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The elemental composition of seasoning products, like spices garlic and onion, has been reviewed paying special attention to methods proposed in the literature to determine specific elements or as much as possible components of these products which are widespread used in food preservation or food flavouring and can contribute to the intake of both, essential and toxic elements. Sample treatment and...
A highly selective and sensitive rhodamine-based colorimetric chemosensor (1) for quantification of divalent copper in aqueous solution has been investigated in this work. It was designed using salicylaldehyde hydrazone and rhodamine 6G as copper-chelating and signal-reporting groups, respectively. In environmentally friendly media (50%(v/v) water/ethanol and 10mM NaAc–HAc neutral buffer (pH 7.0)),...
The properties and behaviour of Hg depend on both the oxidation state and the chemical form: the bioavailability, toxicity, persistence and accumulation of mercury in the food web are strongly influenced by chemical speciation. The present work aims to determine the chemical forms of mercury present in soil and to evaluate the fraction of mercury in soil solution available to plants. In order to do...
Calcein was found to be able to use as chemiluminescence reagent and post-chemiluminescence was observed when fenfluramine was injected into the mixture after the CL reaction of calcein–potassium permanganate. Based on this phenomenon, a flow injection CL method was established for the determination of fenfluramine. The possible CL mechanism was proposed. The CL intensity was correlated linearly with...
A procedure for rapid quantitative analysis of pharmaceutical powders is described. Powdered samples were measured in a rotating cell in order to avoid sub-sampling problems by increasing the irradiated area. Quantitative determination of sulfathiazole and sulfanilamide, using a simple univariate calibration model is proposed. Even though both antibacterials are of the same chemical family (sulfonamides),...
The voltammetric assay of Cu(II) was investigated using a carbon nanotube electrode (CNE) and fluorine immobilized onto a carbon nanotube electrode (FCNE) in cyclic voltammetry (CV), square-wave (SW) stripping voltammetry, and chronoamperometry. Optimum SW conditions were attained at working ranges of 0.01–0.11ngL −1 Cu(II) (11 points), and a relative standard deviation of 1.68% (RSD, n=15)...
Dehydroandrographolide, andrographolide and geniposide are the main active constituents of many herbal medicines, e.g., Fructus gardeniae, Common Andrographis Herb. They are used as the markers to control the quality of such herbal medicines and their herbal preparations. In this paper, a simple and sensitive high-performance liquid chromatographic (HPLC) method coupled with photodiode array detection...
Stir bar sorptive extraction and liquid desorption followed by high performance liquid chromatography with diode array detection (SBSE-LD-LC-DAD) is proposed for the determination of triclosan in personal care products, biological and environmental matrices, which is included in the priority lists, set by several international regulatory organizations. Instrumental conditions and experimental parameters...
This work reports the development of a simple, robust, automated sequential injection analysis (SIA) system for the enzymatic determination of total (tGSH) and oxidized (GSSG) glutathione in human whole blood. The reduced (GSH) glutathione concentration is then obtained as the difference between the tGSH and GSSG concentrations. The determination was based on the DTNB–GSSG reductase recycling assay,...
A new method for F AAS determination of sodium and potassium in biodiesel using water-in-oil microemulsion as sample preparation is proposed. The method was investigated for biodiesel produced from different sources, as soybean, castor and sunflower oil and animal fat and was also applied for vegetable oils. The optimized condition for microemulsion formation was 57.6% (w/w) of n-pentanol, 20% (w/w)...
A new multi-residue method for the determination of 25 acidic/neutral pharmaceuticals (antibiotics, anti-inflammatory/analgesics, lipid regulating agents, diuretics, triazides, H2-receptor antagonists, cardiac glicozides and angiotensin II antagonists) and personal care products (sunscreen agents and preservatives) in surface water with the usage of a new technique: ultra performance liquid chromatography–negative...
A novel, sensitive electrochemical immunoassay in a homogeneously dispersed medium is described herein based on the unique features of agarose beads and the special amplified properties of biometallization. The immunochemical recognition event between human immunoglobulin G (IgG) and goat anti-human IgG antibody is chosen as the model system to demonstrate the proposed immunoassay approach. Avidin-agarose...
A novel conductive biocomposite film (MWCNTs–DNA–cyt c) which contains multi-walled carbon nanotubes (MWCNTs) along with the incorporation of DNA and cytochrome c (cyt c) has been synthesized on glassy carbon electrode (GCE), gold (Au), indium tin oxide (ITO) and screen printed carbon electrode (SPCE) by potentiostatic methods. The presence of both MWCNTs and DNA in the biocomposite film enhances...
This work reports on the electrocatalytic oxidation of hydroxide using different central metal ion phthalocyanines and porphyrins immobilized on gold electrodes. The apparent electrocatalytic activity of cobalt phthalocyanine or porphyrin modified electrodes was found to be the greatest among the present series of metal ion macrocycles investigated. Copper and unmetallated phthalocyanine or porphyrin...
T-2 and HT-2 toxins are Fusarium mycotoxins that can occur in cereals and cereal-based products. Three fluorescent labeling reagents, i.e. 1-naphthoyl chloride (1-NC), 2-naphthoyl chloride (2-NC) and pyrene-1-carbonyl cyanide (PCC), were used for the determination of T-2 and HT-2 toxins by high-performance liquid chromatography (HPLC) with fluorescence detection (FD). Pre-column derivatization of...
Membranes for preconcentration of molecular iodine were developed by two different routes: (i) UV-grafting of 1-vinyl-2-pyrrolidone in the pores of microporous poly(propylene) host membrane (grafted membrane), and (ii) physical immobilization of preformed poly(vinylpyrrolidone) (PVP) in a plasticized cellulose triacetate matrix to form the polymer inclusion membrane (PVP-PIM). The UV-grafted PVP-membrane...
We successfully determined the molecular structure of peroxycitric acid (PCA) coexisting in the aqueous equilibrium mixture with citric acid (CA; 1,2,3-tricarboxylic-2-hydroxy propane) and hydrogen peroxide (H 2 O 2 ) by a combined use of reversed-phase HPLC (RP-HPLC), potentiometric, hydrodynamic chronocoulometric (HCC) and electrospray ionization mass spectroscopic (ESI-MS) methods...
A new method of dispersive liquid phase microextraction (DLPME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for the determination of trace Co and Ni using 1-(2-pyridylazo) 2-naphthol (PAN) as chelating reagent. Several factors influencing the microextraction efficiency of Co and Ni and their subsequent determinations, such as pH, extraction and disperser solvent...
A novel phenylhydrazone-based indole anion receptor is synthesized by a simple method, and the receptor binds acetate anions with good selectivity in DMSO solution, which is related to the structure of the receptor matching with the anion. The binding properties of the host are examined by UV–vis changes. The color changes of the host upon the addition of a variety of structurally different anions...
This study describes interaction mechanism between menadione and the yeast with the aid of the catabolite assay and the culture fluorescence method, with a view towards exploitting the potential of the mediator in toxicology study. Double mediator system containing menadione and the hydrophilic mediator, ferricyanide, was employed for evaluating the toxic effects of furfural on the yeast and the results...
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