915 results match your criteria Analytical Methods[Journal]

An electrochemical sensor based on hierarchical nickel oxide nanostructures doped with indium ions for voltammetric simultaneous determination of sunset yellow and tartrazine colorants in soft drink powders.

Anal Methods 2021 May 13. Epub 2021 May 13.

Department of Chemistry, Kerman Branch, Islamic Azad University, Kerman, Iran.

The current study was designed to develop a single-step and simple approach to effectively fabricate three-dimensional raspberry-like In3+/NiO hierarchical nanostructures (In3+/NiO RLHNSs) as a modifier, which was subsequently characterized by the techniques of X-ray diffraction (XRD), energy dispersive spectrometry (EDS) and field emission scanning electron microscopy (FE-SEM). The new prepared nano-modifier was practically used to co-detect electrochemically sunset yellow and tartrazine dyes. Potent sensitivity and acceptable selectivity were obtained for the produced In3+/NiO RLHNSs to co-detect both the food colorants, thus providing oxidation peaks in differential pulse voltammetry (DPV) with a peak potential separation of ca. Read More

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What's novel in the new Eurachem guide on uncertainty from sampling?

Anal Methods 2020 May;12(17):2295-2297

A second edition of the Eurachem guide, Measurement uncertainty arising from sampling (UfS),1 has recently been published (Fig. 1), in collaboration with CITAC, Eurolab, Nordtest and the Royal Society of Chemistry's Analytical Methods Committee. This Technical Brief aims to explain how this new second edition differs significantly from the first edition that was published in 2007. Read More

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Hand-held X-ray fluorescence spectrometry.

Anal Methods 2019 May;11(18):2498-2501

This Technical Brief describes the evolution of hand-held X-ray fluorescence instrumentation designed for inorganic elemental analysis outside the confines of a laboratory, thereby offering the capability for in situ analysis. As well as providing an overview of the instrumentation, it aims to inform both analysts and less-technically aware users how the technique may be used for a comprehensive assessment of a complex measurement problem and enable on-site decision making. Read More

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Laser-induced breakdown spectroscopy (LIBS) in cultural heritage.

Anal Methods 2019 Nov;11(45):5833-5836

Laser-induced breakdown spectroscopy (LIBS) is a versatile technique that provides nearly instant elemental analysis of materials, both in the laboratory and in the field. This is done by focusing a short laser pulse on the surface of the sample, or object, studied and analysing the resulting spectrum from the laser-induced plasma. LIBS has been employed in the analysis of archaeological and historical objects, monuments and works of art for assessing the qualitative, semi-quantitative and quantitative elemental content of materials such as pigments, pottery, glass, stone, metals, minerals and fossils. Read More

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November 2019

The edge of reason: reporting and inference near the detection limit.

Anal Methods 2020 Jan;12(3):401-403

Although the general concept of a detection limit as a lower practical operating limit for an analytical method is widely understood, the precise interpretation of results near the IUPAC limit of detection is rarely as well understood or implemented. It is important to distinguish between statements about the analytical result, which is known, and inferences about the true value, which are not known. It is also crucial to understand that there are at least two quite different limits involved and that the limit most commonly referred to as the 'limit of detection' is, surprisingly, not intended as the criterion for detection of an analyte. Read More

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January 2020

The role of accreditation in ensuring sampling quality.

Anal Methods 2019 Jul;11(26):3358-3360

Accreditation has proved effective in ensuring the quality of analytical measurements but is now increasingly being applied to primary sampling, as the first part of the measurement process. Several international standards relevant to accreditation of sampling are available, either for organisations undertaking the sampling (ISO/IEC 17025 or 17020), or for the certification of the sampler (i.e. Read More

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To or not to : the use of -values in analytical science.

Anal Methods 2020 Feb;12(6):872-874

A significance test can be performed by calculating a test statistic, such as Student's t or chi-squared, and comparing it with a critical value for the corresponding distribution. If the test statistic crosses the critical value threshold, the test is considered "significant". The critical value is chosen so that there is a low probability - often 5% (for "95% confidence") - of obtaining a significant test result by chance alone. Read More

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February 2020

Why do we need the uncertainty factor?

