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Analytica Chimica Acta

Datong Wu, Qiuhong Yin, Pengfei Cai, Xiaoyong Zhao, Yuanjiang Pan
Novel task-specific ionic liquids derived from (S)-phenyl amino acid were prepared as a chiral sensor for the first time. It was found that the ionic liquids exhibited different chiral visual responses to the enantiomers. When (S)-tryptophan was treated with the sensor and Cu(II) in water, the clear solution would change to a sapphire suspension. Differently, another enantiomer could not produce the precipitate. Furthermore, the enantiomers could generate different colors in DMSO under the same conditions. The substantial difference contributes to the easy discrimination with visual determination...
April 15, 2017: Analytica Chimica Acta
Samer Doughan, Uvaraj Uddayasankar, Aparna Peri, Ulrich J Krull
Monodisperse aqueous upconverting nanoparticles (UCNPs) were covalently immobilized on aldehyde modified cellulose paper via reductive amination to evaluate the multiplexing capacity of luminescence resonance energy transfer (LRET) between UCNPs and quantum dots (QDs). This is the first account of a multiplexed bioassay strategy that demonstrates the principle of use of a single form of UCNP as donor and three different color emitting QDs as acceptors to concurrently determine three analytes. Broad absorbance profiles of green, orange and red QDs that spanned from the first exciton absorption peak to the UV region were in overlap with a blue emission band from UCNPs composed of NaYF4 that was doped with 30% Yb(3+), 0...
April 15, 2017: Analytica Chimica Acta
Alexey V Samokhvalov, Irina V Safenkova, Sergei A Eremin, Anatoly V Zherdev, Boris B Dzantiev
A new strategy for sensitive fluorescence polarisation (FP) analysis is proposed which uses aptamer as the receptor and anchor protein modules as the enhancers by including the aptamers in complexes with protein modules. This approach is based on increasing the size differences of bound and unbound fluorophores. The strategy was applied in an ochratoxin A (ОТА) assay with the competitive binding of fluorophore-labelled and free OTA with aptamer-based receptors. We showed that the binding of labelled OTA with aptamer included in complexes with anchors led to higher a FP than binding with free aptamer...
April 15, 2017: Analytica Chimica Acta
Lei Zhan, Wen Bi Wu, Lin Yang, Cheng Zhi Huang
The timely detection of infectious pathogen is critical in clinical early diagnosis and treatment of infectious diseases. Plasmonic enzyme-linked immunosorbent assay (ELISA), by means of enzyme-mediated growth or aggregation of AuNPs, has received considerable attention because it allows a naked-eye detection of target in very low numbers. In this work, a dual-signal amplified plasmonic ELISA combined the high loading capacity of magnetic beads with the establishing stimulation effect of zinc ion has been developed to detect RSV as a model pathogen based on alkaline phosphatase-triggered dispersion of aggregated AuNPs...
April 15, 2017: Analytica Chimica Acta
Bjorn J A Berendsen, Thijs Meijer, Hans G J Mol, Leen van Ginkel, Michel W F Nielen
According to EU legislation a confirmatory method used for residue analysis should be able to confirm the identity of a compound beyond reasonable doubt. To provide an adequate instrumental set-up, Commission Decision 2002/657/EC introduced the concept of "identification points". A second aspect to assure unequivocal confirmation, is the establishment of ion ratio and retention time criteria. Currently, the gold standard for confirmatory analysis of most veterinary drug residues is liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) in selected reaction monitoring (SRM) acquisition mode, isolating one precursor ion and monitoring two a priori selected product ions, yielding 4 identification points...
April 15, 2017: Analytica Chimica Acta
Dan Zhou, Shuai Guo, Mo Zhang, Yujie Liu, Tianjing Chen, Zhili Li
With the development of matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI), molecular interrogation of tissue sections over a wide mass range has become feasible, but small molecule analysis is still far from being fully reached due to the limited sensitivity and matrix interference. Herein, graphene oxide (GO) is used as a MALDI matrix to image small molecules in tissues in negative ion mode. Finally, 212 of molecules including 190 of lipids and 22 of low molecular weight metabolites were detected and spatially visualized in mouse brain tissue sections without the interference of matrix ions/clusters, and the structures of 69 of the lipids were confirmed by using in situ tandem mass spectrometry...
April 15, 2017: Analytica Chimica Acta
María J Trujillo-Rodríguez, Verónica Pino, Elefteria Psillakis, Jared L Anderson, Juan H Ayala, Evangelia Yiantzi, Ana M Afonso
This work proposes a new vacuum headspace solid-phase microextraction (Vac-HSSPME) method combined to gas chromatography-flame ionization detection for the determination of free fatty acids (FFAs) and phenols. All target analytes of the multicomponent solution were volatiles but their low Henry's Law constants rendered them amenable to Vac-HSSPME. The ability of a new and easy to construct Vac-HSSPME sampler to maintain low-pressure conditions for extended sampling times was concurrently demonstrated. Vac-HSSPME and regular HSSPME methods were independently optimized and the results were compared at all times...
