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Fluoride detection has been playing an important role in chemical, biological, and medicinal field, especially for keeping physical health and resisting environmental pollution. Herein, a urolithin B fluorescent probe has been successfully developed with good sensitivity, selectivity, anti-interference ability. The low limit of detection (LOD) refers to 0.156 μM, and the instant response time to F− is less than 1 s. The probe is suitable for quantitatively and qualitatively ratiometric detection for F− in solution with two distinct emission bands at 425 (blue) and 566 nm (orange), with the coordinate change of CIE from (0.38, 0.41) to (0.22, 0.11). Urolithin B displayed a remarkable ratiometric fluorescence response towards F−. The detection mechanistic was further proposed by NMR and electronic spectroscopic experiments combining with time-dependent density functional theoretical calculation. [Display omitted] • A Ratiometric fluorescent probe was developed. • The photochemical properties and LOD of UB to F− were investigated. • Mechanism of UB sensing toward F− was confirmed by 1H NMR, DFT and TD-DFT calculation. • Response time less than second could be applied as an instant detection. • Coordination ratio for UB and F− was determined according to Job's plot. [ABSTRACT FROM AUTHOR]

More and more severe energy problem triggers extensive application of nuclear energy, and the adverse effects brought by nuclear materials such as uranyl to the environment are becoming the concern, as it has become a threat to human's health. Therefore, the detection of uranyl is increasingly important, which aims to make the application of uranium under surveillance and protection. A lot of detection methods employing varying materials based on different techniques for uranyl have been proposed including those using expensive and complicated instruments such as ICP-MS, ESI-MS, and neutron activation analysis etc. Those methods based on expensive instruments often provide quite low limit of detection (LOD) and excellent validity and repeatability, however, methods that are low-cost, convenient and rapid are in demand because these are satisfied characters for on-site and in-time determination. In the review, we discuss uranyl sensors based on spectrographic techniques, which is facile and promising for rapid assessment of uranium content in practical application. Spectrographic techniques including fluorescence, UV– vis spectrophotometry, resonance light scattering (RLS) and surface enhanced Raman scattering (SERS) are evaluated. In detail, the core materials that playing extremely important roles in detection performance are stated consisting of small molecule, biomolecule, polymer and nanomaterial. Image 1 • It is a guide for the status of uranyl sensors based on spectrophotometry methods. • Fluorescence, UV– vis , RLS and SERS for uranyl sensors are evaluated in detail. • Small molecule, biomolecule, polymer and nanomaterial are discussed for sensor. • It helps design and develop simple yet effective methods for practical application. [ABSTRACT FROM AUTHOR]

Surface Enhanced Raman Spectroscopy is increasingly used as a sensitive bioanalytical tool for detection of variety of analytes ranging from viruses and bacteria to cancer biomarkers and toxins, etc. This comprehensive review describes principles of operation and compares the performance of immunoassays and aptamer assays with Surface Enhanced Raman scattering (SERS) detection to each other and to some other bioassay methods, including ELISA and fluorescence assays. Both immuno- and aptamer-based assays are categorized into assay on solid substrates, assays with magnetic nanoparticles and assays in laminar flow or/and strip assays. The best performing and recent examples of assays in each category are described in the text and illustrated in the figures. The average performance, particularly, limit of detection (LOD) for each of those methods reflected in 9 tables of the manuscript and average LODs are calculated and compared. We found out that, on average, there is some advantage in terms of LOD for SERS immunoassays (0.5 pM median LOD of 88 papers) vs SERS aptamer-based assays (1.7 pM median LOD of 51 papers). We also tabulated and analyzed the clinical performance of SERS immune and aptamer assays, where selectivity, specificity, and accuracy are reported, we summarized the best examples. We also reviewed challenges to SERS bioassay performance and real-life application, including non-specific protein binding, nanoparticle aggregation, limited nanotag stability, sometimes, relatively long time to results, etc. The proposed solutions to those challenges are also discussed in the review. Overall, this review may be interesting not only to bioanalytical chemist, but to medical and life science researchers who are interested in improvement of bioanalyte detection and diagnostics. [Display omitted] • SERS immunoassays and SERS aptamer-based assays can achieve high sensitivity in detection of various bioanalytes. • The calculated median LOD for SERS immuno vs SERS aptamer assays is 0.5 pM vs 1.7 pM, from 88 & 51 references, respectively • The challenges to SERS bioassays include non-specific protein binding, NP agglomeration, , extended assay time, etc. • Ways to overcome the challenges: SAMs to minimize non-specific protein binding, rotating substrates, magnetic NPs, etc. [ABSTRACT FROM AUTHOR]

