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In this study we have developed a new aptasensor for cadmium (Cd 2+ ) detection in water. Gold electrode surface has been chemically modified by electrochemical reduction of diazonium salt (CMA) with carboxylic acid outward from the surface. This was used for amino-modified cadmium aptamer immobilization through carbodiimide reaction. Chemical surface modification was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This latter was also used for Cd 2+ detection. The aptasensor has exhibited a good linear relationship between the logarithm of the Cd 2+ concentration and the impedance changes in the range from 10 -3 to 10 -9  M with a correlation R 2 of 0.9954. A high sensitivity was obtained with a low limit of detection (LOD) of 2.75*10 -10  M. Moreover, the developed aptasensor showed a high selectivity towards Cd 2+ when compared to other interferences such as Hg 2+ , Pb 2+ and Zn 2+ . The developed aptasensor presents a simple and sensitive approach for Cd 2+ detection in aqueous solutions with application for trace Cd 2+ detection in spring water samples., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Environmental monitoring is one of the most dynamically developing branches of chemical analysis. In this area, the use of multidimensional techniques and methods is encouraged to allow reliable determinations of metal ions with portable equipment for in-field applications. In this regard, this study presents, for the first time, the capabilities of a polymer inclusion membrane (PIM) sensor to perform cadmium (II) determination in aqueous solutions by in situ visible (VIS) and Mid- Fourier transform infrared spectroscopy (MID-FTIR) analyses of the polymeric films, using a partial least squares (PLS) chemometric approach. The influence of pH and metal content on cadmium (II) extraction, the characterization of its extraction in terms of the adsorption isotherm, enrichment factor and extraction equilibrium were studied. The PLS chemometric algorithm was applied to the spectral data to establish the relationship between cadmium (II) content in the membrane and the absorption spectra. Furthermore, the developed MID-FTIR method was validated through the determination of the figures of merit (accuracy, linearity, sensitivity, analytical sensitivity, minimum discernible concentration difference, mean selectivity, and limits of detection and quantitation). Results showed reliable calibration curves denoting systems' potentiality. Comparable results were obtained in the analysis of real samples (tap, bottle, and pier water) between the new MID-FTIR-PLS PIM based-sensor and F-AAS.

Silver ions (Ag+) have been proposed as a biocide to treat the water in NASA's next generation of human space exploration vehicles/habitats. One advantage of Ag+ is that it is effective as a biocide in a range (200 to 500 ppb) safe for human consumption. So, monitoring Ag+ is essential to ensure the safety and health of the crew. Here we present two analytical methods based on capillary electrophoresis and capacitively coupled contactless conductivity detection (CE-C4D) to address the need to monitor Ag+ levels in water. Using 5 M acetic acid as a background electrolyte (BGE), 100 ppb of Ag+ could be detected in a simulant of the International Space Station (ISS) water. In addition to Ag+, other inorganic cations (K+, Ca2+, Na+, Mg2+, Ni2+, and Zn2+) frequently found in the ISS potable water can be detected simultaneously using this BGE in less than 4.5 min. By using a BGE composed of 0.5 M acetic acid, levels of Ag+ as low as 25 ppb could be detected in the ISS water simulant in less than 2.5 min. Although in this condition none of the other cations interfered with the detection of Ag+, some of them co-migrated, which could prevent obtaining additional information about the sample composition.

Water exchange between bulk water and water-ion complexes will be at equilibrium when the charge density of the complex surface equals the charge density of bulk water, producing a constant radius water-ion complex. This complex will migrate in an electric field at a velocity proportional to the complex radius. CE velocity is the sum of the complex charge-dependent velocity and the buffer electro-osmotic flow. Simultaneous use of both a base (1.07 mM imidazole) and an acid (1.5 mM MOPS) buffer negates EOF at pH 7.4. Electric fields below 300 V/cm (potassium, calcium) and 400 V/cm (magnesium) yield migration velocities with no dehydration of the water-ion complexes. The number of waters per complex increase with the ion charge density: K + 1.90, Ca ++ 5.90, Mg ++ 6.59 waters/ion. The charge densities of the complexes are similar: K + 1.24, Ca ++ 1.43, Mg ++ 1.21 e/nm 2 , for an average bulk water charge density of 1.29 ± 0.11 (SD) e/nm 2 . The addition of 0.1% Triton increases the number of waters for Mg ++ to 25.33 and lowers the charge density to 0.497 e/nm 2 . High electric field dehydration shows that calcium will be fully dehydrated at 638.3 V/cm and magnesium fully dehydrated at 925.5 V/cm, which occur at 6.15 and 5.78 nm from the membrane. Dehydrated magnesium will then bind to calcium channels leading to decreased smooth muscle activation., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The abuse of tetracycline arises the risk of antibiotic resistance genes and has been paid much attention. To understand the potential bioavailability of tetracycline (TC) in soil environments, this study explored the behaviors of TC adsorbing to six types of soils sampled from different regions of China. Moreover, the solution pH and existence of Cd 2+ effect on TC sorption to soils were investigated to understand the influential factors affecting TC sorption. The results showed that the soil properties and sorption capacity of TC varied significantly with different soils. The sorption capacity of TC to soils might be largely affected by cation exchange capacity (CEC) and soil organic carbon (SOC), while the sorption rate, interaction strength and equilibrium sorption binding might be affected by soil pH, pH PZC , soil inorganic carbon (SIC) and H content. The result of solution pH effect suggested that the predominant sorption mechanism for acid soils might be hydrophobic interactions between soils and H 2 TC 0 , and the cation exchange was possibly proposed as the primary mechanism for TC sorption to alkaline soils. Furthermore, the presence of Cd 2+ might increase TC sorption to acid soil, while reduce TC sorption to alkaline soil. It is expected that this study may provide important information for predicting the potential fate of TC (or similar antibiotics) in different soils, and thus helping to assess the bioavailability of TC in soils., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In this work, lignin fractionation is proposed as an effective approach to reduce the heterogeneity of lignin and improve the adsorption and recycle performances of lignin as a cationic dye adsorbent. By stepwise dissolution of enzymatic hydrolysis lignin in 95% and 80% ethanol solutions, three lignin subdivisions (95% ethanol-soluble subdivision, 80% ethanol-soluble subdivision, and 80% ethanol-insoluble subdivision) were obtained. The three lignin subdivisions were characterized by gel permeation chromatography (GPC), FTIR, 2D-NMR and scanning electron microscopy (SEM), and their adsorption capacities for methylene blue were compared. The results showed that the 80% ethanol-insoluble subdivision exhibited the highest adsorption capacity and its value (396.85 mg/g) was over 0.4 times higher than that of the unfractionated lignin (281.54 mg/g). The increased adsorption capacity was caused by the enhancement of both specific surface area and negative Zeta potential. The maximum monolayer adsorption capacity of 80% ethanol-insoluble subdivision by adsorption kinetics and isotherm studies was found to be 431.1 mg/g, which was much higher than most of reported lignin-based adsorbents. Moreover, the 80% ethanol-insoluble subdivision had much higher regeneration yield (over 90% after 5 recycles) compared with the other two subdivisions. Consequently, the proposed fractionation method is proved to be a novel and efficient non-chemical modification approach that significantly improves adsorption capacity and recyclability of lignin.

