which involved a linear gradient elution of water containing 0.1 (v/v)% FA to 50 (v/v)% acetonitrile in 50 mM ammonium formate at 40°C and a 0.20 mL/min rate, all six target molecules were simultaneously detected within 25 min, when using negative mode LC-MS on a sulfonated mixed-mode column. The limits of detection (LODs) for DA, NE, E, DOPCA, HVA, and MHPG were determined to be 20.7, 12.6, 74.6, 1110, 18.7, and 3196 nM, respectively. Moreover, the established LC-MS assay allowed the detection of endogenous DA, NE, and HVA, in normal mouse brain samples at concentrations higher than 20, 9, and 4 pmol/mg, respectively.
著者
Yukiko HORIE Ayaka GOTO Sumi TSUBUKU Mari ITOH Shigeo IKEGAWA Shoujiro OGAWA Tatsuya HIGASHI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.4, pp.427-432, 2019-04-10 (Released:2019-04-10)
参考文献数
30
被引用文献数
12

Many studies have demonstrated that the dietary supplementation of polyamines, especially spermidine (SPD), prevents age-related diseases. Rice bran is rich in polyamines and their amounts could be increased by fermentation with Aspergillus oryzae (A. oryzae). In this study, we developed a method for the determination of putrescine (PUT), SPD and spermine (SPM) in rice bran samples by liquid chromatography/electrospray ionization–tandem mass spectrometry (LC/ESI-MS/MS) after derivatization with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F). The derivatization improved the LC retention and ESI-MS/MS detectability of the polyamines, and consequently enabled precise and accurate quantification. Using this method, we found that the SPD content increased to 158% due to fermentation with A. oryzae, while the content of PUT and SPM decreased. SPD is known as the polyamine playing a central role in cell proliferation and growth, and therefore has health benefits. The fermented rice bran might be a good material for functional foods aimed at SPD supplementation.