Poor recovery of phosphorus (P) across natural environment (water, soil, sediment, and biological sources) is causing rapid depletion of phosphate rocks and continuous accumulation of P in natural waters, resulting in deteriorated water quality and aquatic lives. Accurate detection and characterization of various P species using suitable analytical methods provide a comprehensive understanding of the biogeochemical cycle of P and thus help its proper management in the environment. This paper aims to provide a comprehensive review of the analytical methods used for P speciation in natural environment by dividing them into five broad categories (i.e., chemical, biological, molecular, staining microscopy, and sensors) and highlighting the suitability (i.e., targeted species, sample matrix), detection limit, advantages-limitations, and reference studies of all methods under each category. This can be useful in designing studies involving P detection and characterization across environmental matrices by providing insights about a wide range of analytical methods based on the end user application needs of individual studies. [Display omitted] • Analytical methods for P speciation in natural environment comprehensively reviewed. • Detectable species, sensitivity, specificity, and suitable sample matrix of each method discussed. • Advantages and limitations of each method reviewed. • Multiple relevant studies from each method summarized in tabular form. [ABSTRACT FROM AUTHOR]

In this work, polyaniline (PANI) synthesized by in-situ polymerization was mechanically mixed with different feeding mass ratios of Y 2 O 3 to form four Polyaniline/Yttrium oxide (PYO) composites. Among them, the PYO-4 composite acquiring nanorod structure with high aspect ratio confirmed from its TEM image and consequent maximum enhancement in its humidity sensing response discussed in comparison with those of PANI and other composites. The interaction of PANI with Y 2 O 3 in the composite confirmed from FTIR studies. The increase in defects and vacancies in all the composites, being maximum in PYO-4 composite nanorods compared to those of PANI confirmed from XRD studies. Maximum increase in the porosity of PYO-4 composite nanorods as compared to those of PANI and other composites confirmed from SEM studies. The humidity sensing studies revealed that, PYO-4 composite nanorods showed a maximum sensing response of 99.99% with a dynamic response and recovery time of 3 s and 4 s respectively. The PYO-4 composite nanorods having acquired comparatively good sensing characteristics such as low real sensitivity and limit of detection (LOD), negligible hysteresis, best linearity and perfect stability as against those of PANI and other composites established which were also correlated with the calculated physical parameters such as porosity, water content and degree of swelling. Image 1 • Mechanical mixing of Polyaniline (PANI) and Yttrium oxide (Y 2 O 3) yields high density nanorods. • The high aspect ratio of the PYO-4 composite nanorods confirmed from TEM studies. • The PYO-4 composite nanorods have reached the epitome sensing response of 99.99%. • The PYO-4 composite nanorods acquired a quick response and recovery timing of 3 s and 4 s. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is still being recognized today as an unmet medical need. Currently, there is no cure and early preclinical diagnostic assay available for AD. Therefore much attention is now being directed at the development of novel methods for quantitative determination of AD biomarkers in the cerebrospinal fluid (CSF). Here, we describe the liquid chromatography-tandem mass spectrometry method for determination of 5-hydroxytryptamine (SER), 5-hydroxyindoleacetic acid (5-HIAA), homovanilic acid (HVA), noradrenaline (NADR), adrenaline (ADR), dopamine (DA), glutamic acid (Glu), γ-aminobutyric acid (GABA), 3,4-dihydroxyphenylacetic acid (DOPAC) and histamine (HIS) in cerebrospinal fluid (CSF) from the rat model for human tauopathy. The benzoyl chloride was used as pre-column derivatization reagents. Neurotransmitters and metabolites were analysed on ultra performance liquid chromatography (UPLC) on C18 column in combination with tandem mass spectrometry. The method is simple, highly sensitive and showed excellent linearity with regression coefficients higher than 0.99. The accuracy was in a range of 93-113% for all analytes. The inter-day precision (n=5 days), expressed as %RSD, was in a range 2-10% for all analytes. Using this method we detected significant changes of CSF levels of two important neurotransmitters/metabolites, ADR and 5-HIAA, which correlates with progression of neurodegeneration in our animal model., (© 2013 Published by Elsevier B.V.)

A new approach of magnetic solid phase extraction (MSPE) coupled with graphite furnace atomic absorption spectrometry (GFAAS) has been developed for the speciation of Cr(III) and Cr(VI) using zincon-immobilized silica-coated magnetic Fe3O4 nanoparticles (Zincon-Si-MNPs) as the MSPE absorbent. Cr(III) was quantitatively reserved on the absorbent at pH 9.1 while total Cr was reserved at pH 6.5. The absorbed Cr species were eluted by using 2 mol/L HCl and detected by GFAAS. The concentration of Cr(VI) could be calculated by subtracting Cr(III) from total Cr. All the parameters affecting the separation and extraction efficiency of Cr species such as pH, extraction time, concentration and volume of eluent, sample volume and influence of co-existing ions were systematically examined and the optimized conditions were established accordingly. The detection limit (LOD) of the method was 0.016 and 0.011 ng mL(-1) for Cr(III) and Cr(VI), respectively, with the enrichment factor of 100 and 150. The precisions of this method (Relative standard deviation, RSD, n=7) for Cr(III) and Cr(VI) at 0.1 ng mL(-1) were 6.0% and 6.2%, respectively. In order to validate the proposed method, a certified reference material of environmental water was analyzed, and the result of Cr speciation was in good agreement with the certified value. This MSPE-GFAAS method has been successfully applied for the speciation of Cr(III) and Cr(VI) in lake and tap waters with the recoveries of 88-109% for the spiked samples. Moreover, the MSPE separation mechanism of Cr(III) and Cr(VI) based on their adsorption-desorption on Zincon-Si-MNPs has been explained through various spectroscopic characterization., (© 2013 Elsevier B.V. All rights reserved.)

