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Analytica Chimica Acta

Bing Yuan, Xiangxu Jiang, Chu Yao, Meimei Bao, Jiaojiao Liu, Yujiang Dou, Yinze Xu, Yao He, Kai Yang, Yuqiang Ma
Metal-enhanced fluorescence shows great potential for improving the sensitivity of fluoroscopy, which has been widely used in protein and nucleic acid detection for biosensor and bioassay applications. In comparison with the traditional glass-supported metal nanoparticles (MNPs), the introduction of a silicon substrate has been shown to provide an increased surface-enhanced Raman scattering (SERS) effect due to the coupling between the MNPs and the semiconducting silicon substrate. In this work, we further study the fluorescence-enhanced effect of the silicon-supported silver-island (Ag@Si) plasmonic chips...
February 22, 2017: Analytica Chimica Acta
Dušan Kojić, Roumiana Tsenkova, Masato Yasui
In what appears to be a trivial operation in which the averaged spectrum of solvent is subtracted from the spectra of solutions, can be a misleading step in improving reproducibility of vibrational spectra. Near-infrared spectra of pure water and glycine solutions were used to quantify instrumental and spectral variations, and examine its influence on the reproducibility of difference spectra over a wide concentration range. Significant improvements were observed (fourfold), in comparison with the most commonly applied technique that uses an averaged spectrum of solvent...
February 22, 2017: Analytica Chimica Acta
Jennifer T Saville, Nicholas J C Smith, Janice M Fletcher, Maria Fuller
Impaired sulfatide catabolism is the primary biochemical insult in patients with the inherited neurodegenerative disease, metachromatic leukodystrophy (MLD), and sulfatide elevation in body fluids is useful in the diagnostic setting. Here we used mass spectrometry to quantify fourteen species of sulfatide, in addition to the deacetylated derivative, lyso-sulfatide, using high pressure liquid chromatography-electrospray ionisation-tandem mass spectrometry in both positive and negative ion mode. A single phase extraction of 0...
February 22, 2017: Analytica Chimica Acta
Hua Sang, Gaoyuan Lu, Yazhong Liu, Qiyue Hu, Weifeng Xing, Dongbing Cui, Fang Zhou, Jingwei Zhang, Haiping Hao, Guangji Wang, Hui Ye
Trastuzumab-MCC-DM1 (T-DM1) is an antibody-drug conjugate (ADC) that consists of a monoclonal antibody (mAb) trastuzumab non-cleavably linked to a cytotoxic drug DM1. During production, the DM1 agents were conjugated to the lysine residues of the mAb in a non-specific manner, yielding a heterogeneous mixture of ADC molecules that differ with respect to both the number and the conjugation sites of DM1 per mAb molecule. Since drug conjugation sites of ADC can significantly impact properties such as stability and pharmacokinetic behaviors, a rapid and reliable approach for conjugation site analysis of ADCs is highly demanded...
February 22, 2017: Analytica Chimica Acta
Guilong Peng, Qiang He, Ying Lu, Jing Huang, Jin-Ming Lin
In this paper, a rapid and simple method using magnetic multi-walled carbon nanotubes (MWCNTS), as a solid-phase extraction (SPE) sorbent, was successfully developed for extraction and preconcentration trace amounts of Cr(III) in water samples. The synthesized magnetic-MWCNTs nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). A rhodamine derivative (R1) was synthesized and characterized as a highly selective and sensitive fluorescent derivatizing agent for Cr(III)...
February 22, 2017: Analytica Chimica Acta
Astrid Foubert, Natalia V Beloglazova, Sarah De Saeger
Quantum dots (QDs) and colloidal gold nanoparticles (CG) were evaluated as labels for multiplex lateral flow immunoassay (LFIA) for determination of mycotoxins deoxynivalenol (DON), zearalenone (ZEN) and T2/HT2-toxin (T2/HT2) in cereal matrices. Both developed assays were based on the same immunoreagents (except for the labels), therefore their analytical characteristics could be objectively compared. For both LFIAs antigens (DON-ovalbumin (OVA), ZEN-OVA and T2-OVA) and rabbit anti-mouse immunoglobulin were immobilized on a nitrocellulose membrane as three test lines and one control line, respectively...
February 22, 2017: Analytica Chimica Acta
Francesca Di Turo, Noemí Montoya, Joan Piquero-Cilla, Caterina De Vito, Fulvio Coletti, Gabriele Favero, Antonio Doménech-Carbó
Voltammetry of microparticles (VMP) and electrochemical impedance spectroscopy (EIS) techniques, complemented by SEM-EDX and Raman spectroscopy, were applied to a set of 15 Roman bronze coins and one Tessera from the temple of Magna Mater (Rome, Italy). The archaeological site, dated back between the second half and the end of the 4th century A.D., presented a complicated stratigraphic context. Characteristic voltammetric patterns for cuprite and tenorite for sub-microsamples of the corrosion layers of the coins deposited onto graphite electrodes in contact with 0...