The study investigates transformation mechanism of ions on different waters in Alpine region through analyzed the hydrochemical characteristics of the major ions of precipitation, glacier and snow meltwater, supra-permafrost water and river water in permafrost regions in the Tibetan Plateau under climate warming. The results showed that, The relation between recharge and discharge was the major ways for ionic transformation of each water body. Precipitation and glacier and snow meltwater are the main input sources for ionic transformation, and river water is the final output source. Different water bodies had different ionic concentrations and different hydrochemical types. However, different water bodies in different months (from June to September) also had different hydrochemical types. The water - rock interaction, reactions for ions, dilution effect and other effect for ions played an important role in the process of ion transformation. The increasing of temperature would lead to the accelerated melting of glaciers, permafrost and snow in the alpine regions, so the amount of supra-permafrost water and glacier and snow meltwater will increase, which leads to the increase of runoff. Meanwhile, the increase of temperature makes evaporation stronger. The strong of evaporation will accelerate the transformation of liquid water to gaseous water. Moreover, ion translation and water conversion are synchronous. Accordingly, ions are also accelerating transformation in the process of accelerated transformation of water body. Climate change is not only the main driving force for multiphase water transformation, but also the main driving force for the ion transformation of various water bodies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Noncovalent complexes between cyclodextrin (CD) and divalent metal cations drew growing attentions due to their applications in the pharmaceutical industry for molecular recognition. In this study, gas-phase binding of noncovalent complexes between α-, or γ-CD and divalent metal cations was investigated by electrospray ionization mass spectrometry (ESI-MS), demonstrating the formation of 1:1 stoichiometric noncovalent complexes. The binding of the complexes were furtherly confirmed by collision-induced dissociation (CID) with tandem mass spectrometry. The CID revealed the fragmentation pattern were strongly dependent on the electronic configuration of the cations and the charge separation reaction frequently took place in the cyclodextrin-complexes with transition metal cations. For the non-covalent complexes of α-CD with Mg 2+ , Ca 2+ , Sr 2+ or Ba 2+ at a collision energy of 25 eV, the fragments attributed to [α-CD + cation-nGlucose unit] 2+ were observed (named series A). However, for the γ-CD complexes with transition metal cations Co 2+ , Ni 2+ , Cu 2+ or Zn 2+ , apart from fragments of series A, it were observed fragment ions of [γ-CD + cation-nGlucose unit] + (named series B), together with the Glucose unit (m/z 163.2) and its products with loss of H 2 O (m/z 145.2 and 126.8). The CID performed at a collision energy from 10 to 50 eV showed that the binding strength of complexes increase in the order of [α-CD + Mg] 2+ , [α-CD + Ca] 2+ , [α-CD + Sr] 2+ and [α-CD + Ba] 2+ . Through mass spectrometric titrations, the values of dissociation constant K d (in μmol•L -1 ) for the complexes of α-CD with Ca 2+ or Ni 2+ were obtained, which were 4.30 and 4.26, respectively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Laser-induced breakdown spectroscopy, coupled with advanced chemometric methods, was used to quantitate multiple elements in a seaweed-based fertilizer. The influence of important parameters was determined using partial least squares regression (PLSR), support vector regression (SVR) and random forest (RF) optimizations. Optimal results for Mg, K and P were obtained using PLSR, whereas RF yielded the best results for Mn, Cu, Sr and Ca. The best predictions for Ba levels were obtained with SVR. The lowest root mean square errors in the prediction sets for Mn, Cu, Sr, Ba, Mg, K, P and Ca were 48.27 µg/g, 36.90 µg/g, 0.37 mg/g, 40.32 µg/g, 1.99 mg/g, 2.03 mg/g, 4.81 mg/g and 14.08 mg/g, respectively, with average relative standard deviations of 13.65%, 2.68%, 19.80%, 5.17%, 3.32%, 2.98%, 1.82% and 5.81%. The results showed that the optimal multivariate model depended on the specific element being analyzed. The proposed method provides a rapid means of determining multielement concentrations in seaweed-based fertilizers.

The Opuntia ficus indica (L.) (OFI) is used as a nutritional and pharmaceutical agent in various dietary and value added products. This study underlines the possible use of native prickly pear cladode powder as a functional ingredient for health-promoting food production. To summarise, chemical characterization of polyphenols, minerals and soluble dietary fibre was performed; furthermore, the antioxidant activity and bioaccessibility of polyphenols and minerals were assessed. Eleven compounds between phenolic acids and flavonoids were identified, with piscidic acid and isorhamnetin derivatives being the most abundant. Opuntia's dietary fibre was mainly constituted of mucilage and pectin, and was composed of arabinose, galactose, glucose, mannose, rhamnose, and xylose sugars. The polyphenols' bioaccessibility was very high: piscidic acid at 200%, eucomic and ferulic acids >110% and flavonoids from 89% to 100%. The prickly pear cladode powder is also a source of minerals, as cations (calcium, sodium, potassium and magnesium) and anions (sulphate and chloride), with high magnesium bioaccessibilty (93%). OFI powder showed good capacity of radical scavenging measured by DPPH and ABTS methods, with 740 and 775 μmol Trolox/100 g OFI, respectively. Finally, the presented results allow the consideration of this natural product as a source of several essential nutrients, with a possible use in the food industry as a functional ingredient.

We have studied the dissociation of the trifluoromethane molecule, CHF 3 , into negative ionic fragments at the C 1s and F 1s edges. The measurements were performed by detecting coincidences between negative and positive ions. We observed five different negative ions: F - , H - , C - , CF - , and F 2 - . Their production was confirmed by the analysis of triple coincidence events (negative-ion/positive-ion/positive-ion or NIPIPI coincidences) that were recorded with cleaner signals than those of the negative-ion/positive-ion coincidences. The intensities of the most intense NIPIPI coincidence channels were recorded as a function of photon energy across the C 1s and F 1s excitations and ionization thresholds. We also observed dissociation channels involving the formation of one negative ion and three positive ions. Our results demonstrate that negative-ion/positive-ion coincidence spectroscopy is a very sensitive method to observe anions, which at inner-shell edges are up to three orders of magnitude less probable dissociation products than cations., (© 2019 John Wiley & Sons, Ltd.)

