著者
Akihiko ISHIDA Mitsutaka FUJII Takehiro FUJIMOTO Shunsuke SASAKI Ichiro YANAGISAWA Hirofumi TANI Manabu TOKESHI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.31, no.11, pp.1163-1169, 2015-11-10 (Released:2015-11-10)
参考文献数
33
被引用文献数
25 27

A compact and lightweight liquid chromatography system is presented with overall dimensions of 26 cm width × 18 cm length × 21 cm height and weight of 2 kg. This system comprises a battery-operated compact electroosmotic pump, a manual injector, a microfluidic chip device containing a packed column and an electrochemical detector, and a USB bus-powered potentiostat. The pumping system was designed for microfluidic-based reversed-phase liquid chromatography in which an electroosmotically generated water stream pushes the mobile phase via a diaphragm for the output. The flow rate ranged from 0 to 10 μL/min and had a high degree of precision. The pumping system operated continuously for over 24 h with dry batteries. The column formed in the microfluidic device was packed with 3-μm ODS particles with a length of 30 mm and a diameter of 0.8 mm. The results presented herein demonstrate the performance of the pumping system and the column using alkylphenols, catecholamine, catechin, and amino acids.
著者
Nobutoshi OTA Genki N. KANDA Hiroyuki MORIGUCHI Yusufu AISHAN Yigang SHEN Rikuhiro G. YAMADA Hiroki R. UEDA Yo TANAKA
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.1141-1147, 2019-10-10 (Released:2019-10-10)
参考文献数
24
被引用文献数
5

Microfluidic devices are important platforms to culture and observe biological tissues. Compared with conventional setups, microfluidic devices have advantages in perfusion, including an enhanced delivery of nutrients and gases to tissues. However, explanted tissues can maintain their functions for only hours to days in microfluidic devices, although their observations are desired for weeks. The suprachiasmatic nucleus (SCN) is a brain region composed of heterogeneous cells to control the biological clock system through synchronizing individual cells in this region. The synchronized and complicated cell–cell interactions of SCN cells are difficult to reproduce from seeded cells. Thus, the viability of explanted SCN contributes to the study of SCN functions. In this paper, we propose a new perfusion platform combining a PDMS microfluidic device with a porous membrane to culture an explanted SCN for 25 days. We expect that this platform will provide a universal interface for microfluidic manipulation of tissue explants.
著者
Seitaro OHTSU Masamitsu YAMAGUCHI Hisashi NISHIWAKI Eiichiro FUKUSAKI Shuichi SHIMMA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.34, no.9, pp.991-996, 2018-09-10 (Released:2018-09-10)
参考文献数
19
被引用文献数
10

Imidacloprid is widely used for exterminating harmful insects; however, information regarding its distribution in insects is limited. Herein, we developed a visualization method for imidacloprid in Drosophila melanogaster, by using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS). IMS requires sample cryosections; however, certain challenges prevail in retaining fly morphology in sections owing to their small size and heterogeneous components. Therefore, the section preparation method was optimized first, followed by imidacloprid distribution visualized using MALDI-IMS. Using 10% gelatin as an embedding material and 70% ethanol for pretreatment, the gaps between embedding material and D. melanogaster body surface were reduced. The tight adhesion between embedding media and D. melanogaster retains fly morphology in sections. Furthermore, the imidacloprid standard was analyzed separately via MALDI and electrospray ionization (ESI), and imidacloprid was converted to guanidine-imidacloprid via laser irradiation. Consequently, the imidacloprid distribution in D. melanogaster was successfully visualized using guanidine-imidacloprid as the target peak.
著者
Misaki HATA Masato SUZUKI Tomoyuki YASUKAWA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.37, no.6, pp.803-806, 2021-06-10 (Released:2021-06-10)
参考文献数
32
被引用文献数
3

We proposed selective manipulation techniques for retrieving and retaining target cells arrayed in microwells based on dielectrophoresis (DEP). The upper substrate with microband electrodes was mounted on the lower substrate with microwells based on the same design of microband electrodes by 90 degree relative to the lower substrate. A repulsive force of negative dielectrophoresis (n-DEP) was employed to retrieve the target cells from the microwell array selectively. Furthermore, the target cells were retained in the microwells after other cells were removed by n-DEP. Thus, the system described in this study could make it possible to retrieve and recover single target cells from a microwell array after determining the function of cells trapped in each microwell.
著者
Yuki HIRAKAWA Tomomi YAMASAKI Ayako HARADA Seiji IWASA Hiroshi NARITA Shiro MIYAKE
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.34, no.5, pp.533-539, 2018-05-10 (Released:2018-05-10)
参考文献数
30
被引用文献数
15

