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NMR spectroscopy was employed for the detection of adulteration of refined olive oil with refined hazelnut oil. Fatty acids and iodine number were determined by 1 H NMR, whereas 31 P NMR was used for the quantification of minor compounds including phenolic compounds, diacylglycerols, sterols, and free fatty acids (free acidity). Classification of the refined oils based on their fatty...
In the present work, the applicability of thin mercury film on a rotating disk electrode (TMF-RDE), to assess the free metal ion concentration by the absence of gradients and Nernstian equilibrium stripping (AGNES), is evaluated. The thickness of the mercury film and several AGNES parameters has been optimized. A nominal 16nm film is chosen due to the higher signal (faradaic current) relative to the...
Multivariate spectral analysis has been widely applied in chemistry and other fields. Spectral data consisting of measurements at hundreds and even thousands of analytical channels can now be obtained in a few seconds. It is widely accepted that before a multivariate regression model is built, a well-performed variable selection can be helpful to improve the predictive ability of the model. In this...
We describe the procedure developed for the simultaneous detection and quantification of angiotensin II and angiotensin-(1-7), by capillary zone electrophoresis with UV detection by photodiode-array, at a wavelength of 200nm, in the plasma and urine from hypertensive rats. Optimal separation was achieved with a 100mM boric acid+3mM tartaric acid+10fM gold (III) chloride electrolyte solution at pH...
In this paper, a kind of β-amyloid peptide (Aβ1–16) conjugated gold nanoparticles (Aβ1–16@GNPs) are prepared and employed as colorimetric indicator for studying the interaction of β-amyloid peptide with metallic ions (e.g. Zn 2+ and Ca 2+ ). In the presence of Zn 2+ , mono-dispersing Aβ1–16@GNPs enable to form aggregates or attach on the SHG-44 (human glioma cell) cellular...
A novel electrochemical biosensor is described for detection of breakpoint cluster region gene and a cellular abl (BCR/ABL) fusion gene in chronic myelogenous leukemia (CML) by using thiolated-hairpin locked nucleic acids (LNA) as the capture probe. The hairpin LNA probe was immobilized on the nanogold (NG)/poly-eriochrome black T (EBT) film-modified glassy carbon electrode (GCE). The immobilized...
The Sonogel electrode was immersed in hemin solution to obtain the hemin–Sonogel-modified electrode by cyclic voltammetry (CV). It was applied to detect superoxide radicals produced by xanthine oxidase catalyzed hypoxanthine oxidation. The characterization of hemin–Sonogel was modified by impedance and CV.
This work exploited a sequential injection lab-on-valve (LOV) system for the determination of cadmium by anodic stripping voltammetry (ASV). A miniaturized electrochemical flow cell (EFC) was fabricated in LOV, in which a nafion coated bismuth film electrode was used as working electrode. The cadmium was electrodeposited on the electrode surface in bismuth solution, and measured with the subsequential...
Speciation analysis of aluminium in the presented system of HPLC–FAAS hyphenated technique lasts 4min. Using the bifunctional column in model analysis and using the calculation methods for modelling using the Mineql program enabled the authors to presume that particular forms will be subjected to elution in the following order: (1) AlF 2+ and AlF 4− , (2) AlF 2+ and...
A method based on solid-phase microextraction (SPME) followed by gas chromatography with microwave-induced plasma atomic emission detection for determining dimethylselenide (DMSe) and dimethyldiselenide (DMDSe) in milk and milk by-products is proposed. Parameters affecting the SPME, such as sample volume or mass, ionic strength, adsorption and desorption times and temperatures were optimized in the...
A microwave-assisted extraction used to extract trace triorganotin from aquatic organisms and a sensitive analytical method for the determination of ultratrace triorganotin (namely trimethyltin, triethyltin, tripropyltin and tributyltin) with capillary electrophoresis–inductively coupled plasma mass spectrometry were firstly described in this study. The extraction method is simple, effective and can...
An aptamer-based assay for thrombin with high specificity and sensitivity was presented. In the protocol, the aptamer for thrombin was immobilized on magnetic nanoparticle, and its complementary oligonucleotide was labeled with gold nanoparticles, then the aptamer was hybridized with the complementary oligonucleotide to form the duplex structure as a probe, this probe could be used for the specific...
CdTe quantum dots (QDs), capped with mercaptopropionic acid (MPA), were synthesized and the variation of their fluorescence properties (steady state and lifetime) with pH was assessed in solution and when immobilized in a sol–gel host. Three different sizes of CdTe QDs with excited state lifetimes ranging from 42 to 48ns and with emission maximum at 540nm (QD 540 ), 580nm (QD 580 )...
In this paper a carbon ionic liquid electrode (CILE) was fabricated by using ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM]EtOSO 3 ) as modifier and further gold nanoparticles were in situ electrodeposited on the surface of CILE. The fabricated Au/CILE was used as a new platform for the immobilization of hemoglobin (Hb) with the help of a Nafion film. Electrochemical experimental...
The combination of molecular imprinting and solid-phase microextraction (SPME) technique provides a powerful sample preparation tool in terms of selectivity, simplicity, and flexibility. This paper reports a novel molecularly imprinted polymer (MIP) coated SPME fiber with 17β-estradiol as template by improved multiple co-polymerization method. The obtained fiber exhibits excellent characteristics...
Vapor generation-inductively coupled plasma-optical emission spectrometry was used for the determination of sulfide in water samples preserved by the addition of a zinc acetate and sodium hydroxide solution. Hydrogen sulfide and acid-volatile sulfides were transformed, by acidification, to a gaseous phase in a vapor generator and subsequently detected by inductively coupled plasma optical emission...
A novel fluorescence turn-on detection method of human serum albumin (HSA) and bovine serum albumin (BSA) in aqueous solution is investigated using 2,4-dihydroxyl-3-iodo salicylaldehyde azine (DISA). Upon the addition of DISA to HSA/BSA solution, a fluorescence turn-on effect at 529nm can be observed with a large stokes shift of ∼129nm based on hydrophobic binding-mode between protein and dye. Under...
A sensitive and fast responding electrochemical sensor is described for the determination of free and total sulphur dioxide in wines and grape juices which prevents interferences coming from ethanol and other natural components. It consists of a cell provided with a porous gold working electrode supported on one face of an ion-exchange membrane, acting as a solid polymer electrolyte (SPE), which allows...
A nitrite sensor based on immobilized Dawson-type tungstophosphate α-K 7 [H 4 PW 18 O 62 ]·18H 2 O (PW 18 ) in multilayers of charged polyelectrolyte poly(allylamine hydrochloride) (PAH) on a glassy carbon electrode is described. A nitrite sensor manufactured with 10 layers has a sensitivity of ∼4nA/μM nitrite, fast response time (<6s), low detection...
A number of recent studies have utilised ferricyanide as a respiratory mediator for microbial-based assays for determining water quality parameters such as biochemical oxygen demand (BOD) and toxicity. The majority of assays published to date obtain a result by determining the difference in ferrocyanide accumulation between a test sample and one or more control samples. However, a validation of the...
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