This review focuses on cationic starches with a low degree of substitution (<0.06) which are mainly used for production of paper-based products. After a brief introduction on starch in general, cationization pathways and importance of cationic starches in paper production, this review emphasizes on the analytical challenges from different perspectives. These include the different length scales of starches when in solution: the macromolecular level, their assembly into nm aggregates and finally hydrocolloids with hundreds of nanometers of diameter. We give an overview on the current state of the art on the analysis of such challenging samples and aim at providing a guideline for obtaining and presenting reliable analytical data., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Four rhodamine-based fluorescent probes M1-M4 were synthesized in one step using Mannich reaction. The Mannich reaction based approach has the advantages of simplicity, good yield and excellent atomic economy. The structures were determined by 1 H NMR, 13 C NMR, IR and HRMS. The probe M3 as a representative compound was characterized by single-crystal X-ray analyses. The fluorescence and absorbance spectra research of the probes demonstrated that they could be used as Fe 3+ -selective fluorescent probes with good sensitivity, excellent linearity, and outstanding anti-interference in acetonitrile/Tris-HCl buffer solution (3:7, V/V; pH = 7.4). Moreover, confocal laser scanning microscopy experiments have proven that the probe M3 was successfully used for fluorescence imaging in MCF-7 cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

4,5-Bis(phtalimidomethyl)acridine (L) was studied as a chemosensor for metal ions in alcoholic matrices and showed to be selective for Al 3+ , through a linear fluorescence enhancement of 230% in the concentration range of 10-70 μmol L -1 . Benesi-Hildebrand and Job's formalisms indicated the formation of a 1:1 (Al 3+ :L) complex with a binding constant of 6.30 × 10 3 L mol -1 . DFT/TDDFT calculations allowed access to the energies of frontier orbitals and could explain the fluorescence augmentation upon complex formation, due to the restraining of PET process. Limit of detection and limit of quantification (R 2  = 0.998, least squares method) are 1.130 and 3.768 μmol L -1 , respectively, and validation was verified based on the variation of several analytical conditions. Practical application in spiked Brazilian sugarcane spirit showed recovery of (84 ± 0.42)% with no effect of interfering ions., Competing Interests: Declaration of competing interest We declare that there is no conflict of interest regarding this manuscript., (Copyright © 2020 Elsevier B.V. All rights reserved.)

New pyrazole bearing imidazole derivative was successfully synthesized and thoroughly characterized by various spectroanalytical techniques. The sensor DIBI shows a highly selective and sensitive fluorescent response with the addition of Al 3+ /Fe 3+ ions in acetonitrile-water mixture. The strong fluorescent molecule exhibits a notable ratiometric emissions at 462 nm and 470 nm for Al 3+ and Fe 3+ ions, respectively (λ ex  = 280 nm). Job's plot studies conclude that the coordination between DIBI with Al 3+ /Fe 3+ was 1:1 binding stoichiometry. The limit of detection of DIBI with Al 3+ /Fe 3+ was calculated as 2.12 × 10 -7  M and 1.73 × 10 -6  M, respectively. The TD-DFT calculations further supported the photonics performances of the free probe and its complexes. The reversibility and reusability of the sensor molecule are studied using EDTA. The probe was used to track Al 3+ /Fe 3+ in cancer cells via fluorescence microscopy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Nanomaterials with enzyme-like characteristics (also called nanozymes) have attracted increasing attention in the area of analytical chemistry. Nevertheless, most of the nanozymes used for analytical applications are oxidoreductase mimics, and their enzyme-like activities are usually demonstrated by using chromogenic and/or fluorogenic substrates. Herein, the phosphatase mimetic activity of cerium oxide nanoparticles (nanoceria) was investigated by using CDP-star as the chemiluminescent (CL) substrate. Interestingly, we found that the phosphatase mimetic activity of nanoceria can be remarkably inhibited by the addition of Al 3+ . Based on this finding, a highly sensitive and selective CL method for Al 3+ detection is proposed. The CL intensity of the nanoceria/CDP-star system decreased with the increasing Al 3+ concentrations in the range from 30 nM to 3.5 μM. A detection limit as low as 10 nM was obtained. Finally, the CL detection of intracellular Al 3+ was achieved, demonstrating the utility of the CL method in complex biological samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A novel method was developed for the simultaneous determination of inorganic anions (Cl - , SO 4 2- and ClO 3 - ) and cations (K + , Ca 2+ , Na + , Mg 2+ and Li + ) in wine by capillary electrophoresis-indirect ultraviolet detection (CE-UV) with dual-opposite end injection using 1-ethyl-3-methylimidazolium p -toluenesulfonate ([EMIm]TS) as the background electrolyte.[EMIm]TS acted as the running electrolyte and probe, generating the background signals for cations and anions under indirect UV light, consequently simplifying the electrophoretic medium. Under the optimal experimental conditions, baseline separation was achieved for the eight inorganic ions within 6.5 min. The linear ranges of the eight inorganic ions were 0.005-0.7 g/L, with correlation coefficients ( R 2 ) of 0.963-0.995. The limits of detection (LODs) were between 1.2 and 12.5 mg/L at a signal-to-noise ratio of 3 ( S/N =3). Eight inorganic ions were detected in three different brands of wines obtained from supermarket. Good recoveries of 90.1%-110.5% at three spiked levels (0.05, 0.2 and 0.4 g/L) were achieved with a low relative standard deviations (RSDs) ( n =5) of 1.1%-4.8%. The proposed method is robust and reliable for the sensitive and rapid analysis of the inorganic anions and cations, and it has potential in evaluating the quality of wine.

It's of vital importance to detect heavy metals in environment and living cells. In this work, four near-infrared regions boron dipyrromethene (BODIPY) probes (QBPH, PBPH, QBP and PBP) are constructed based on two BODIPY precursors (QB, PB) for sensing of Fe 3+ . As expected, these four probes exhibit obvious colorimetric and ratiometric response to Fe 3+ . In addition, QBP and PBP display highly sensitive and selective performance for detection of Fe 3+ . More importantly, QBP and PBP are successfully applied to near infrared imaging and detection of Fe 3+ in living A549 cells; it indicates that these novel designed probes could be a useful tool for the studies of Fe 3+ in living cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The formation and radical-directed dissociation of multiple hydrogen-abstracted peptide cations [M + H - mH]· + has been reported using MALDI-ISD with dinitro-substituted matrices. The MALDI-ISD of synthetic peptides using 3,5-dinitrosalicylic acid (3,5-DNSA) and 3,4-dinitrobenzoic acid (3,4-DNBA) as matrices resulted in multiple hydrogen abstraction from the analyte [M + H] + and fragment [ a ] + ions, i.e., [M + H - m H] + and [ a - m H] + ( m = 1-8). All of the ISD spectra showed unusually intense [ a ] + ions originating from cleavage at the Cα-C bond of the Leu-Xxx residues when peptides without Phe/Tyr/His/Cys residues were used. The intensity of the [ a n ] + series ions generated using 3,5-DNSA and 3,4-DNBA rapidly decreased with increasing residue number n , suggesting cleavage at multiradical sites of [M + H - m H] •+ . It was suggested that multiple hydrogen abstraction from protonated peptides [M + H] + mainly takes place from the backbone amide nitrogen.

Imaging mass spectrometry (IMS) is becoming an essential technique in lipidomics. Still, many questions remain open, precluding it from achieving its full potential. Among them, identification of species directly from the tissue is of paramount importance. However, it is not an easy task, due to the abundance and variety of lipid species, their numerous fragmentation pathways, and the formation of a significant number of adducts, both with the matrix and with the cations present in the tissue. Here, we explore the fragmentation pathways of 17 lipid classes, demonstrating that in-source fragmentation hampers identification of some lipid species. Then, we analyze what type of adducts each class is more prone to form. Finally, we use that information together with data from on-tissue MS/MS and MS 3 to refine the peak assignment in a real experiment over sections of human nevi, to demonstrate that statistical analysis of the data is significantly more robust if unwanted peaks due to fragmentation, matrix, and other species that only introduce noise in the analysis are excluded.