A simultaneous immunosensor based on surface plasmon resonance (SPR) was developed for determination of 3 pesticides —boscalid, clothianidin and nitenpyram— instead of the direct competitive enzyme-linked immunosorbent assays (dcELISAs) widely used as individual determination methods. Carboxy groups that introduced compounds to their pesticides were designed, and conjugates of them and bovine serum albumin were immobilized onto separate channels of the same sensor chip. When a mixture of 3 monoclonal antibodies reacted to each pesticide, and 3 pesticides were injected into the SPR immunosensor, each channel showed specific reactivity at 15 – 93 ng mL−1 for boscalid, 6.7 – 27 ng mL−1 for clothianidin, and 7.3 – 62 ng mL−1 for nitenpyram. Recovery tests using vegetables spiked with a mixture of 3 pesticides showed good results: 75 – 90%, 88 – 104%, and 72 – 105%, respectively, with a high correlation to results of the dcELISAs. The SPR immunosensor would be useful for the determination of pesticide residues in vegetables.
著者
金 景勲 片山 佐一
出版者
The Japan Society for Analytical Chemistry
雑誌
分析化学 (ISSN:05251931)
巻号頁・発行日
vol.20, no.1, pp.29-36, 1971

(Bi<SUB>1-<I>x</I></SUB>Sb<SUB><I>x</I></SUB>)<SUB>2</SUB>(Te<SUB>1-<I>y</I></SUB>Se<SUB><I>y</I></SUB>)<SUB>3</SUB> 系において,重量パーセントでビスマス(0~63.46),アンチモン(0~50.33),テルル(0~61.47),セレン(0~49.67)をそれぞれの広い組成の範囲内において,けい光X線による非破壊定量分析を行なった.分析に用いたけい光X線は,BiL<SUB>α</SUB>,L<SUB>β</SUB>;SbK<SUB>α</SUB>,K<SUB>β</SUB>;TeK<SUB>α</SUB>,K<SUB>β</SUB>;SeK<SUB>α</SUB>,K<SUB>β</SUB>である.ビスマステルライドを基盤にし,ビスマスの代わりにアンチモン,テルルの代わりにセレンをそれぞれ原子比で20(%)刻みに置きかえた36種の標準試料を作り,まず係数αを定め,それを用い各元素のけい光X線の相対強度と元素の重量パーセントとの関係を示す連立方程式を解き重量パーセントを求めた.解析はK<SUB>α</SUB>,L<SUB>α</SUB>線とK<SUB>β</SUB>,L<SUB>β</SUB>線について.それぞれ別に用いた.その結果は次のとおりである.K<SUB>α</SUB>とL<SUB>α</SUB>線のけい光X線を用いた際の誤差と変動率はそれぞれ±1.15%と±4.3%である.同様に,K<SUB>β</SUB>とL<SUB>β</SUB>線については±0.9%と±3.7%である.
著者
Suchada CHUANUWATANAKUL Orawon CHAILAPAKUL Shoji MOTOMIZU
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.24, no.4, pp.493-498, 2008 (Released:2008-04-10)
参考文献数
40
被引用文献数
36 38

The electrochemical properties of chloramphenicol at a boron-doped diamond thin-film (BDD) electrode were studied using cyclic voltammetry. The highest current response of chloramphenicol was obtained with phosphate buffer, pH 6 (0.1 M) in 1% ethanol. The relationship between the concentration of chloramphenicol and the current response was linear over the range of 0.1 - 10 mM (R2 = 0.9990). The amount of chloramphenicol was analyzed by flow-injection analysis. A thin-layer flow cell equipped with a BDD electrode was used as an amperometric detector, and experiments were carried out at -0.7 V (vs. Ag/AgCl). The linear relationship between the current response and the concentration of chloramphenicol in the range of 0.1 - 50 µM (R2 = 0.9948) and the limit of detection of 0.03 µM (S/N = 3) were obtained. This method has been successfully applied to the determination of chloramphenicol in sterile eye drops and milk sample by the standard addition method. The average recoveries of chloramphenicol in eye drops were 98.0%, and the average recoveries of chloramphenicol from spiked milk were 93.9 - 103%.
著者
片岡 由行 河野 久征 河原 直樹 越智 寛友 西埜 誠 中村 秀樹
出版者
The Japan Society for Analytical Chemistry
雑誌
分析化学 (ISSN:05251931)
巻号頁・発行日
vol.69, no.7.8, pp.363-371, 2020-07-05 (Released:2020-11-07)
参考文献数
24
被引用文献数
1