Anal Methods 2019 Apr;11(15):2105-2107

The uncertainty factor is a new way to express measurement uncertainty. It is especially applicable when the uncertainty is large (e.g. Read More

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An introduction to hand-held infra-red and Raman instrumentation.

Anal Methods 2020 Mar;12(11):1532-1535

The past 20 years have seen widening applications of hand-held instruments which facilitate operation outside the confines of a laboratory thereby enabling on-site and in situ analysis of test materials with limited or no test material preparation. Hand-held infra-red and Raman instrumentation is now available for a wide range of applications in fields such as manufacturing, environmental protection or security, enabling staff without chemical analysis training to provide rapid answers to specific questions. This Technical Brief aims to inform both analysts and less-technically aware users of the applications, capabilities and limitations associated with the use of this equipment. Read More

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A label-free fluorescent biosensor based on a catalyzed hairpin assembly for HIV DNA and lead detection.

Anal Methods 2021 May 11. Epub 2021 May 11.

College of Chemical Engineering, Sichuan University, Chengdu 610065, China.

Herein, a label-free fluorescent signal amplification system based on a catalyzed hairpin assembly (CHA) is reported. In this system, two hairpin probes, H1 and H2, were well-designed in which G-quadruplex sequences were integrated into H2. The CHA reaction was triggered by target/trigger DNA and G-quadruplex sequences were released, which can bind the fluorescent amyloid dye thioflavin T (ThT) to provide fluorescence signals. Read More

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The influence of different liquid environments on the atomic force microscopy detection of living bEnd.3 cells.

Anal Methods 2021 May 10. Epub 2021 May 10.

International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China. and Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun 130022, China and IRAC, JR3CN, University of Bedfordshire, Luton LU1 3JU, UK.

Atomic force microscopy (AFM) is one of the most important tools in the field of biomedical science, and it can be used to perform the high-resolution three-dimensional imaging of samples in liquid environments to obtain their physical properties (such as surface potentials and mechanical properties). The influence of the liquid environment on the image quality of the sample and the detection results cannot be ignored. In this work, quantitative imaging (QI) mode AFM imaging and mechanical detection were performed on mouse brain microvascular endothelial (bEnd. Read More

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growth of ZIF-8 on gold nanoparticles/magnetic carbon nanotubes for the electrochemical detection of bisphenol A.

Anal Methods 2021 May 10. Epub 2021 May 10.

College of Chemistry and Chemical Engineering, Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Central South University, Changsha 410083, China.

We herein report a facile and scalable strategy for the fabrication of a metal-organic framework (MOF) based composite by in situ growing ZIF-8 on gold nanoparticle (AuNP) loaded magnetic carbon nanotubes (mCNTs). AuNPs were firstly loaded on PEI (polyethylenimine) modified mCNTs by electrostatic forces, and then AuNPs/mCNTs were encapsulated into the ZIF-8 frame through in situ self-assembling of zinc ions and 2-methylimidazole. The morphology, spectroscopy and structural properties of the AuNP/mCNT@ZIF-8 nanocomposites were systematically characterized. Read More

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Fluorometric discrimination of tyrosine isomers based on the inner filter effect of chiral Au nanoparticles on MoS quantum dots.

Anal Methods 2021 May 10. Epub 2021 May 10.

Jiangsu Key Laboratory of Advanced Materials and Technology, Changzhou University, Changzhou 213164, China.

A fluorescent chiral sensor is proposed based on the inner filter effect (IFE) of chiral Au nanoparticles (AuNPs) on MoS2 quantum dots (MoS2 QDs), which can be used for the discrimination of the isomers of tyrosine (Tyr). l-Tyrosine (l-Tyr) can induce obvious agglomeration of the chiral AuNPs, leading to an attenuated IFE of the chiral AuNPs and greatly restored fluorescence of the MoS2 QDs, and thus the enantioselective recognition of the Tyr isomers can be achieved. Also, l-Tyr but not d-Tyr induced agglomeration of the chiral AuNPs is confirmed by the larger association constant between l-Tyr and the chiral sensor. Read More

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6-Aminopyridine-3-boronic acid functionalized magnetic nanoparticles for highly efficient enrichment of -diol-containing biomolecules.