Understanding factors influencing groundwater quality is critical to the development of best management practices at the large watershed scale. In this study, the shallow groundwater (10-20 m depth) in the Su-Xi-Chang region, eastern China, was investigated as part of a monitoring program from 2007 to 2008 to analyze the regional groundwater quality as well as the hydrogeochemical processes and their controlling factors. Conventional physicochemical water parameters (pH, turbidity, electrical conductivity, dissolved oxygen, total phosphorus), major cations (Na + , Ca 2+ , Mg 2+ and NH 4 + ) and anions (Cl - , NO 3 - and SO 4 2- ) were measured. Hydrochemical methods and multivariate statistical methods were applied to analyze the hydrogeochemical signatures, origins, the similarities among the variables and to identify the main pollution sources in the groundwater. The results showed that (1) the concentrations of TDS (224.89-1086.70 mg/L) and turbidity (0.1-18.60 NTU) were higher than the class II groundwater quality standards in China and the WHO drinking water standards, (2) there were extremely high concentrations of ammonia (0.01-32.90 mg/L), with a mean value of 0.72 mg/L and (3) the nitrate concentrations (average value of 22.07 mg/L) exceeded the class III groundwater quality standards. The study also provided evidence that weathering, dissolution of carbonate, halite and silicate and cation exchange were the possible primary hydrogeochemical control mechanisms in the groundwater. The sources of ammonia, total phosphorus, sulfates and nitrates included rock-water interactions and anthropogenic activities. The groundwater administration of pollution sinks and sources, long-term legal frameworks and economic incentives should be improved to optimize watershed scale management in the context of rapid development in China.

A highly sensitive and selective indole-based probe IHT exhibited obvious color change from colorless to violet easily detected by naked eye as well as 'turn on' fluorescence response to Cu 2+ ion at physiological pH condition. The detection limit was determined to be as low as 8.93 × 10 -8  M, which was much lower than drinking water permission concentrations by the United States Environmental Protection Agency. The 1:2 binding mechanism was well confirmed by fluorescence titration, Job's plot, HRMS, IR analysis and DFT calculations. Furthermore, the probe IHT was successfully used for fluorescence imaging of Cu 2+ ion in living cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, we designed a novel Schiff-base probe from the condensation reaction of 3,5-diiodosalicylaldehyde with isoniazid. Treatment of the sensor molecule with different metal ions like K + , Ba 2+ , Ca 2+ , Mg 2+ , Fe 2+ , Mn 2+ , Co 2+ , Cu 2+ , Cd 2+ , Ni 2+ , Hg 2+ , Zn 2+ , Pb 2+ and Al 3+ in visual inspection and absorption measurements explained its colorimetric sensing ability. The sensor DISN displays a remarkable color variation from pale yellow to brownish-orange towards Co 2+ ion. The absorption and emission spectra of DISN, upon treating with various anions including F - , Br - , Cl - , I - , HSO 4 - , NO 3 - , H 2 PO 4 - , and CN - were tested. The addition of the fluoride ion to the receptor caused not only the intense color variation from pale yellow to orange but also a significant fluorescence turn-on response. Job's plot method fixed the binding of Co 2+ and F - to DISN separately, in 2:1 and 1:1 binding stoichiometry, respectively. The detection limit of 1.24 × 10 -7  M and 0.108 × 10 -6  M was attained for Co 2+ and F - , respectively. The TD-DFT calculations further supported the photophysical properties involved in the free probe and its complexes. The YES and INHIBIT logic function was found to operate from modulation in the absorbance and fluorescence behavior of Co 2+ and F - ions with DISN. Furthermore, DISN displays its practical applicability in filter-paper strips, live cell imaging, and real sample analyses., (Copyright © 2019. Published by Elsevier B.V.)

The detection of heavy metals such as Hg 2+ and Ag + is important and urgent. In this work, - NO 2 /- NH 2 /C=S boron dipyrromethene small molecular derivatives were synthesized at first. Then they were incorporated into polymer chains. The macromolecular fluorescent probes were obtained via Sonogashira reaction using the small molecular probes as building blocks. The as-prepared small-molecule fluorescent probe BO3 exhibits high sensing performance for Hg 2+ . By introducing it into macromolecules, the sensing ability still remains, and even more, the recognition performance is improved. The macromolecular fluorescent probes P1, P2, and P3 also have high recognition ability for Ag + with a binding ratio of 2:1 (metal ion to probe ratio). Through the study of the sensing mechanism and the recycling experiments, it is found that the probes responded by the photo-induced electron transfer mechanism and can be recycled and reused. At the same time, BO3, P2, and P3 show excellent recognition performance for Hg 2+ in living cells and zebrafish. Living cell imaging experiments indicated that these fluorescent probes had good cell membrane permeability and low cytotoxicity, and could realize bioimaging of Hg 2+ . Therefore, the application value of these fluorescent probes could be enlarged. Graphical abstract.

The quantitative analysis of tear analytes in point-of-care settings can enable early diagnosis of ocular diseases. Here, a fluorescent scleral lens sensor is developed to quantitatively measure physiological levels of pH, Na + , K + , Ca 2+ , Mg 2+ , and Zn 2+ ions. Benzenedicarboxylic acid, a pH probe, displays a sensitivity of 0.12 pH units within pH 7.0-8.0. Crown ether derivatives exhibit selectivity to Na + and K + ions within detection ranges of 0-100 and 0-50 mmol L -1 , and selectivities of 15.6 and 8.1 mmol L -1 , respectively. A 1,2 bis(o-aminophenoxy)ethane-N,N,-N',N'-tetraacetic-acid-based probe allows Ca 2+ ion sensing with 0.02-0.05 mmol L -1 sensitivity within 0.50-1.25 mmol L -1 detection range. 5-Oxazolecarboxylic acid senses Mg 2+ ions, exhibiting a sensitivity of 0.10-0.44 mmol L -1 within the range of 0.5-0.8 mmol L -1 . The N-(2-methoxyphenyl)iminodiacetate Zn 2+ ion sensor has a sensitivity of 1 µmol L -1 within the range of 10-20 µmol L -1 . The fluorescent sensors are subsequently multiplexed in the concavities of an engraved scleral lens. A handheld ophthalmic readout device comprising light-emitting diodes (LEDs) and bandpass filters is fabricated to excite as well as read the scleral sensor. A smartphone camera application and an user interface are developed to deliver quantitative measurements with data deconvolution. The ophthalmic system enables the assessment of dry eye severity stages and the differentiation of its subtypes., (© 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

By adjusting carboxylates, six Cd(ii) coordination polymers based on a naphthalene-methylene mixed-bridged-amide ligand, [Cd(L)(DNBA)2] (1), [Cd2(L)2(BDC)2(H2O)2]·2H2O (2), [Cd(L)(1,4-CHDA)] (3), [Cd(L)(HIPA)(H2O)]·H2O (4), [Cd(L)(MIP)]·H2O (5), and [Cd(L)(PMA)0.5(H2O)]·H2O (6) [L = N,N'-bis(4-methylenepyridin-4-yl)-1,4-naphthalene dicarboxamide, HDNBA = 3,5-dinitrobenzoic acid, H2BDC = 1,4-benzenedicarboxylic acid, 1,4-H2CHDA = 1,4-cyclohexanedicarboxylic acid, H2HIPA = 5-hydroxyisophthalic acid, H2MIP = 5-methylisophthalic acid and H4PMA = pyromellitic acid] have been synthesized under hydrothermal conditions. 1 shows a 4-c sql coplanar structure. 2 exhibits a 2-fold vertical interpenetrating structure based on wave-like 4-c sql layers. 3 shows a (3,5)-c pnh network containing a unique μ3-L. 4 features a 4-c sql wave-like network. 5 and 6 exhibit 3D structures with 6-c pcu and 4-c mog topologies. The number of carboxyl groups and functional group positions of the carboxylates have an important influence on the structures of the title complexes. The fluorescent responses of 1-6 towards Fe3+, anions, aspartic acid and bovine serum albumin were investigated. Among them, 4 shows sensitivity and selectivity (KSV = 1.16 × 104 L mol-1 for Fe3+, 1.03 × 104 L mol-1 for CrO42-, 1.08 × 104 L mol-1 for Cr2O72-, 1.17 × 104 L mol-1 for MnO4- and 1.05 × 104 L mol-1 for aspartic acid).