蛍光X線分析におけるファンダメンタルパラメータ法(FP法)は,理論的に蛍光X線強度を計算して定量分析に利用する方法である.FP法を搭載した波長分散型蛍光X線分析装置は,1980年代後半に国内X線機器メーカーであるリガクと島津製作所が世界に先駆けて開発し,エネルギー分散型装置への適用を含め機能拡張と改良を重ね,その応用範囲も拡大し一般的に使用されるようになった.FP法の代表的な応用例として標準試料を必要としないスタンダードレス分析があるが,電子材料やめっき分析に使用される薄膜FP法,また,従来の検量線法におけるマトリックス補正係数に,FP法を利用して求めた係数を使用する方法も,各種材料のJISやISOの分析規格として採用されている.また,蛍光X線に加え,散乱線強度を含めたFP法も開発し,ポリマーや生体試料の分析や不定形試料の分析にも応用されており,著者らが開発したFP法は,蛍光X線分析の応用範囲の拡大に大きく貢献することができたと考えている.
著者
Yingying ZHANG Luhui WANG Yafei DONG
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.2, pp.181-187, 2019-02-10 (Released:2019-02-10)
参考文献数
32
被引用文献数
3 4

Due to structual polymorphism, excellent binding activity and functional significances in biological regulation, G-quadruplex has become the focus of research as an innovated module for analytical chemistry and biomedicine. Meanwhile, in the biosensor fields, new nanomaterial graphene oxide (GO) has also received extensive attention due to its brilliant physical and chemical properties. Herein, we propose a non-label and enzyme-free logic operation platform based on G-quadruplex structure and GO instead of any expensive modification. Taking advantage of the quenching ability of GO to AgNCs and the fluorescence enhancement of NMM (N-methylmesoporphyrin IX) mediated by the split G-quadruplex, a series of binary logic gates (AND, OR, INHIBIT, XOR) have been constructed and verified by biological experiments. Subsequently, two combinatorial logic gates were successfully realized conceptually on the basis of the same BGG platform, including half adder and half subtractor. Taken together, such a universal platform has great potential in applications, such as biocomputing, bio-imaging and disease diagnosis, which cultivate a new view for future biological research.
著者
豊島 学 蒋 緒光 小川 覚之 廣川 信隆 吉川 武男
出版者
The Japan Society for Analytical Chemistry
雑誌
分析化学 (ISSN:05251931)
巻号頁・発行日
vol.69, no.10.11, pp.531-537, 2020-10-05 (Released:2020-10-17)
参考文献数
46

統合失調症は約100人に1人が発症する比較的頻度の高い精神疾患である.幻覚・妄想などの特徴的な症状に加えて,意欲が低下し感情が鈍麻する,認知機能が障害されるなどの症状があり,社会生活に支障が出ることが多い.統合失調症の病因・病態には,複数の遺伝的要因と環境要因の関与が考えられているが,分子メカニズムにはいまだ不明な部分が多い.近年,統合失調症の病因・病態に酸化ストレス(カルボニルストレス)や小胞体ストレスの関与が示唆さており,それらストレスによるタンパク質の「質」の低下(凝集化などによる機能低下)が注目されようになった.本稿では,統合失調症の基礎知識から研究方法について紹介したのち,細胞内ストレスに注目して,統合失調症で見られるタンパク質の「質」の変化について概説する.
著者
菊田 真也 山上 基行 河野 浩 堂井 真
出版者
The Japan Society for Analytical Chemistry
雑誌
分析化学 (ISSN:05251931)
巻号頁・発行日
vol.69, no.9, pp.463-470, 2020-09-05 (Released:2020-11-11)
参考文献数
11