April 15, 2017: Analytica Chimica Acta
Kuan Jiang, He Zhu, Cong Xiao, Ding Liu, Garrett Edmunds, Liuqing Wen, Cheng Ma, Jing Li, Peng George Wang
Reductive amination is an indispensable method for glycomic analysis, as it tremendously facilitates glycan characterization and quantification by coupling functional tags at the reducing ends of glycans. However, traditional in-solution derivatization based approach for the preparation of reductively aminated glycans is quite tedious and time-consuming. Here, a simpler and more efficient strategy termed solid-phase reductive amination was investigated. The general concept underlying this new approach is to streamline glycan extraction, derivatization, and purification on non-porous graphitized carbon sorbents...
April 15, 2017: Analytica Chimica Acta
Nan Yu, Zhen Wang, Chaochen Wang, Jing Han, Huaiyu Bu
In this report, an ultrasensitive electrochemical biosensor for miR-21 detection was designed on the basis of a padlock exponential rolling circle amplification (P-ERCA) assay and CoFe2O4 magnetic nanoparticles (CoFe2O4 MNPs) by nanoelectrocatalysis without a substrate for signal amplification. Here, to improve catalytic efficiency, nanocatalyst (CoFe2O4 MNPs) and redox molecule (Tb) were co-immobilized onto the graphene (Gra) surface and formed Au@CoFe2O4/Tb-Gra probe. The obtained probe exhibits high-performance Tb catalysis by reducing the interaction distance between CoFe2O4 MNPs and Tb, and importantly, the detection sensitivity is significantly improved even in the absence of substrate (H2O2)...
April 15, 2017: Analytica Chimica Acta
Åsmund Rinnan, Sander Bruun, Jane Lindedam, Stephen R Decker, Geoffrey B Turner, Claus Felby, Søren Balling Engelsen
The combination of NIR spectroscopy and chemometrics is a powerful correlation method for predicting the chemical constituents in biological matrices, such as the glucose and xylose content of straw. However, difficulties arise when it comes to predicting enzymatic glucose and xylose release potential, which is matrix dependent. Further complications are caused by xylose and glucose release potential being highly intercorrelated. This study emphasizes the importance of understanding the causal relationship between the model and the constituent of interest...
April 15, 2017: Analytica Chimica Acta
Jia-Fu Li, Xia Yan, Yun-Long Wu, Mei-Juan Fang, Zhen Wu, Ying-Kun Qiu
An analytical two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography (2D NPLC × RPLC) system was constructed with a newly developed thermal evaporation assisted adsorption (TEAA) interface. This novel TEAA interface with heating temperature above solvent boiling point allowed fast removal of organic NPLC solvent and successfully solved the solvent incompatibility problem between NPLC and RPLC. The system achieved rapid on-line solvent exchange between the two dimensions within a short modulation time of 190 s and was applied in the analysis of an extract from the skin of Bufo bufo gargarizans...
April 15, 2017: Analytica Chimica Acta
Hengye Li, Xuemeng Zhang, Lin Zhang, Xiaojin Wang, Fenying Kong, Dahe Fan, Lei Li, Wei Wang
A silica stationary phase was designed and synthesized through the co-functionalization of silica with Wulff-type phenylboronate and C12 for mixed-mode liquid chromatography applications. The as-synthesized stationary phase was characterized by elemental analysis and Fourier Transform-InfraRed Spectroscopy (FT-IR). Retention mechanisms, including boronate affinity (BA), reversed-phase (RP) and anion-exchange (AE), were involved. Retention mechanism switching was easily realized by adjustment of the mobile phase constitution...
April 15, 2017: Analytica Chimica Acta
N Salgueiro-González, S Muniategui-Lorenzo, P López-Mahía, D Prada-Rodríguez
In the last decade, the impact of alkylphenols and bisphenol A in the aquatic environment has been widely evaluated because of their high use in industrial and household applications as well as their toxicological effects. These compounds are well-known endocrine disrupting compounds (EDCs) which can affect the hormonal system of humans and wildlife, even at low concentrations. Due to the fact that these pollutants enter into the environment through waters, and it is the most affected compartment, analytical methods which allow the determination of these compounds in aqueous samples at low levels are mandatory...
April 15, 2017: Analytica Chimica Acta
Xinyue Liu, Kalib St Ange, Xiaohua Wang, Lei Lin, Fuming Zhang, Lianli Chi, Robert J Linhardt
Heparin is a structurally complex, polysaccharide anticoagulant derived from livestock, primarily porcine intestinal tissues. Low molecular weight (LMW) heparins are derived through the controlled partial depolymerization of heparin. Increased manufacturing and regulatory concerns have provided the motivation for the development of more sophisticated analytical methods for determining both their structure and pedigree. A strategy, for the comprehensive comparison of parent heparins and their LMW heparin daughters, is described that relies on the analysis of monosaccharide composition, disaccharide composition, and oligosaccharide composition...
