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Analytical and Bioanalytical Chemistry

Xianzhang Huang, Qiaoxuan Zhang, Songbai Zheng, Jianbing Wang, Liqiao Han, Haibiao Lin, Peifeng Ke, Junhua Zhuang, Zhimin Tim Cao
A candidate reference measurement procedure (RMP) for measurement of unconjugated estriol in human serum has been developed and validated. The proposed method is highly reliable and uses isotope dilution coupled with liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) and requires no derivatization. An appropriate amount of serum was accurately weighed and spiked with an isotopically labeled internal standard. Unconjugated estriol and its internal standard were extracted from serum matrix using liquid-liquid extraction prior to reversed-phase LC-MS/MS...
July 14, 2018: Analytical and Bioanalytical Chemistry
Sanlei Xie, Kai Wen, Jie Xie, Yongjun Zheng, Tao Peng, Jianyi Wang, Kai Yao, Shuangyang Ding, Haiyang Jiang
A sensitive competitive immunoassay with simple operation was developed for the detection of the anti-virus drug amantadine (AMD). The single-chain variable fragment (scFv) antibody against AMD was site-specific biotinylated and overexpressed as a secreted body in Escherichia coli AVB101. Horseradish peroxidase-labeled streptavidin-biotinylated scFv antibody (HRP-SA-BIO-scFv) could specifically bind to AMD-functionalized magnetic beads (MBs) and then the immune complexes were separated from the matrix solution by magnet...
July 14, 2018: Analytical and Bioanalytical Chemistry
Mona M Khamis, Nancy Klemm, Darryl J Adamko, Anas El-Aneed
Targeted metabolomics requires accurate and precise quantification of candidate biomarkers, often through tandem mass spectrometric (MS/MS) analysis. Differential isotope labeling (DIL) improves mass spectrometric (MS) analysis in metabolomics by derivatizing metabolites with two isotopic forms of the same reagent. Despite its advantages, DIL-liquid chromatographic (LC)-MS/MS can result in substantial increase in workload when fully validated quantitative methods are required. To decrease the workload, we hypothesized that single point calibration or relative quantification could be used as alternative methods...
July 13, 2018: Analytical and Bioanalytical Chemistry
Khalid M Omer
Carbon quantum dots are becoming powerful fluorophore materials for metal ion analysis. Here, highly passivated green phosphorous and nitrogen co-doped carbon quantum dots (C-dots) were prepared using low-temperature carbonization route. Strong green fluorescence emission around 490 nm and excitation wavelength independent C-dots were obtained. Morphological, surface, and optical properties of the C-dots were characterized. Fluorescence emission of C-dots was quenched selectively by copper ions and restored by adding copper chelators, such as EDTA and sulfide ions...
July 13, 2018: Analytical and Bioanalytical Chemistry
Andreas Schinkovitz, Séverine Boisard, Ingrid Freuze, Junichi Osuga, Norbert Mehlmer, Thomas Brück, Pascal Richomme
Matrix-free laser desorption ionization (LDI) is a rapid and versatile technique for the ionization of small, UV-light-absorbing molecules. Indeed, many natural products such as polyphenols exhibit inherent LDI properties, potentially facilitating their detection from highly complex samples such as crude extracts. With this in mind, the present work thoroughly evaluated the potential of LDI as an analytical tool for the chemical profiling and differentiation of propolis samples obtained from different global regions...
July 12, 2018: Analytical and Bioanalytical Chemistry
Sathisha Kamanna, Julianne Henry, Nico Voelcker, Adrian Linacre, K Paul Kirkbride
Violent contact between individuals during a crime can result in body fluids becoming trapped under the fingernails of the individuals involved. The traces under fingernails represent valuable forensic evidence because DNA profiling can indicate from whom the trace originated and proteomic methods can be used to determine the type of fluid in the trace, thus providing evidence as to the circumstances surrounding the crime. Here, we present an initial study of an analytical strategy that involves two complementary techniques, direct PCR DNA profiling and direct mass spectrometry-based protein biomarker detection, for the comprehensive examination of traces of biological fluids gathered from underneath fingernails...
July 12, 2018: Analytical and Bioanalytical Chemistry
Yapiao Li, Linlin Sun, Qiang Zhao
Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins and draws great concern in health and food safety. A DNA aptamer against AFB1 having a stem-loop structure shows high binding affinity to AFB1 and promise in assay development for AFB1 detection. Based on the structure-switching property of the aptamer, we report an aptamer fluorescence assay for AFB1 detection. Aptamer with fluorescein (FAM) label at 5' end was used as affinity ligand, while its short complementary DNA (cDNA) with BHQ1 (black hole quencher 1) label at 3' end was used as a quencher...