February 22, 2017: Analytica Chimica Acta
Yoric Gagnebin, David Tonoli, Pierre Lescuyer, Belen Ponte, Sophie de Seigneux, Pierre-Yves Martin, Julie Schappler, Julien Boccard, Serge Rudaz
Among the various biological matrices used in metabolomics, urine is a biofluid of major interest because of its non-invasive collection and its availability in large quantities. However, significant sources of variability in urine metabolomics based on UHPLC-MS are related to the analytical drift and variation of the sample concentration, thus requiring normalization. A sequential normalization strategy was developed to remove these detrimental effects, including: (i) pre-acquisition sample normalization by individual dilution factors to narrow the concentration range and to standardize the analytical conditions, (ii) post-acquisition data normalization by quality control-based robust LOESS signal correction (QC-RLSC) to correct for potential analytical drift, and (iii) post-acquisition data normalization by MS total useful signal (MSTUS) or probabilistic quotient normalization (PQN) to prevent the impact of concentration variability...
February 22, 2017: Analytica Chimica Acta
Slađana Strmečki, Mojmír Trefulka, Pavlína Zatloukalová, Michal Durech, Borivoj Vojtesek, Emil Paleček
Glycosylation of proteins plays an important role in health and diseases. At present new simple and inexpensive methods of glycoprotein analysis are sought. We developed a monoclonal antibody Manost 2.1 in mice after immunization with the adduct of mannan with Os(VI)temed complex (temed is N,N,N',N'-tetramethylethylenediamine). The specificity of this antibody to different biomolecules treated with Os(VI)temed was tested using dot blot immunoassay. Manost 2.1 showed specificity toward Os(VI)temed-modified polysaccharides, glycoproteins and ribonucleotide at the 3'-end in DNA...
February 22, 2017: Analytica Chimica Acta
Szymon Dziomba, Monica Araya-Farias, Claire Smadja, Myriam Taverna, Benjamin Carbonnier, N Thuy Tran
Determination of proteins and peptides is among the main challenges of today's bioanalytical chemistry. The application of microchip technology in this field is an exhaustively developed concept that aims to create integrated and fully automated analytical devices able to quantify or detect one or several proteins from a complex matrix. Selective extraction and preconcentration of targeted proteins and peptides especially from biological fluids is of the highest importance for a successful realization of these microsystems...
February 22, 2017: Analytica Chimica Acta
Biao Gu, Liyan Huang, Wei Su, Xiaoli Duan, Haitao Li, Shouzhuo Yao
A new benzothiazole-based fluorescent probe 2-(benzo[d]thiazol-2-yl)-4-(1,3- dithian-2-yl)phenol (BT) with two different reaction sites, a thioacetal group (site 1 for Hg(2+)), and O and N atoms of the benzothiazole dye (site 2 for Cu(2+)), was designed and synthesized. The probe BT showed ratiometric fluorescent response to Hg(2+) and fluorescence quenching behavior to Cu(2+), which induces naked-eye fluorescent color changes from green to blue and colorless, respectively. Moreover, it displayed highly sensitivity and selectivity toward Hg(2+) and Cu(2+) without interference from other metal ions...
February 15, 2017: Analytica Chimica Acta
Jacqueline Marques Petroni, Bruno Gabriel Lucca, Valdir Souza Ferreira
This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate. Morphological structure and electrochemical behavior of the carbon electrodes were investigated by scanning electron microscopy and cyclic voltammetry...
February 15, 2017: Analytica Chimica Acta
Naoko Arashida, Rumi Nishimoto, Masashi Harada, Kazutaka Shimbo, Naoyuki Yamada
Amino acids and their related metabolites play important roles in various physiological processes and have consequently become biomarkers for diseases. However, accurate quantification methods have only been established for major compounds, such as amino acids and a limited number of target metabolites. We previously reported a highly sensitive high-throughput method for the simultaneous quantification of amines using 3-aminopyridyl-N-succinimidyl carbamate as a derivatization reagent combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS)...