Anal Methods 2021 May 10. Epub 2021 May 10.

College of Chemistry and Chemical Engineering, Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471022, P. R. China. and Department of Chemistry Bengbu Medical College, 233030, China.

Boronate affinity materials, as efficient sorbents for extraction, separation and enrichment of cis-diol-containing biomolecules, have attracted more and more attention in recent years. However, conventional boronate affinity materials require a basic binding pH (usually 8.5), which gives rise to not only inconvenience in operation but also the risk of degradation of labile compounds, and suffer from low binding affinity, which make the extraction of cis-diol-containing compounds of low concentration difficult or impossible. Read More

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Analysis of antioxidants in flos by online gradient extraction and HPLC-FRAP.

Anal Methods 2021 May 10. Epub 2021 May 10.

Dongguan HEC Cordyceps R&D Co., Ltd., Dongguan 523850, China. and Xiangnan University, Chenzhou 423000, China.

Chrysanthemum indici flos (CIF), a traditional functional beverage, has been used in China for thousands of years. However, research on the antioxidant properties and compounds in CIF is insufficient. In the current study, an online gradient extraction (OGE) coupled with a high performance liquid chromatography-ferric reducing antioxidant power (HPLC-FRAP) system for rapid identification of antioxidants in CIF was proposed. Read More

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Thermal desorption part 2: applications in analytical measurement.

Anal Methods 2021 May 7. Epub 2021 May 7.

The past 30 years have seen increasing availability of methods and equipment using thermal desorption for the measurement of airborne substances. These methods offer excellent sensitivity and are well-suited to automation and, in particular, diffusive sampling, a sampling technique which is both easier to use and less obtrusive than pumped sampling. With advances in equipment, thermal desorption is being used in an increasingly wide variety of applications. Read More

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Amine-functionalized carbon-fiber microelectrodes for enhanced ATP detection with fast-scan cyclic voltammetry.

Anal Methods 2021 May 7. Epub 2021 May 7.

Department of Chemistry, University of Cincinnati, 312 College Dr., 404 Crosley Tower, Cincinnati, OH 45221-0172, USA.

Here, we provide evidence that functionalizing the carbon-fiber surface with amines significantly improves direct electrochemical adenosine triphosphate (ATP) detection with fast-scan cyclic voltammetry (FSCV). ATP is an important extracellular signaling molecule throughout the body and can function as a neurotransmitter in the brain. Several methods have been developed over the years to monitor and quantitate ATP signaling in cells and tissues; however, many of them are limited in temporal resolution or are not capable of measuring ATP directly. Read More

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A lanthanide-based ratiometric fluorescent biosensor for the enzyme-free detection of organophosphorus pesticides.

Anal Methods 2021 May;13(17):2005-2010

Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100037, P. R. China and State Key Laboratory of Food Nutrition and Safety, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China.

Organophosphorus pesticides (OPs) residues have caused great concern as they cause great harm to public health. Herein, a ratiometric fluorescent sensing system was developed for the OPs detection with the merits of enzyme-free, simple operation, short-time and sensitivity. The change in the fluorescence signal in the sensing system was provided by guanine-rich DNA (G-DNA) and silver nanoparticles (AgNPs) with terbium ion (Tb3+) and dured. Read More

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High-sensitivity detection of two H7 subtypes of avian influenza viruses (AIVs) by immunochromatographic assay with highly chromatic red silica nanoparticles.

Anal Methods 2021 May 6. Epub 2021 May 6.

Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang, China.