A facile chiral ligand exchange capillary electrophoresis (CLE-CE) system with Zn(II)-L-alanine as the chiral selector in the presence of β-cyclodextrin has been developed for enantioseparation of dansyl amino acids. The influence of the key factors, such as buffer pH, the ratio of Zn (II) to ligand, the concentration of β-cyclodextrin and the concentration of the complex, were investigated in detail when D, L-Tyr and D, L-Thr were selected as the model analytes. The proposed method showed favorable quantitative analysis property of dansyl D, L-tyrosine with good linearity (r(2)≥0.999) and reproducibility (RSD≤3.8%), then, it was applied in studying the activity of tyrosinase through the determination of L-tyrosine concentration variation after being incubated with the enzyme. Further, the inhibitory efficiency of kojic acid and soy sauce on the tyrosinase was investigated. The IC50 of kojic acid obtained from the sigmoidal inhibitory curve was 21.35 μM. The results imply that the proposed CLE-CE system has the potential in exploring the activity of enzyme and screening the inhibitors of enzyme., (© 2013 Elsevier B.V. All rights reserved.)

This study focuses on the development of an analytical method based on headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of 76 micropollutants in water samples. The selected micropollutants include volatile organic compounds (VOCs) (e.g. chlorobenzenes, chloroalkanes), endocrine disrupting compounds (EDCs) (e.g. bisphenol A and tributyl phosphate), odour compounds (e.g. limonene, phenol), fragrance allergens (e.g. geraniol, eugenol) and some pesticides (e.g. heptachlor, terbutryn). The experimental conditions affecting their extraction, such as the type of fibre, temperature and time of extraction, sample volume and ionic strength of the samples were optimized using HS-SPME. The method showed good linear range, reproducibility between days, repeatability and low detection limits (at ng L(-1) levels). The validated method has been applied to determine the target organic micropollutants in aqueous samples from different experimental research units of surface water, sea water, waste water and those effluents of advance membrane treatments. The optimized method showed good performance in the different types of samples studied. The analysis revealed the presence of several micropollutants at concentrations between 20 and 5000 μg L(-1), such as ethylbenzene, o-xylene, p-isopropilbenzene, D-limonene, citral and isoeugenol, due to the fact that these species are commonly used in domestic and industrial applications., (© 2013 Elsevier B.V. All rights reserved.)

There are virtually no analytical methods that describe determination of vinblastine and other vinca alkaloids in tumour tissue, albeit quantitative data on tumour drug amount is essential for maximal benefit of a particular anticancer treatment. The analytical method presented herein uses state-of-the-art sample preparation, separation and detection techniques to allow sensitive and selective determination of vinblastine in tumour tissue. After cryogenic grinding and sonication, tumour suspensions were extracted by Oasis MAX solid phase extraction and analysed for vinblastine with ultra-high performance liquid chromatography coupled to positive electrospray ionisation-high resolution mass spectrometric detection. The developed analytical method quantifies vinblastine down to 23 ng/g tumour tissue and shows satisfactory linearity (r(2)>0.99), precision (1.1-8.2%), accuracy (98%) and high selectivity with almost complete absence of matrix effects. The proposed method was found suitable to follow vinblastine levels in mice tumours and could be used to support preclinical pharmacologic studies., (© 2013 Elsevier B.V. All rights reserved.)

Arsenic is an element widely present in nature. Additionally, it may be found as different species in several matrices and therefore it is one of the target elements in chemical speciation. Although the number of studies in terrestrial plants is low, compared to matrices such as fish or urine, this number is raising due to the fact that this type of matrix are closely related to the human food chain. In speciation analysis, sample preparation is a critical step and several extraction procedures present drawbacks. In this review, papers dealing with extraction procedures, analytical methods, and studies of species conservation in plants cultivated in terrestrial environment are critically discussed. Analytical procedures based on extractions using water or diluted acid solutions associated with HPLC-ICP-MS are good alternatives, owing to their versatility and sensitivity, even though less expensive strategies are shown as feasible choices., (© 2013 Elsevier B.V. All rights reserved.)

Chlorophenols (CPs) as persistent toxic compounds are of worldwide environmental concern. Usage of chlorinated phenols, especially pentachlorophenol (PCP), has been restricted or widely banned in many countries due to their possible adverse health effects even at low concentrations. Ion mobility spectrometry (IMS) has received increasing interest in environmental applications due to its unique characteristics, such as portability and speed of analysis. A range of sample introduction methods combined with IMS enable analysis from different environmental matrices. This study utilised headspace solid phase microextraction IMS (HS-SPME-IMS) in the determination of CPs from water samples. The extraction conditions were examined and the method was applied to real water samples. The developed method is suitable to detect CPs at milligram per liter level in water. Based on the results, SPME-IMS setup is feasible as an early warning system for water monitoring of pollutants present in drinking or surface water in case of environmental accidents or leakages., (Copyright © 2013 Elsevier B.V. All rights reserved.)