The impact of electrolytes on the adsorption of emerging pollutants: pharmaceuticals onto layered materials: a raw clay mineral and its nonionic and cationic organoclay derivatives was studied. The selected pharmaceuticals: amoxicillin, norfloxacin, sulfamethoxazole, metoprolol, carbamazepine, and trimethoprim show different electric charges: zwitterionic, anionic, cationic and neutral and hydrophobic character (different LogP). Without any salts, the set of complementary data obtained by UV and infrared spectroscopies, X-ray diffraction points out the importance of the electric charge which represents a key parameter in both the spontaneity and feasibility of the adsorption. In contrast, the hydrophobicity of the analytes plays a minor role but determines the magnitude of the adsorbed amount of pharmaceuticals onto organoclays. With a dual hydrophilic and hydrophobic behavior, nonionic organoclay appears to be the most polyvalent material for the removal of the pharmaceuticals. In the presence of electrolytes (NaCl at a concentration of 1 × 10 -2  mol L -1 ), both nonionic and cationic organoclays show a decrease of their efficiencies, whereas the adsorption is particularly enhanced for Na-Mt except for the cationic species (trimethoprim and metoprolol). Thus, in realistic experimental conditions close to those of natural effluents, raw clay mineral appears as the most appropriate sorbent for the studied pharmaceuticals while it raises the question of the usefulness of organoclays in water remediation strategy., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Flowback and produced water generated by the hydraulic fracturing of unconventional oil and gas plays contain a suite of cations (e.g., metals) typically in a high salt (e.g., NaCl) matrix. Here, we analyzed the chemical (cation) composition of production fluids associated with natural gas and oil development (e.g., flowback, produced water, impoundment fluids), along with mine drainage, and surface and ground water samples using ICP-OES and ICP-MS. ICP-MS and ICP-OES analytical performance and interference effects were evaluated. Both platforms exhibited excellent analytical spike recoveries, detection limits for blank and spiked solutions, and accuracy for standard certified reference materials. Mass ratio analyses using Ca/Sr, Ca/Mg, Ba/Sr, Mg/Sr, and B and Li, were assessed for their efficacy in differentiation among brines from conventional oil wells, produced water from unconventional oil and gas wells and impoundments, mine drainage treatment pond water, groundwater, and surface water. Examination of Mg/Sr ratios when compared with Li concentrations provide clear separation among the different types of samples, while Ca/Mg versus Ca/Sr correlations were useful for distinguishing between conventional and unconventional oil and gas fluids.

In many parts of the world, wastewater irrigation has become a common practice because of freshwater scarcity and to increase resource reuse efficiency. Wastewater irrigation has positive impacts on livelihoods and at the same time, it has adverse impacts related to environmental pollution. Hydrochemical processes and groundwater behaviour need to be analyzed for a thorough understanding of the geochemical evolution in the wastewater irrigated systems. The current study focuses on a micro-watershed in the peri-urban Hyderabad of India, where farmers practice intensive wastewater irrigation. To evaluate the major factors that control groundwater geochemical processes, we analyzed the chemical composition of the wastewater used for irrigation and groundwater samples on a monthly basis for one hydrological year. The groundwater samples were collected in three settings of the watershed: wastewater irrigated area, groundwater irrigated area and upstream peri-urban area. The collected groundwater and wastewater samples were analyzed for major anions, cations and nutrients. We systematically investigated the anthropogenic influences and hydrogeochemical processes such as cation exchange, precipitation and dissolution of minerals using saturated indices, and freshwater-wastewater mixtures at the aquifer interface. Saturation indices of halite, gypsum and fluorite are exhibiting mineral dissolution and calcite and dolomite display mineral precipitation. Overall, the results suggest that the groundwater geochemistry of the watershed is largely controlled by long-term wastewater irrigation, local rainfall patterns and water-rock interactions. The study results can provide the basis for local decision-makers to develop sustainable groundwater management strategies and to control the aquifer pollution influenced by wastewater irrigation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Identifying the types of contamination and their sources in surface and groundwater is fundamental for effective protection of private and public source waters. Here we employed mass ratio analyses of a variety of anion and cation pairs to characterize flowback, produced water, and mine drainage. These endmembers were used to evaluate the source contributions of natural surface and ground water samples. A total of 1,177 ground water and surface water samples were analyzed including high-quality source waters and waters suspected of being impacted by drilling and mining activity. We found the following chemical ratios resolved different sources of contamination: Mg/Na vs SO 4 /Cl; SO 4 /Cl vs Mg/Li; Br/SO 4 vs Ba/Cl; and Br vs Mg/Li. While no single parameter or mass ratio pairing by itself was definitive it was possible to converge on a likely source of contamination using multiple lines of analytical evidence. Further, this process clarified sources in impacted samples where one or more parameters commonly considered diagnostic of specific sources (e.g., Br, Ba), were below detection limits (e.g., too dilute) or not tested for. Ultimately, movement of sample values within the mass ratio space allows tracking of changes in water quality and contamination source dynamics as the water chemistry evolves.

Synthesis and chelation induced fluorescence emission from two imidazo[1,2-a]pyridine derivatives are described. The nonfluorescent molecule 1 containing N and O donor atoms, achieves coplanarity upon interactions with trivalent cations Al 3+ , Fe 3+ and Cr 3+ , that favors fluorescence emission. Molecule 2 containing two N donor atoms attains coplanarity upon interaction with the only Zn 2+ and becomes fluorescent. Both molecules 1 and 2 form a 1:1 complex with interacting metal ions. Other trivalent metal ions (including Bi 3+ and In 3+ ) and common divalent metal ions (including Hg 2+ and Cd 2+ ) fail to form any complex with 1 or 2, and they do not interfere in the detection of Zn 2+ , Al 3+ , Fe 3+ or Cr 3+ ions. Noninterference of other metal ions renders 1 and 2 suitable for the detection of fungal cells contaminated with Zn 2+ , Al 3+ , Fe 3+ or Cr 3+ ions., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A novel quinoline-based Schiff-base probe QL had been synthesized, which could sequentially monitor Al 3+ and F - in MeOH-H 2 O solution (v/v = 8/1, 0.01 M, HEPES buffer, pH = 7.3). The probe QL expressed a high selective and sensitive "OFF-ON-OFF" fluorescent response for Al 3+ and F - (excitation at 460 nm and emission at 530 nm) accompanying visible color changed, which was ascribed to intramolecular charge transfer (ICT) process and chelation-enhanced fluorescence (CHEF) mechanism. The binding stoichiometry of QL with Al 3+ was 2:1 counting on Job's plot and HRMS, while F - could pull Al 3+ to depart from the complexation 2QL-Al 3+ and released free QL. The limit of detections of probe QL for Al 3+ and F - ions were calculated to be 0.10 μM and 0.50 μM. The 1 H NMR experiments and density functional theory (DFT) calculations were carried out to further prove the binding mode between QL and Al 3+ . Furthermore, fluorescence imaging studies demonstrated that the probe QL was low cytotoxicity and could be applied to detect Al 3+ and F - in living PC12cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