全反射蛍光X線(TXRF)分析はX線を極めて低角度で試料に入射させることで試料表面の微量元素を高感度に分析する手法である.TXRFは半導体製造工程管理に広く用いられており,Siウェーハ上の汚染評価を行うことができる.半導体デバイスの微細化,高性能化の要求から半導体製造工程は年々複雑になっており,汚染評価の重要性が高まるのに伴い,TXRF測定装置の高感度化,高機能化に向けた装置開発を行っている.本稿では,データ分析の観点からTXRF分析に機械学習を応用した取り組みについて紹介する.TXRF測定で得られた約9000個のデータを教師データとして,畳み込み層が1層,隠れ層が4層のニューラルネットワークモデルに投入し,波形プロファイルと含まれる元素,含有量の関係を学習させた.その後,波形プロファイルのみを投入することで含まれる元素と含有量を推定させた.その結果,短時間測定において従来のピークフィットによる手法では見逃していた元素を検出することができ,長時間測定と同等の結果が得られた.本稿ではTXRFにおける機械学習による高感度化の可能性について論じた.
著者
Momona HORIGUCHI Shinsuke KUNIMURA
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.36, no.11, pp.1311-1315, 2020-11-10 (Released:2020-11-10)
参考文献数
14
被引用文献数
3

This paper describes a method for obtaining information that can contribute to individual identification from a single hair colored with a hair dye product using a combination of surface-enhanced Raman scattering (SERS) and X-ray fluorescence (XRF) analyses. SERS and XRF spectra of single hog hairs colored with several commercially available hair dye products were measured. SERS spectral patterns tended to be different depending on the hair dye products used for hair coloring. However, SERS spectral patterns of single hog hairs colored with different hair dye products that would produce similar types of dyes were similar. By performing XRF analysis, characteristic metallic elements originating from some hair dye products were detected. Therefore, XRF can contribute to identifying the difference among colored hairs that cannot be identified only by SERS. SERS and XRF analyses of a single shed hair can contribute to individual identification used in forensic science.
著者
八井田 朱音 大塚 理子 山田 安咲紀 中野 和彦 松井 久美 関本 征史 稲葉 一穂 伊藤 彰英
出版者
The Japan Society for Analytical Chemistry
雑誌
分析化学 (ISSN:05251931)
巻号頁・発行日
vol.69, no.7.8, pp.341-350, 2020-07-05 (Released:2020-11-07)
参考文献数
25
被引用文献数
1

キレート固相抽出法を併用するICP-MS法により,多摩川の中流域から河口域までの15地点で採水した河川水試料を分析し,Sc,Y及びPmを除く14元素の希土類元素を定量した.分析結果をPAAS(Post-Archean Australian Average Shale)で規格化して希土類元素存在度パターン(希土パターン)を作成して考察したところ,多摩川では中流域の下水処理放流水合流地点から河口域までの試料で,Gdの存在度が隣接する他の希土類元素よりも明らかに高いGdの濃度異常が定常的に確認された.この濃度異常は,MRI造影剤として人体に投与されたGd化合物により引き起こされることが確認されており,Gd濃度を約20〜25年前の文献値と比べると,中流域と河口域の2地点について,それぞれ2〜4倍,3〜4倍の濃度であった.したがって近年,多摩川河川水においてはGd濃度が上昇していることが明らかになった.さらに,Gdの濃度異常について国内外の他の文献値と比較するために,Gdの濃度異常をGd異常度として数値化し,多摩川の潜在的人為汚染の現状を評価した.その結果,本研究で分析した多摩川中流域河川水のGd濃度及びGd異常度の最大値は,これまでの国内河川水の文献値と比較して最も高く,国外河川水のすべての報告値を含めて比較しても,ドイツのハベル川に次いで高いことが明らかになった.
著者
Masanari NAGASAKA Hayato YUZAWA Nobuhiro KOSUGI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.36, no.1, pp.95-105, 2020-01-10 (Released:2020-01-10)
参考文献数
100
被引用文献数
10

Soft X-ray absorption spectroscopy (XAS) involving excitation processes of a core electron to unoccupied states is an effective method to study local structures around excited C, N, and O atoms in liquid samples. Since soft X-rays are strongly absorbed by air and liquid itself, we have developed transmission-type liquid flow cells, where the absorbance of liquid samples can be easily reduced and optimized by controlling the liquid thickness. By using the transmission-mode XAS techniques, we have investigated local structures of several liquid samples such as concentration dependence of aqueous pyridine solutions and unexpected temperature-dependent structural changes in liquid benzene from the precise energy shift measurements in XAS spectra with the help of molecular dynamics simulation and inner-shell calculations. These XAS techniques are also applied to in situ/operando observation of chemical processes in solutions such as catalytic and electrochemical reactions.