In this work, a sensitive and quantitative immunochromatographic assay (ICA) detection method for avian influenza viruses (AIVs) of the H7 hemagglutinin (HA) antigen was established based on highly chromatic red silica nanoparticles (SiNPs). It can detect two H7 subtypes of influenza viruses, H7N2 and H7N9. The highly chromatic red SiNPs were prepared by adsorbing C. Read More

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Femtomolar determination of an ovarian cancer biomarker (miR-200a) in blood plasma using a label free electrochemical biosensor based on L-cysteine functionalized ZnS quantum dots.

Anal Methods 2021 May;13(17):2021-2029

Department of Chemistry, Faculty of Science, Yazd University, Yazd, 89195-741, Iran.

In the present study, a label-free electrochemical genosensor was designed based on ZnS quantum dots functionalized with l-cysteine (Cys-ZnS-QDs) to detect miR-200a, as a special ovarian cancer biomarker. The Cys-ZnS-QD genosensor was characterized by transmission electron microscopy (TEM), UV-Vis absorption and fluorescence methods. Cys-ZnS-QDs are electrodeposited on the glassy carbon electrode surface and act as a suitable substrate for immobilization of the DNA probe. Read More

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An improved PD-AsLS method for baseline estimation in EDXRF analysis.

Anal Methods 2021 May;13(17):2037-2043

Chengdu University of Technology, Chengdu, Sichuan 610000, China. and Applied Nuclear Techniques in Geosciences Key Laboratory of Sichuan Province, Chengdu, Sichuan 610000, China.

Baseline correction is an important step in energy-dispersive X-ray fluorescence analysis. The asymmetric least squares method (AsLS), adaptive iteratively reweighted penalized least squares method (airPLS), and asymmetrically reweighted penalized least squares method (arPLS) are widely used to automatically select the data points for the baseline. Considering the parametric sensitivity of the aforementioned methods and the statistical characteristics of the X-ray energy spectrum, this paper proposes an asymmetrically reweighted penalized least squares method based on the Poisson distribution (PD-AsLS) to automatically correct the baseline of X-ray spectra. Read More

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A substantial increase of analytical throughput in capillary electrophoresis throughput by separation-interrupted sequential injections.

Anal Methods 2021 May;13(17):1995-2004

Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and University of Chinese Academy of Sciences, Beijing 100049, China and Beijing National Laboratory for Molecular Sciences, Beijing 100190, China.

How to further improve the throughput of capillary electrophoresis (CE) is a fascinating question. Herein an idea to substantially increase the throughput of CE has been proposed together with theory and experimental demonstration. The key is to introduce samples for CE, one after another, by a short suspension of voltage application, which was hence termed separation-interrupted sequential injections (Sisi). Read More

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Supramolecular assembly induced chiral interface for electrochemical recognition of tryptophan enantiomers.

Anal Methods 2021 May;13(17):2011-2020

School of Chemistry, EaStCHEM, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh, EH93JJ, UK.

The β-CD@PEI-Fc chiral interface was prepared based on the supramolecular host-guest interaction between ferrocene (Fc) grafted polyethyleneimine (PEI-Fc) and chiral β-cyclodextrin (β-CD). SEM results show that β-CD@PEI-Fc interface has a regular spatial structure, which can effectively distinguish tryptophan (Trp) enantiomers. Under the optimal conditions, differential pulse voltammetry shows that the peak current ratio (Id/Il) of Trp enantiomers can reach 2. Read More

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2D bimetallic Ni/Fe MOF nanosheet composites as a peroxidase-like nanozyme for colorimetric assay of multiple targets.

Anal Methods 2021 May;13(17):2066-2074

Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.

In this contribution, 2D Ni/Fe MOF nanosheets were synthesized by a simple two-step ultrasound strategy at room temperature, i.e. the 2D Ni-MOF with a lamellar structure was first synthesized by the top-down ultrasonic assisted stripping route, followed by introducing Fe3+ ions as a metal node and terephthalic acid as an organic ligand to form 2D Ni/Fe MOF nanosheets that exhibited weak oxidase-like and strong peroxidase-like properties. Read More

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(Very) polar organic compounds in the Danube river basin: a non-target screening workflow and prioritization strategy for extracting highly confident features.