An effective morpholine-type naphthalimide chemsensor, N-p-chlorophenyl-4-(2-aminoethyl)morpholine-1,8-naphthalimide (CMN) has been developed as a lysosome-targeted fluorometric sensor for trivalent metal ions (Fe 3+ , Al 3+ and Cr 3+ ). Upon the addition of Fe 3+ , Al 3+ or Cr 3+ ions, the probe CMN showed an evident naked-eye color changes which pale yellow solution of CMN turned deepened and it displayed turn-on fluorescence response in methanol. CMN showed a significant selective and sensitive toward Fe 3+ , Al 3+ or Cr 3+ ions, while there was no obvious behavior to other monovalent or divalent metal ions from the UV-vis and fluorescence spectrum. Based on the Job's plot analyses the 1:1 coordination mode of CMN with Fe 3+ , Al 3+ or Cr 3+ was proposed. The limit of detection (LOD) observed were 0.65, 0.69 and 0.68 μM for Fe 3+ , Al 3+ and Cr 3+ ions, respectively. The N-atom of morpholine directly involved in complex formation, CMN emitted fluorescence through inhibition of photoinduced electron transfer (PET). This probe exhibited excellent imaging ability for Fe 3+ , Al 3+ and Cr 3+ ions in living cells with low cytotoxicity. Significantly, the cellular confocal microscopic research indicated that the lysosome-targeted group of morpholine moiety was introduced which realized the capability of imaging lysosomal trivalent metal ions in living cells for the first time., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The aim of this paper is to design near-infrared (NIR) Al 3+ fluorescent probes based on a Schiff base to extend their applications in biological systems. By combining benzo[ h ]quinoline unit and salicylaldehyde acylhydrazone, we designed two new Schiff base derivatives. According to theoretical simulations on previous experimental Al 3+ probes, we obtained the appropriate theoretical approaches to describe the properties of these fluorescent probes. By employing such approaches on our newly designed molecules, it is found that the new molecules have high selectivity toward Al 3+ and that their corresponding Al 3+ complexes can emit NIR fluorescence. As a result, they are expected to be potential NIR Al 3+ fluorescent probes.

We report on facile synthesis and characterization of phosphate-functionalized polymer dots (PDs) by doping tributyl phosphate (TBP) in a semiconducting polymer poly[9,9-dioctylfluorenyl-2,7-diyl)-co-1,4-benzo-{2,10-3}-thiadiazole)] (PFBT). Then, the prepared TBP@PFBT PDs were used to develop a very high sensitive probe for detection Fe 3+ , Cu 2+ ions and Cytochrome c based on aggregation induced fluorescence off mechanism. The PDs exhibited a linear dynamic range for Fe 3+ from 0.1 to 2 nM with a detection limit of 30 pM and for Cu 2+ from 2.0 to 50.0 nM with a detection limit of 0.35 nM. Meanwhile, this probe showed a linear dynamic range for Cyt c from 175 to 1750 pM with a detection limit of 32.7 pM. The TBP@PFBT PDs is a simple, one-step, fast, non-invasive, label-free, and inexpensive probe that is capable of online apoptosis monitoring response to drugs with an ever-present opportunity to contribute in a variety of in-vitro and in-vivo biological applications. We also obtained sharp, specific 2D and 3D imaging results for early stage apoptosis in breast cancer cells. Moreover, this technique possesses the advantage of rapid determination of Fe 3+ ion in biological or environmental samples. Importantly, this label-free assay provides short determination time of only a few min, easy operation and very low LOD allowing 100-4000 times increased in sensitivity over previously reported probes, together with high selectivity without need to using biorecognition elements like enzymes, antibodys and/or aptamers. Such excellent features make the TBP@PFBT PDs an excellent probe for successful apoptosis imaging in live cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In recent years, transition metal complexes with their prominent photophysical properties have emerged as versatile chemosensors to probe different target analytes, including metal ions. By incorporating specific metal ion receptors, various iridium(III) complex-based cation sensors have been developed using different mechanisms. In this review, we survey examples of iridium(III) complex-based metal ion chemosensors that have been reported in the literature. Their design, mechanism and outlook will also be discussed., (Copyright © 2019 Elsevier Inc. All rights reserved.)

This paper describes a new fluorescent chemosensor (DSH) based on dipeptide conjugated with dansyl group, which was synthesized by solid phase peptide synthesis (SPPS) technology. DSH exhibited a highly selective and sensitive toward Zn 2+ ions by "turn-on" response based on generation of monomer-excimer mechanism in aqueous solutions, and the detection limit was calculated at 11.2 nM. In addition, the reversible of DSH-Zn with Na 2 EDTA establishes the reuse of DSH, and the circulation effect was very good. Moreover, DSH had good water solubility, and was successfully applied to bioimage intracellular Zn 2+ ions and Na 2 EDTA in two different living cells with exciting cellular permeability and low cytotoxicity, which indicated that DSH had great potential in the application of biological imaging., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Palladium (Pd) has drawn worldwide attentions because its connections to industry, chemistry, biological material and public health. Quantitative and selective detection tools for Pd and its ion forms are in urgent necessity. Here an umbelliferone derivative Umb-Pd2 was provided as a small, steady, safe and selective sensor for detecting Pd(II). It indicated advantages including sensitive (LOD 1.1 nM), wide pH tolerance (5.0-10.0), applicable linear range (0-1.8 equivalent) and low toxicity. The most attractive point was its explicit selectivity towards Pd(II) from Pd(0) in both independent and coexistence systems. This distinguishing ability was further utilized in imaging in living cells, raising this work as a rare and important example among all the published papers on palladium sensing. Thus, Umb-Pd2 supplied a potential approach for further improvement and applications in both daily chemistry and public health., (Copyright © 2019. Published by Elsevier B.V.)