February 15, 2017: Analytica Chimica Acta
Alkiviadis Gourgiotis, Thomas Ducasse, Evelyne Barker, Patrick Jollivet, Stéphane Gin, Sylvain Bassot, Charlotte Cazala
High-level, long-lived nuclear waste arising from spent fuel reprocessing is vitrified in silicate glasses for final disposal in deep geologic formations. In order to better understand the mechanisms driving glass dissolution, glass alteration studies, based on silicon isotope ratio monitoring of (29)Si-doped aqueous solutions, were carried out in laboratories. This work explores the capabilities of the new type of quadrupole-based ICP-MS, the Agilent 8800 tandem quadrupole ICP-MS/MS, for accurate silicon isotope ratio determination for alteration studies of nuclear waste glasses...
February 15, 2017: Analytica Chimica Acta
Marcos Tascon, Leonardo G Gagliardi, Fernando Benavente
β-carboline alkaloids of the harmala group (HAlks)-a family of compounds with pharmacologic effects-can be found at trace levels (<25 μg kg(-1) algae) in the edible invasive algae Undaria pinnatifida, known commonly as wakame. In this study, we present a simple and sensitive method to detect and quantify at low parts-per-trillion levels the six HAlks more frequently found in those plants. The method is based on on-line solid phase extraction capillary electrophoresis mass spectrometry using a C18 sorbent...
February 15, 2017: Analytica Chimica Acta
Jiewei Deng, Tiantian Yu, Yao Yao, Qi Peng, Lijuan Luo, Baowei Chen, Xiaowei Wang, Yunyun Yang, Tiangang Luan
In this study, a surface-coated wooden-tip electrospray ionization mass spectrometry (SCWT-ESI-MS) method was developed for rapid and sensitive analysis of trace fluoroquinolone and macrolide antibiotics in water. First, a SCWT solid-phase microextration (SPME) probe was prepared, via silanization and sulfonation for modification of a layer of adsorbent containing both C8-chain and sulfo group on the surface of wooden tips. Then, the SCWT-SPME probe was applied for extraction of trace fluoroquinolone and macrolide antibiotics in water...
February 15, 2017: Analytica Chimica Acta
Ruiyi Li, Tingting Yang, Zaijun Li, Zhiguo Gu, Guangli Wang, Junkang Liu
Integration of noble metal nanomaterials on graphene nanosheets potentially paves one way to improve their electronic, chemical and electrochemical properties. The study reported synthesis of palladium@gold nanoalloys/nitrogen and sulphur-functionalized multiple graphene aerogel composite (Pd@Au/N,S-MGA). The as-prepared composite offers a well-defined three-dimensional architecture with rich of mesopores. The Pd@Au nanoalloys were dispersed on the graphene framework networks and their active sites were fully exposed...
February 15, 2017: Analytica Chimica Acta
Neirivaldo Cavalcante da Silva, Cláudia Jéssica Cavalcanti, Fernanda Araújo Honorato, Jose Manuel Amigo, Maria Fernanda Pimentel
The interest in performing in field measures using portable instruments is growing increasingly. Calibration transfer techniques can be used to enable models, predicted values or spectra obtained in a benchtop instrument be used in portable instrument, saving money and time required for a complete recalibration. Most of the calibration transfer methods require a set of transfer samples which spectra have to be acquired in both spectrometers. The present work evaluates the use of virtual standards as transfer samples in the reverse standardization (RS) method in order to standardize very dissimilar spectral responses of fuel samples (gasoline and biodiesel blends) from a high-resolution benchtop Frontier FT-NIR (PerkinElmer) spectrometer and a handheld MicroNIR™1700 (JDSU)...
February 15, 2017: Analytica Chimica Acta
Jacopo Acquarelli, Twan van Laarhoven, Jan Gerretzen, Thanh N Tran, Lutgarde M C Buydens, Elena Marchiori
In this work we show that convolutional neural networks (CNNs) can be efficiently used to classify vibrational spectroscopic data and identify important spectral regions. CNNs are the current state-of-the-art in image classification and speech recognition and can learn interpretable representations of the data. These characteristics make CNNs a good candidate for reducing the need for preprocessing and for highlighting important spectral regions, both of which are crucial steps in the analysis of vibrational spectroscopic data...
February 15, 2017: Analytica Chimica Acta
Koji Karasawa, Shiomi Haraya, Sachie Okubo, Hidetoshi Arakawa
Five components (hydrogen peroxide, methylglyoxal, dihydroxyacetone, fructose and glucose) of New Zealand manuka honey (Leptospermum scoparium) were analyzed using lucigenin chemiluminescence high-performance liquid chromatography (lucigenin-CL-HPLC). We focused on active oxygen species produced from the components in order to easily detect these five components contained in manuka honey. H2O2 and O2(-) generated from these components were identified by lucigenin-CL and electron spin resonance (ESR), and the bactericidal effect of ROS was confirmed using E...
February 15, 2017: Analytica Chimica Acta
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