Anal Methods 2021 May 14;13(17):2044-2054. Epub 2021 Apr 14.

Technical University of Munich (Chair of Urban Water Systems Engineering), Garching, Germany.

Recently, more and more research has been focused on the analysis of polar organic compounds as they tend to be persistent and mobile in the aquatic environment. The serial coupling of reversed-phase and hydrophilic interaction liquid chromatography allows the separation of analytes of an extended polarity range within a single run. The non-target screening approach was driven by high-resolution mass spectrometry and is able to detect unexpected compounds. Read More

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A novel method for the rapid sensing of HO using a colorimetric AuNP probe and its DFT study.

Anal Methods 2021 May 15;13(17):2055-2065. Epub 2021 Apr 15.

Natural Product Chemistry Section, CSIR-North East Institute of Science and Technology. Branch Itanagar, Arunachal Pradesh 791110, India.

Hydrogen peroxide (HO) has tremendous applications in industry, medicine and in our day-to-day lives. It is toxic to human health upon exposure at a high concentration. Therefore, a green and cost-effective sensing technique is greatly needed for the sensitive naked eye detection of peroxide. Read More

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Design and development of a prototype for specific naked-eye detection of blister and nerve agents.

Vinod Kumar

Anal Methods 2021 May 6. Epub 2021 May 6.

Process and Technology Development Division, Defence Research & Development Establishment, Jhansi Road, Gwalior 474002, India.

In view of the strong need to strengthen the national security arising from chemical terrorism, a rapid, specific, and onsite detection of chemical warfare agents (CWAs) employing a simple and easy-to-use kit is of utmost importance. Constant and sincere efforts are being carried out by the scientific community to find reliable techniques/methods for early warning detection. Herein, we designed a prototype technique in the form of a smart and portable chemical weapon detection kit (CWDK) to facilitate rapid and onsite detection. Read More

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Rational design of a HA-AuNPs@AIED nanoassembly for activatable fluorescence detection of HAase and imaging in tumor cells.

Anal Methods 2021 May 14;13(17):2030-2036. Epub 2021 Apr 14.

Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, Hunan Provincial Key Lab of Advanced Materials for New Energy Storage and Conversion, Hunan Provincial Key Laboratory of Controllable Preparation and Functional Application of Fine Polymers, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China.

Aggregation induced emission (AIE) dots have gained broad attention in fluorescence bioimaging and biosensors in virtue of their distinctive optical properties of splendid biocompatibility, high brightness and good photostability. However, the application of AIE dots in sensing and imaging of enzymes in cells remains at an early stage and needs to be further explored. In this report, we proposed a novel AIE-dot-based nanoprobe for hyaluronidase (HAase) detection using a simple electrostatic self-assembly of AIE dots with gold nanoparticles functionalized using hyaluronic acid (HA-AuNPs), named HA-AuNPs@AIEDs. Read More

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Development of a RPLC-UV method for monitoring uncleaved HIV-1 envelope glycoprotein.

Anal Methods 2021 May 6. Epub 2021 May 6.

Vaccine Production Program, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Gaithersburg, MD 20878, USA.

One of the HIV-1 vaccine design efforts has focused on developing a recombinant HIV-1 trimeric envelope glycoprotein (Env) as an immunogen to induce broadly neutralizing antibodies. A native-like immunogen, the BG505.DS. Read More

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Anodic near-infrared electrochemiluminescence from Cu-doped CdTe quantum dots for tetracycline detection.

Anal Methods 2021 May 4. Epub 2021 May 4.

Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.

A sensitive anodic near-infrared electrochemiluminescence (ECL) immunosensor for the detection of tetracycline, based on Cu-doped CdTe quantum dots, was fabricated for the first time in this work. We have synthesized Cu-doped CdTe quantum dots by co-precipitation. The emission spectrum of the Cu-doped CdTe quantum dots could reach the near-infrared region at 730 nm in a short reflux time. Read More

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