July 12, 2018: Analytical and Bioanalytical Chemistry
Timothy R Baker, Brian T Regg
An approach has been developed to characterize the individual chemical constituents of botanicals. The challenge was to identify and quantitate the significant analytes in these complex mixtures, largely in the absence of authentic standards. The data-rich information content generated by this three-detector configuration was specifically intended to be used to conduct safety and/or quality evaluations for complex botanical mixtures, on a chemical constituent basis. The approach utilized a broad gradient UHPLC chromatographic separation...
July 11, 2018: Analytical and Bioanalytical Chemistry
Chunyuan Tian, Shuang Zhang, Xuming Zhuang, Haihua Wang, Dandan Chen, Feng Luan, Tao He, Wei He, Yang Qiu
Gold nanoparticles supported on graphene oxide with flagella as the template were developed as an electrochemical sensor for the detection of hydrogen peroxide (H2 O2 ) in serum. The flagella-Au nanoparticles composite and graphene oxide were dropped onto a glassy carbon electrode (GCE) to form a new H2 O2 electrochemical sensor. The structure morphology of the prepared sensor was characterized by transmission electron microscopy (TEM), and the electrocatalytic performance towards H2 O2 reduction was evaluated by cyclic voltammetry (CV) and amperometric methods...
July 10, 2018: Analytical and Bioanalytical Chemistry
Hyeyoung Kwon, Michelangelo Anastassiades, Daniela Dörk, Su-Myoung Hong, Byeong-Chul Moon
Matrix effects (MEs) can adversely affect quantification in pesticide residue analysis using GC. Analyte protectants (APs) can effectively interact with and mask active sites in the GC system, and are added individually or in combination to sample extracts and calibration solutions to minimize errors related to MEs. Unfortunately, APs cannot sufficiently compensate for MEs in all cases. Plant extracts, containing a broad range of natural compounds with AP properties, can also be used for this purpose. In this study, the applicability of cucumber extract as a natural AP mixture was investigated both alone and in combination with traditional APs...
July 9, 2018: Analytical and Bioanalytical Chemistry
Yida Zhang, Huawei Cao, Qiangwei Huang, Xiaoyan Liu, Haixia Zhang
Transferrin (TrF) is a very important human body glycoprotein and a clinical biomarker which controls the body's iron ion channels and iron ion balance. Any change in TrF concentration and isoform also reflects the emergence of some diseases. In this work, we prepared magnetic molecularly imprinted nanoparticles (deep eutectic solvent-molecular imprinting polymers [DES-MIPs]) with a deep eutectic solvent (DES) as a functional monomer to separate TrF in human serum. The DES dosage for MIP, pH value, and time for adsorption have been optimized, and these materials show special adsorption properties for TrF...
July 7, 2018: Analytical and Bioanalytical Chemistry
Alejandro Orellana-Silla, Sergio Armenta, Miguel de la Guardia, Josep V Mercader, Francesc A Esteve-Turrillas
The advantages of using smart materials as immunosorbents in the analysis of complex matrices by ion mobility spectrometry (IMS) have been highlighted in this study. A novel analytical method has been proposed for the sensitive, selective, and fast determination of residues of the plant growth regulator forchlorfenuron in fruit juices. Three different monoclonal antibodies (s3#22, p2#21, and p6#41) were employed for the production of immunosorbents, based on Sepharose gel beads, which were characterized in terms of loading capacity, solvent resistance, and repeatability for its use in solid-phase extraction (SPE)...
July 7, 2018: Analytical and Bioanalytical Chemistry
Philipp Fruhmann, Ana Sanchis, Lisa Mayerhuber, Tünde Vanka, Christoph Kleber, J-Pablo Salvador, M-Pilar Marco
The study of an enzyme-linked immunosorbent assay (ELISA) and an amperometric biosensor for the detection of the pyrethroid deltamethrin in seawater is reported. The preparation of specific polyclonal antibodies is addressed using two immunizing haptens based on deltamethrin and cypermethrin compounds, with a spacer arm placed at the cyano residue in the pyrethroid structure. Different conjugates based on bovine serum albumin and aminodextran are prepared depending on the lipophilic profile of the competitor haptens studied...