April 8, 2017: Analytica Chimica Acta
Ruo-Jing Fan, Fang Zhang, Xiu-Ping Chen, Wan-Shu Qi, Qing Guan, Tuan-Qi Sun, Yin-Long Guo
The present work focused on the high-throughput screening and quantitation of guanidino compounds (GCs) and ureido compounds (UCs) in human thyroid tissues. The strategy employed benzylic rearrangement stable isotope labeling (BRSIL) for the sample preparation and then detection using liquid chromatography-drift tube ion mobility spectrometry-quadrupole time of flight mass spectrometry (LC-DTIMS-QTOF MS). A short reversed-phase LC realized an on-line desalting and a measurement cycle of 5.0 min. DTIMS separation enhanced the better specificity and selectivity for the benzil labeled GCs and UCs...
April 8, 2017: Analytica Chimica Acta
Beatrice Campanella, Lorenzo Biancalana, Lucia D'Ulivo, Massimo Onor, Emilia Bramanti, Zoltan Mester, Enea Pagliano
The high toxicity of cyanide, along with its widespread industrial use, has fuelled interest in the development of analytical methods for its determination in complex matrices. In this study, we propose a novel approach for the measurement of total cyanide in soil samples based on single-step derivatization with pentafluorobenzyl bromide (F5Bn-Br) followed by quantitation with gas chromatography mass spectrometry in negative chemical ionization mode. The reaction between CN(-) and F5Bn-Br resulted in the identification of several derivatives such as F5Bn-CN, (F5Bn)(F5Ph)CH-CN, and (F5Bn)2(F5Ph)C-CN...
April 8, 2017: Analytica Chimica Acta
Yingjie Li, Jiping Zhu
Thermal desorption (TD) GC/MS has been used for the analysis of polycyclic aromatic hydrocarbons (PAHs) and other semi-volatile organic compounds. However, thermal desorption recovery of PAHs have not been well studied and the cause of PAH residues in a TD system has not been clearly understood. Our results showed that low volatility of PAHs can lead to their incomplete recovery in a TD system: for the PAHs with low vapour pressures, up to 10% and 3% could be lost in a two-stage (TS) TD system and a short-path (SP) TD system, respectively...
April 8, 2017: Analytica Chimica Acta
Kochaporn Chullasat, Piyaluk Nurerk, Proespichaya Kanatharana, Pamornrat Kueseng, Thanyaporn Sukchuay, Opas Bunkoed
A hybrid monolith sorbent of polypyrrole-coated graphene oxide embedded in polyvinyl alcohol cryogel was prepared and used as an effective solid phase extraction sorbent for the determination of trace sulfonamides. The large surface areas with many adsorption sites of polypyrrole and graphene oxide facilitated the high adsorption of sulfonamides via hydrogen bonding, π-π and hydrophobic interactions. The high porosity of the polyvinyl alcohol cryogel helped to reduce the back pressure that occurs in a conventional packed solid phase extraction cartridge...
April 8, 2017: Analytica Chimica Acta
Daniel W Cook, Mackenzie L Burnham, David C Harmes, Dwight R Stoll, Sarah C Rutan
Comprehensive two-dimensional liquid chromatography (LC × LC) has been gaining popularity for the analysis of complex samples in a wide range of fields including metabolomics, environmental analysis, and food analysis. While LC × LC can provide greater chromatographic resolution than one-dimensional LC (1D-LC), overlapping peaks are often still present in separations of complex samples, a problem that can be alleviated by chemometric curve resolution techniques such as multivariate curve resolution-alternating least squares (MCR-ALS)...
April 8, 2017: Analytica Chimica Acta
Larissa Naida Rosa, Luana Caroline de Figueiredo, Elton Guntendorfer Bonafé, Aline Coqueiro, Jesuí Vergílio Visentainer, Paulo Henrique Março, Douglas N Rutledge, Patrícia Valderrama
The ComDim chemometrics method for multi-block analysis was employed to evaluate thirty-two vegetable oil samples analyzed by near infrared (NIR) and ultraviolet-visible (UV-Vis) spectroscopy, and by Gas Chromatography with flame ionization detection (GC-FID) for their fatty acids composition. This unsupervised pattern recognition method was able to extract information from the tables of results that could be presented in informative graphs showing the relationship between the samples through the scores, the predominance of information in particular tables through the saliences and the contribution of the variables in each table which were responsible for the similarities observed in the samples, through the loadings plots...
April 8, 2017: Analytica Chimica Acta
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