A photoinduced electron transfer (PET) and chelation-enhanced fluorescence (CHEF) regulated rhodamine-azobenzene chemosensor (L) was synthesized for chemoselective detection of Al 3+ , Cr 3+ , and Cu 2+ by UV-Visible absorption study whereas Al 3+ and Cr 3+ by fluorimetric study in EtOH-H 2 O solvent. L showed a clear fluorescence emission enhancement of 21 and 16 fold upon addition of Al 3+ and Cr 3+ due to the 1:1 host-guest complexation, respectively. This is first report on rhodamine-azobenzene based Cr 3+ chemosensor. The complex formation, restricted imine isomerization, inhibition of PET (photo-induced electron transfer) process with the concomitant opening of the spirolactam ring induced a turn-on fluorescence response. The higher binding constants 6.7 × 10 3  M -1 and 3.8 × 10 3  M -1 for Al 3+ and Cr 3+ , respectively and lower detection limits 1 × 10 -6  M and 2 × 10 -6  M for Al 3+ and Cr 3+ , respectively in a buffered solution with high reversible nature describes the potential of L as an effective tool for detecting Al 3+ and Cr 3+ in a biological system with higher intracellular resolution. Finally, L was used to map the intracellular concentration of Al 3+ and Cr 3+ in human lymphocyte cells (HLCs) at physiological pH very effectively. Altogether, our findings will pave the way for designing new chemosensors for multiple analytes and those chemosensors will be effective for cell imaging study., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A study was conducted to evaluate the effects of feeding an acidogenic diet with a low dietary cation-anion difference (DCAD) on acid-base balance, blood, milk, and urine Ca concentrations of sows during lactation. A total of 30 multiparous sows (parity: 4.5 ± 2.9, Smithfield Premium Genetic, Rose Hill, NC) were allotted to 1 of 2 dietary treatments: CON (control diets were corn-soybean meal based with a calculated DCAD of 170 and 226 mEq/kg during late gestation and lactation, respectively) or ACI (acidogenic diets had a DCAD 100 mEq/kg lower than the control diets). The lower DCAD was achieved by the addition of an acidogenic mineral. The DCAD was calculated as mEq (Na + K - Cl)/kg diet. Sows had a daily access to 2-kg feed from day 94 of gestation to parturition and ad libitum access to feed during lactation. Blood and urine pH and Ca, serum macrominerals, serum biochemistry, Ca-regulating hormones, and milk composition were measured. Sows in ACI had a lower (P < 0.05) blood pH than sows in CON at day 1 of lactation. Sows in ACI had a lower (P < 0.05) urine pH at day 108 of gestation, days 1, 9, and 18 of lactation compared with sows in CON. Sows in ACI had greater (P < 0.05) concentrations of serum total Ca at days 1 and 18 of lactation than sows in CON. There was a greater (P < 0.05) concentration of colostrum Ca in ACI than in CON. There was no difference in urine Ca concentration between treatments during lactation. Concentrations of parathyroid hormone and 1,25-dihydroxycholecalciferol were not different between treatments at either day 1 or 18 of lactation. Sows in ACI tended to have a smaller (P = 0.086) concentration of total alkaline phosphatase in serum at day 18 of lactation compared with sows in CON. At day 1 of lactation, the concentration of serum Cl in ACI was greater (P < 0.05) than that in CON. Feed intake, BW loss, and litter performance were not different between treatments. Collectively, feeding an acidogenic diet with a low DCAD to sows can induce a mild metabolic acidosis at farrowing, reduce the urine pH consistently, and increase serum total Ca and colostrum Ca concentrations during lactation but without altering the parathyroid hormone and 1,25-dihydroxycholecalciferol levels during lactation., (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Capillary electrophoresis (CE) is excellent at separating all the ions in a sample but is rarely used as a result of its detection issue and easy loss of very fast ions by common one-end injection methods. Herein we propose a newly developed method aimed at simultaneous determination of positive and negative ions with a home-made CE device, featuring bi-end injection and contactless conductivity detection at the middle. By simply using 2.5 M acetic acid as a running buffer, the method can separate 37 ions (3 inorganic anions, 8 inorganic cations, 10 biogenic amines, and 16 amino acids) per run, with linearity between 10 and 2000 μM (R 2  > 0.99), limit of detection of 1.0-16.6 μM, and limit of quantification of 2.3-31.7 μM. The recovery measured by spiking standards into samples at high, middle, and low levels was between 73% and 110%. The intra- and interday repeatability of the 37 analytes ranged from 0.69% to 8.97% and from 0.68% to 11.04%, respectively. The proposed method was evaluated by analysis of 21 beers and, in addition to acquiring the concentration information, the brands of the tested beers were distinguished. This method is of high throughput, fast, and cost-effective. It could be a promising tool for ionomic analysis. Graphical abstract ᅟ.

Polysiloxanes have excellent stability and biological relevance and are suitable for biological research. However, there were few polysiloxane-based fluorescent probes for bioimaging. This report successfully designed a new polysiloxane-based polymer fluorescent probe (RB-1) for the first time as a "turn-on" fluorescent probe response to Al 3+ ion with highly sensitive and selectivity. Importantly, this probe could also apply both in cell and zebrafish imaging, indicating the huge application development prospects of polysiloxane-based fluorescent probes in future., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Exogenous calcium can enhance the resistance of certain plants to abiotic stress. Research have demonstrated that exogenous calcium could enhances the resistance of honeysuckle under salt stress by promoting the transmission of photosynthetic electrons.The aim of this study was to investigate the effects of exogenous calcium on the contents of Na~+,K~+,Ca~(2+),Mg~(2+)and the expression of photosynthetic related genes Cab and rbc L. In this study,we used ICP-OES to analysis ion contents and used qRT-PCR to analysis the expression patterns of Cab and rbc L. The results showed that CaCl&#95;2 significantly enhanced the K~+-Na~+,Ca~(2+)-Na~+,Mg~(2+)-Na+ratio of honeysuckle treated with 50 and 100 mmol·L~(-1) NaCl. Meanwhile,Cab and rbc L were significantly up-regulated under short-term salt stress,and CaCl&#95;2 promoted this trend. From the two gene expression patterns,rbc L rapidly up-regulated on the first day of stress and then decreased,and was more sensitive to environmental changes. In summary,exogenous calcium could alleviate salt stress and increase plant development by increasing intracellular K~+-Na~+,Ca~(2+)-Na~+,Mg~(2+)-Na+ratio,and the transient overexpression of Cab and rbc L.

Water quality for drinking and irrigation usage was examined in Kardeh dam basin in NE Iran. Thirty-two surface and groundwater samples were collected and analyzed for major ions of Ca 2+ , Mg 2+ , Na + , K + , HCO 3 - , CO 3 2- , SO 4 2- and Cl - by using standard analytical methods of titration and atomic absorption spectrophotometry at geochemistry laboratory of Ferdowsi University of Mashhad. Dominant cation in most of the water samples are Ca 2+ and Mg 2+ , and dominant anion is HCO 3 - . Water quality index (WQI) was calculated based on physicochemical parameters such as pH, EC and major ions. The WQI values were less than 100 (maximum permissible value) for all samples and suitable for drinking usage; nevertheless, water quality decreased from northwest toward the southeast of studied area. Also, based on modified NSFWQI, the water resources were classified into average and good categories, which are suitable for irrigation uses. More than 40% of the samples are not suitable for irrigation uses based on magnesium hazard values. Carbonate rocks have the main effect on hydrogeochemical facies and the water quality in studied area. According to drinking and irrigation indices, water quality is reducing from upstream toward downstream to the southeast of the basin.

