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Analysis of U in the samples containing a significant proportion of 232U and high concentration of Th is of great concern. Transmutation of Th in the nuclear power reactor produces a notable quantity of 232U (half life 68.9 years) along with fissile isotope 233U. The decay series of 232U is initiated with 228Th (half life 1.9 year) and it is followed by several short lived α emitting progenies, 224...
Topoisomerase I inhibitor topotecan (TPT) is the only single-agent therapy certified for the remedy of repetitive small cell lung cancer (SCLC). In this study, TPT was labeled with 131I via iodogen method and its quality control was determined using thin layer radiochromatography and paper electrophoresis methods. Intracellular uptake study was carried out with human lung adenocarcinoma cell line...
An analytical scheme for physical fractionation of Al, Ba, Ca, Co, Fe, K, Mg, Mn, Na, Ni, Sr and Zn in ground roasted and soluble coffees brews was proposed. It was based on ultrafiltration through five ultrafiltration membranes having molecular weight cut-offs of 5, 10, 30, 50 and 100kDa. The highest “>100kDa” and the lowest “<5kDa” molecular weight fractions were established to differentiate...
The search of a practical method to analyze cis-diol-containing compounds outside laboratory settings remains a substantial scientific challenge. Herein, a smartphone-based colorimetric reader was coupled with a remote server for rapid on-site analysis of catechols. A smallest-scale 2×2 colorimetric sensor array composed of pH indicators and phenylboronic acid was configured. The array was able to...
Upon near-infrared excitation Tm3++Yb3+ doped fluorohafnate glasses present upconversion properties and emit visible light. This property permits to use these glasses (UCG) as excitation sources for fluorescent optical biosensors. Taking this into account, in this work a fluorescent biosensor for glucose determination is designed and evaluated. The biosensor combines the UCG and the fluorescence of...
Aptamer-ligand binding has been utilized for biological applications due to its specific binding and synthetic nature. However, the applications will be limited if the binding or the ligand is unstable. Malachite green aptamer (MGA) and its labile ligand malachite green (MG) were found to have increasing apparent dissociation constants (Kd) as determined through the first order rate loss of emission...
A sensitive analytical procedure for the determination of four haloanisoles (2,4,6 trichloroanisole, 2,4,6-tribromoanisole, 2,3,4,6-tetrachloroanisole and pentachloroanisole) related with cork taint defects in wines, in different types of alcoholic beverages has been developed. The analytes were extracted from the matrix samples by cloud point extraction (CPE) using Triton X-114 heated to 75°C, and...
A Square Wave Voltammetry electrochemical method is proposed to measure phosphate in seawater as pulse techniques offer a higher sensitivity as compared to classical cyclic voltammetry. Chronoamperometry cannot be either adapted for an in situ sensor since this method requires to have controlled convection which will be impossible in a miniaturised sensor. Tests and validation of Square Wave Voltammetry...
A new type of deep eutectic solvents (DESs) have been prepared and used as extraction solvents for ultrasound assisted-deep eutectic solvent based emulsification liquid phase microextraction method (UA-DES-ELPME) for the determination and speciation of total chromium, chromium(III) and chromium(VI). The chromium concentration in DES rich phase (extraction phase) was determined by using microsample...
This work describes the state of the art of electrochemical devices for the detection of an important class of neurotransmitters: the catecholamines. This class of biogenic amines includes dopamine, noradrenaline (also called norepinephrine) and adrenaline (also called epinephrine).Researchers have focused on the role of catecholamine molecules within the human body because they are involved in many...
The feasibility of accurate-mass multi-residue screening methods using liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS) using time-of-flight mass spectrometry has been evaluated, including over 625 multiclass food contaminants as case study. Aspects such as the selectivity and confirmation capability provided by HRMS with different acquisition modes (full-scan or full-scan combined...
Measurement of radionuclides in marine samples, specifically radioactive pairs disequilibrium, has gained interest lately due to their ability to trace cutting edge biogeochemical processes. In this context, we developed a fast, direct method for determining 210Pb and 210Po water through the use of ultra low-level liquid scintillation counting and alpha-particle spectrometry respectively and through...
A simple and highly sensitive electrochemical sensor based on an electrochemically reduced graphene oxide-modified screen-printed carbon electrode (ERGO-SPCE) for the simultaneous determination of sunset yellow (SY) and tartrazine (TZ) was proposed. An ERGO film was coated onto the electrode surface using a cyclic voltammetric method and then characterized by scanning electron microscopy (SEM). In...
Comprehensive hyphenated two-dimensional liquid chromatography mass spectrometry (LC×LC-MS) is a very powerful analytical tool achieving high throughput resolution of highly complex natural samples. However, even using this approach there is still the possibility of not resolving some of the analytes of interest. For instance, triacylglycerols (TAGs) structural isomers in oil samples are extremely...
Poly (glycidylmethacrylate-divinylbenzene) (Poly (GMA-DVB)) microspheres were prepared by the two-staged swelling and polymerization method, and modified with octadecylamine (ODA) to obtain ODA-poly (GMA-DVB) stationary phase for HPLC. The new material was characterized by scanning electron microscope, nitrogen adsorption-desorption measurement, Fourier transform infrared spectrum, elemental analysis...
An analytical scheme for the physical fractionation of Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Sr and Zn in black and green teas infusions was proposed. It was based on the ultrafiltration/centrifugation through five membranes having molecular weight cut-offs of 100, 50, 30, 10 and 5kDa. The concentrations of the studied metals in the highest and the lowest molecular weight fractions were found...
Grape seeds were collected in ten different dates and classified in seven groups according to their individual hyperspectral imaging characteristics.Proanthocyanidin composition was studied using HPLC-MS for oligomers and acid catalyzed cleavage for polymers characterization. The combination of both analysis provided a complete description of the flavanols. Chemometric analysis was performed to summarize...
A method to determine the quantity and isotopic ratios of uranium in individual micro-particles simultaneously by isotope dilution thermal ionization mass spectrometry (ID-TIMS) has been developed. This method consists of sequential sample and spike loading, ID-TIMS for isotopic measurement, and application of a series of mathematical procedures to remove the contribution of uranium in the spike....
Small molecules that may facilitate and stabilize the formation of G-quadruplexes can be used for cancer treatments, because the G-quadruplex structure can inhibit the activity of telomerase, an enzyme over-expressed in many cancer cells. Therefore, there is considerable interest in developing a simple and high-performance method for screening small molecules binding to G-quadruplex. Here, we have...
A new simple methodology is proposed for chlorsufuron (CS) traces quantification based upon enhancement of rhodamine B (RhB) fluorescent signal. Experimental variables that influence fluorimetric sensitivity have been studied and optimized. The zeroth order regression calibration was linear from 0.866 to 35.800µgL−1 CS, with a correlation coefficient of 0.99. At optimal experimental conditions, a...
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