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Present paper describes the results of a novel method which combines the Head space (HS) preconcentration of the analyte on the electrode prior to the voltammetric analysis. Thereafter, the method was called HS-Voltammetry. The performance of the method was tested upon using an electroactive and volatile molecule, phenol molecule, which gives an oxidation peak at conventional electrodes. In this study,...
In this paper a novel calibration procedure for the parameter determination of ion-selective electrodes used in an array is described. Commonly used procedures require a large number of standards to determine the parameters based on the Nicolsky–Eisenman model. The elaborated procedure reduces the number of standards to a minimum by using a standard containing a mixture of ions instead of a couple...
In the present study, toluidine blue–graphene (Tb–Gra) nanocomposites were prepared to design a Lable-free electrochemical aptasensor for highly sensitive detection of thrombin based on layer-by-layer (LBL) technology. The nanocomposites with excellent redox electrochemical activities were first immobilized on the gold nanoparticles (nano-Au) modified glassy carbon electrodes (GCE). Then, the LBL...
There is limited and inconclusive information regarding detectable limits and linear dynamic ranges of various quantitative protein assays. We thus performed systematic comparisons of seven commonly used methods, including direct spectrophotometric quantitation at λ205 and λ280nm (A205 and A280, respectively), bicinchoninic acid (BCA), Biuret, Bradford, Lowry and Ninhydrin methods. Purified BSA, porcine...
We have explored a novel dual-function stationary phase which combines both strong cation exchange (SCX) and hydrophobic interaction chromatography (HIC) characteristics. The novel dual-function stationary phase is based on porous and spherical silica gel functionalized with ligand containing sulfonic and benzyl groups capable of electrostatic and hydrophobic interaction functionalities, which displays...
The rod-shaped SBA–15–C 18 mesoporous nanoparticles were incorporated into hybrid organic–inorganic monolithic column with aminopropyl moiety to develop novel stationary phases with mixing mechanism of reverse phase and ion exchange. Experimental conditions including dispersion pattern, nanoparticles percentage were optimized for simple and stable column preparation. The monolithic columns...
A rapid and sensitive method using two preconcentration techniques, dispersive liquid–liquid microextraction (DLLME) followed by reversed electrode polarity stacking mode (REPSM) was developed for the analysis of five organophosphorus pesticides (OPPs) by micellar electrokinetic chromatography (MEKC). Parameters that affect the efficiency of the extraction in DLLME and preconcentration by REPSM, such...
A flow sensor for trace analysis of zinc, using graphite felt as working electrode is reported here. A flow cell, well-adapted to 3-D porous electrodes and capable to do both the preconcentration step at a cathodic potential and the stripping of the zinc was successfully developed. It was demonstrated that this cell allows to obtain better electrochemical signals for Zn 2+ compared to a standard...
The effects of grinding size and shaking process on the results of Cd (cadmium), Pb (lead) and Zn (zinc) distribution measurements three agricultural and three kitchen garden soils highly contaminated by past atmospheric fallout of two lead and zinc smelters in northern France were studied. The physico-chemical parameters and pseudo-total concentration of metals within these soils were determined...
In this work, a new method based on the combination of dispersive liquid–liquid microextraction (DLLME) with microvolume spectrophotometry has been developed as a greener and miniaturized alternative to the 5530 APHA standard method for determining phenols in water and wastewater. The method relies on the oxidative coupling of phenols with 4-aminoantipyrine (4-AAP). In order to preconcentrate the...
A poly(p-phenylenediamine-co-aniline) composite coating was prepared on a stainless steel wire through electrochemical method. The coating was characterized by scanning electron microscopy, Fourier transform infrared spectrophotometry and thermogravimetry. It showed thin slice shape and netlike microstructure, and thus it had large surface area and large extraction capacity. When the resulting fiber...
The CdS/TiO 2 –fluorescein isothiocyanate (FITC) luminescent nanoparticles (CdS/TiO 2 –FITC) with the particle size of 20nm have been synthesized by sol–gel method. CdS/TiO 2 –FITC could emit the fluorescence of both FITC and CdS/TiO 2 . The fluorescence resonance energy transfer (FRET) occurred between the donor CdS/TiO 2 and the acceptor FITC in the CdS/TiO...
A fast, facile, and economical assay for basic nitrogenous drugs has been developed based on the mini-scale extraction of the drug–dye ion pair complex combined with the use of safe-for-analyst and eco-friendlier organic extractant and drop-based micro-spectrophotometry. Instead of using large volume devices, the extraction was simply carried out in typical 1.5mL microcentrifuge tubes along with the...
Aim of this work is to assess the potentialities of the X-ray powder diffraction technique as fingerprinting technique, i.e. as a preliminary tool to assess soil samples variability, in terms of geochemical features, in the context of food geographical traceability. A correct approach to sampling procedure is always a critical issue in scientific investigation. In particular, in food geographical...
A novel microextraction technique, named in-situ metathesis reaction, combined with ultrasound-assisted ionic liquid dispersive liquid–liquid microextraction was developed for the determination of five phenylurea pesticides (i.e., diuron, diflubenzuron, teflubenzuron, flufenoxuron, and chlorfluazuron) in environmental water samples. In the developed method, 360μL LiNTf 2 aqueous solution (0...
An inter-laboratory exercise was organized under the PHARMAS EU project, by the Advanced School of Public Health (EHESP), in order to evaluate the performances of analytical methods for the measurement of antibiotics in waters (surface and tap). This is the first time such an exercise on antibiotics has been organized in Europe, using different kinds of analytical methods and devices. In this exercise...
Soil quality assessment (SQA) calls for rapid, simple and affordable but accurate analysis of soil quality indicators (SQIs). Routine methods of soil analysis are tedious and expensive. Energy dispersive X-ray fluorescence and scattering (EDXRFS) spectrometry in conjunction with chemometrics is a potentially powerful method for rapid SQA. In this study, a 25mCi 109 Cd isotope source XRF spectrometer...
An analytical method for the determination of the composition of renal stones by capillary isotachophoresis with conductometric detection was developed. Using different leading/terminating electrolyte systems, the qualitative and quantitative analysis of organic compounds (urate, xanthate, oxalate) and inorganic ions (phosphate, Ca 2+ , Mg 2+ , Na + , NH 4+ ) species...
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