In 2008, the Mulberry River, a National Wild and Scenic River, was listed as impaired due to low pH (below pH 6.0). Over the last 50 years, the volume of conifers in the Ozark region has increased 115% since 1978 which may result in the acidification of nearby aquatic ecosystems. The objective of this study was to determine if differences exist in soil and litter chemical properties between deciduous and coniferous tree stands. Aboveground litter (n = 200) and soil (n = 400) at 0- to 5- and 5- to 15-cm depths were collected at paired deciduous and coniferous stands at 10 locations within the Mulberry River watershed and analyzed for a suite of chemical parameters. There were no differences (P > 0.05) in several measures of soil acidity between deciduous and coniferous stands. Litter collected from the coniferous stands was more acidic than deciduous litter (4.4 vs 4.7; P < 0.05). Cation exchange capacity, exchangeable Ca and Mg, and water-soluble P and Mg contents differed (P < 0.05) by stand and depth. Cation exchange capacity and exchangeable Ca and Mg were greatest in the 0- to 5-cm depth interval of the coniferous stands. Water-soluble P and Mg contents were greatest within the 0- to 5-cm depth interval which did not differ (P > 0.05) between stand but were greater than the 5- to 15-cm depth interval. Although limited to the top 15-cm of soil, the similarity in soil acidity between stands suggests that conifer growth may not be a substantial source of acidity to the Mulberry River.

In this study, we investigated the lipopolysaccharide (LPS)-neutralizing and angiogenic activities of cationic peptides derived from the traditional Japanese fermented product Natto, which is made by fermenting cooked soybeans using Bacillus subtilis. Initially, we prepared 20 fractions of Natto extracts with various isoelectric points (pI's) using ampholyte-free isoelectric focusing (autofocusing). Cationic peptides were then purified from fractions 19 and 20, whose pH values were greater than 12, using reversed-phase high-performance liquid chromatography, and were identified using matrix-assisted laser/desorption ionization-time-of-flight mass spectroscopy. Among the 13 identified cationic peptides, seven (KFNKYGR, FPFPRPPHQK, GQSSRPQDRHQK, QRFDQRSPQ, ERQFPFPRPPHQK, GEIPRPRPRPQHPE, and EQPRPIPFPRPQPR) had pI's greater than 9.5, positive net charges, and differing molecular weights. These peptides were then chemically synthesized and applied to chromogenic LPS-neutralizing assays using Limulus amebocyte lysates, and 50% effective (neutralizing) concentrations of 2.6-5.5 μM were demonstrated. In addition, tube formation assays in human umbilical vein endothelial cells revealed angiogenic activities for all but one (GEIPRPRPRPQHPE) of these seven cationic peptides, with increases in relative tube lengths of 23-31% in the presence of peptides at 10 μM. Subsequent experiments showed negligible hemolytic activity of these peptides at concentrations of up to 500 μM in mammalian red blood cells. Collectively, these data demonstrate that six cationic peptides from Natto extracts, with the exception of GEIPRPRPRPQHPE, have LPS-neutralizing and angiogenic activities but do not induce hemolysis., (Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

This study compares the biosensing performance of a microbial fuel cell (MFC) and a microbial electrolysis cell (MEC). Initial tests provided a qualitative comparison of MFC and MEC currents after the anode compartment liquid (anolyte) was spiked with acetate, or sulphates of NH 4 + , Na + , Mg 2+ , Fe 2+ , or a fertilizer solution. Current measurements showed that the MFC sensor had a faster response time, higher sensitivity, and faster recovery time after the spike. Following the spike tests, the MFC and MEC were operated in a continuous flow mode at several influent concentrations of acetate, and sulphates of NH 4 + , Na + , and Fe 2+ . The continuous flow tests confirmed the better performance of the MFC sensor, which was selected for further experiments. Two MFC sensors were used for real-time (on-line) COD measurements of brewery wastewater. Regression analysis showed a strong correlation between the MFC power output and COD concentrations in the anode compartment with a coefficient of determination (R 2 ) of 0.97. Overall, results of this study suggest that an MFC-based sensor can be successfully used as a simple and cost-efficient real-time monitoring tool., (Copyright © 2018. Published by Elsevier B.V.)

An analytical method for concurrent analysis of inorganic anions and cations has been developed using a capillary electrophoresis (CE)-capacitively coupled contactless conductivity detector (C 4 D) system. Although hydrodynamic and electrokinetic injection techniques have been widely used in CE, we employed a capillary filling method (CFM) for the analysis of inorganic ions. The procedure is relatively simple and has the advantage that CMF does not require pressure control and vial exchange. Three anions (chloride, sulfate, nitrate) and five cations (ammonium, potassium, sodium, magnesium, calcium) were successfully separated and detected at ppm levels within 80 s using a 9 mM histidine/15 mM malic acid (pH 3.6) containing 50 mM N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate as background electrolyte. Applying this analytical condition, the electroosmotic flow is negligible and anions and cations were migrated concurrently to different polarities according to their electrophoretic mobility. Obtained raw data showed stepwise increases in detected conductivity due to the migration of sample components, which expresses as peak profiles by differentiation of electropherograms. The RSD values of the peak area and migration times for the anions and cations were satisfactory and were less than 5.15 and 2.04%, respectively. The developed method was applied for the analysis of inorganic anions and cations in commercial mineral waters, tap water, urine, and exhaled breath condensate. These results indicate that the CE-C 4 D system with CFM is suitable for the rapid analysis of inorganic anions and cations in various samples.

In view of the significant risk of heavy metal ions on human health, effective determination method is quite urgent. Herein, a single-walled carbon nanohorns modified screen-printed electrode was proposed as a disposable electrochemical sensor. The electrochemical study reveals that the developed electrode possesses excellent electrochemical activity. By combination of bismuth film, the electrochemical sensor exhibits distinct and detached stripping peaks towards cadmium and lead. Under the optimized conditions, the linear range of the single-walled carbon nanohorns film modified electrode for both heavy metal ions varied from 1.0 to 60.0 μg L -1 . The detection limit of cadmium (II) and lead (II) ions was 0.2 μg L -1 and 0.4 μg L -1 . Furthermore, the determination of cadmium (II) and lead (II) ions in honey and milk samples illustrates the prepared electrochemical sensor possesses excellent practicability for determining cadmium (II) and lead (II) ions in a low levels (μg L -1 )., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Amines are frequently used as additives in supercritical fluid chromatography (SFC). They allow eluting basic analytes with reasonable retention times and less distorted peak shapes. Since amines are chemically active compounds, their introduction into SFC mobile phase always raises a question on whether they can react with analytes or mobile phase constituents and, if so, can it affect chromatography separation. Primary and secondary amines are known to react with carbon dioxide, also all amines, being bases, can interact with CO 2 -alcohol mixtures which are known to be slightly acidic. In this work, we report a case of separate elution of an ammonium salt, salbutamol sulfate, anion and cation in SFC. Retention time of a peak which molecular mass registered by mass-spectrometry in ES(-) mode corresponds to HSO 4 - differs substantially from the retention time of a peak corresponding to salbutamol [M+H] registered in ES(+) regime. Moreover, sulfate anion retention time depends both on amine additive type and concentration whereas salbutamol retention time doesn't. Similar effect is observed on other columns as well as with other ammonium salts. We suppose that such behavior is caused by the exchange chemical reaction happening between ammonium salt analyte and amine additive. An additive converts a salt into a free base form and turns into a salt form itself. If this hypothesis is true, it might be important to take the possibility of such interactions into account during preparative SFC work since the compound injected might not be equivalent to a compound eluted., (Copyright © 2018 Elsevier B.V. All rights reserved.)