July 7, 2018: Analytical and Bioanalytical Chemistry
Akimasa Fujihara, Yusuke Okawa
Chiral and molecular recognition between amino acid and sugar molecules and their implications for chemical evolution were investigated using a tandem mass spectrometer equipped with an electrospray ionization source and a cold ion trap. Ultraviolet photodissociation of mass-selected and temperature-controlled gas-phase noncovalent complexes of protonated tryptophan (Trp) and monosaccharide enantiomers, such as aldohexose, aldopentose, and deoxyhexose, was examined as a model for chemical evolution in interstellar molecular clouds...
July 7, 2018: Analytical and Bioanalytical Chemistry
George C Rhoderick, Michael E Kelley, Lyn Gameson, Kimberly J Harris, Joseph T Hodges
The noble gases, namely neon, argon, krypton and xenon, have many uses including in incandescent and gas discharge lighting, in plasma televisions, shielding gas in welding, in lasers for surgery and semiconductors, and in magnetic resonance imaging (MRI) of the lungs. When incorporating these noble gases in industries, especially the medical field, it is important to know accurately the composition of the noble gas mixture. Therefore, there is a need for accurate gas standards that can be used to determine the noble gas amount-of-substance fraction in the appropriate mixture application...
July 6, 2018: Analytical and Bioanalytical Chemistry
Maria Elvira Carbone, Rosanna Ciriello, Pasquale Moscarelli, Federica Boraldi, Giuliana Bianco, Antonio Guerrieri, Brigida Bochicchio, Antonietta Pepe, Daniela Quaglino, Anna Maria Salvi
This investigation was undertaken to explore the mutual recognition of the pentapeptide (ValGlyGlyValGly)n , a hydrophobic elastin-like peptide (ELP), suspended in deionized water in monomer (n = 1) and trimer (n = 3) forms and the outer surface of a very thin, insulating polymer, poly(ortho-aminophenol) (PoAP), electrochemically grown on a platinum foil by cyclic voltammetry in a neutral medium (phosphate-buffered saline, I = 0.1M) immersed in the suspension. As a prior task, the proved propensity of the ValGlyGlyValGly sequence, at the given minimal length (three or more repeats), to self-assemble into amyloid-like fibrils when solubilized in an aqueous environment was considered within the framework of testing PoAP surfaces for the specific detection of amyloid precursors...
July 6, 2018: Analytical and Bioanalytical Chemistry
Sebastian Primpke, Marisa Wirth, Claudia Lorenz, Gunnar Gerdts
The identification of microplastics becomes increasingly challenging with decreasing particle size and increasing sample heterogeneity. The analysis of microplastic samples by Fourier transform infrared (FTIR) spectroscopy is a versatile, bias-free tool to succeed at this task. In this study, we provide an adaptable reference database, which can be applied to single-particle identification as well as methods like chemical imaging based on FTIR microscopy. The large datasets generated by chemical imaging can be further investigated by automated analysis, which does, however, require a carefully designed database...
July 6, 2018: Analytical and Bioanalytical Chemistry
M D Fernández-Ramos, M L Aguayo-López, I Pérez de Vargas-Sansalvador, L F Capitán-Vallvey
This work presents a study on the influence of eight different ionic liquids (ILs) in the composition of dry membranes used for gaseous CO2 optical sensing. The presence of CO2 causes a displacement of a colorimetric pH indicator toward its acid form that increases the emission intensity of the luminophore by an inner filter process. The influence of ILs in the membrane on the stability and dynamic behavior-usually the main drawbacks of these sensors-of the membranes is studied. The characterization of the different membranes prepared was carried out and the discussion of the results is presented...
July 5, 2018: Analytical and Bioanalytical Chemistry
Hang Zhang, Jun Ruan, Weiwei Liu, Xuerui Jiang, Tianyu Du, Hui Jiang, Alberto Pasquarelli, Kay-Eberhard Gottschalk, Xuemei Wang
The authors would like to call the reader's attention to the fact that unfortunately Alberto Pasquarelli's and Kay-Eberhard Gottschalk's affiliations were wrong in the original publication.
July 5, 2018: Analytical and Bioanalytical Chemistry
Ryan F LeBouf, Dru A Burns, Anand Ranpara, Kathleen Attfield, Leonard Zwack, Aleksandr B Stefaniak
The use of electronic nicotine delivery systems continues to gain popularity, and there is concern for potential health risks from inhalation of aerosol and vapor produced by these devices. An analytical method was developed that provided quantitative and qualitative chemical information for characterizing the volatile constituents of bulk electronic cigarette liquids (e-liquids) using a static headspace technique. Volatile organic compounds (VOCs) were screened from a convenience sample of 146 e-liquids by equilibrating 1 g of each e-liquid in amber vials for 24 h at room temperature...
July 4, 2018: Analytical and Bioanalytical Chemistry
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