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81.
Prussian blue nanoparticles (PBNPs) were prepared by a self‐assembly process on a glassy carbon electrode (GCE) modified with poly(o‐phenylenediamine) (PoPD) film. The stepwise fabrication process of PBNP‐modified PoPD/GCE was characterized using scanning electron microscopy and electrochemical impedance spectroscopy. The prepared PBNPs showed an average size of 70 nm and a homogeneous distribution on the surface of the modified electrode. The PBNPs/PoPD/GCE showed electrocatalytic activity towards the oxidation of pyridoxine (PN) and was used as an amperometric sensor. The modified electrode exhibited a linear response for PN oxidation over the concentration range 3–38.5 μM with a detection limit of ca 6.10 × 10?7 M (S/N = 3) and sensitivity of 2.79936 × 103 mA M?1 cm?2 using an amperometric method. The mechanism and kinetics of the catalytic oxidation reaction of PN were investigated using cyclic voltammetry and chronoamperometry. The values of α, kcat and D were estimated as 0.36, 1.089 × 102 M?1 s?1 and 8.9 × 10?5 cm2 s?1, respectively. This sensor also exhibited good anti‐interference and selectivity. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Mir Ali Farajzadeh Saheleh Sheykhizadeh Parisa Khorram 《Journal of separation science》2013,36(5):939-946
In this study a simple and rapid sample preparation technique, homogeneous liquid–liquid extraction based on phase separation in the presence of a salt performed in a narrow‐bore tube, followed by GC‐flame ionization detection has been developed. In this work, sodium chloride and ACN were used as the salting‐out agent and water‐soluble extraction solvent, respectively. The homogeneous solution of water and ACN was broken by addition of the salt. Small volume of ACN was collected on top of the tube and the extracted analytes in the collected phase were determined. It has been successfully used for the analysis of five phthalate esters as model compounds in aqueous sample. Experimental parameters affecting the extraction efficiency such as kind and volume of the water‐soluble organic solvent, length and diameter of the tube, and pH of the sample solution were investigated. Under the optimal conditions, the LODs were between 0.02 and 0.7 μg/L and enrichment factors were in the range of 172–309. In addition, good linearity (between 1 and 5000 μg/L) and high precision on the base of RSD (<8%, C = 600 μg/L, n = 6) were achieved. 相似文献
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This work proposes a novel biomimetic sensor for the potentiometric transduction of rivastigmine based on molecularly imprinted polymer (MIP). Using the Taguchi method, this study analyzed the optimum conditions for preparing the MIP‐based membranes. The rank order of each controllable factor was also determined. MIP‐based membranes exhibited a Nernstian response (30.7±1.1 mV decade?1) in a concentration range from 1.0×10?5 to 1.0×10?2 mol L?1 with a LOD of 6.3×10?6 mol L?1. The sensor was successfully applied to the determination of rivastigmine concentrations in human serum, plasma, urine, rat brain and tablets. 相似文献
86.
Commercialized rapid immunoanalytical tests for determination of allergenic food proteins: an overview 总被引:1,自引:0,他引:1
Patricia Schubert-Ullrich Judith Rudolf Parisa Ansari Brigitte Galler Manuela Führer Alexandra Molinelli Sabine Baumgartner 《Analytical and bioanalytical chemistry》2009,395(1):69-81
Food allergies have become an important health issue especially in industrialized countries. Undeclared allergenic ingredients
or the presence of “hidden” allergens because of contamination during the food production process pose great health risks
to sensitised individuals. The EU directive for food labelling lists allergenic foods that have to be declared on food products
by the manufacturers. The list includes gluten-containing cereals, crustaceans, eggs, fish, peanuts, soybeans, milk, various
nuts (e.g. almond, hazelnut, and walnut, etc.), celery, mustard, sesame seeds, lupin, and molluscs. Reliable methods for detection
and quantification of food allergens are needed that can be applied in a fast and easy-to-use manner, are portable, and need
only limited technical equipment. This review focuses on the latest developments in food allergen analysis with special emphasis
on fast immunoanalytical methods such as rapid enzyme-linked immunosorbent assays (ELISA), lateral-flow immunochromatographic
assays (LFA) and dipstick tests. Emerging technologies such as immunochemical microarrays and biosensors are also discussed
and their application to food allergen analysis is reviewed. Finally, a comprehensive overview of rapid immunochemical test
kits that are currently available commercially is given in tabular form. 相似文献
87.
Alireza Pourhossein Masoud Madani Mohsen Shahlaei Kambiz Fakhri Parisa Alimohamadi Maryam Amiri 《Central European Journal of Chemistry》2009,7(3):382-387
A sensitive, simple and rapid method for ultra-trace determination of iron and manganese based on ultrasound assisted pseudodigestion
in citric acid fermentation medium samples (beet and cane molasses and raw sugar based mediums) is described. Parameters influencing
pseudo-digestion, such as sonication time, sample mass and solvent system were fully optimized. Final solutions obtained upon
sonication were analyzed by electrothermal atomic absorption spectrometry (ETAAS). The best conditions for metal pseudo-digestion
were as follows: a 25, 30 and 20 min sonication time for beet molasses, cane molasses and raw sugar based medium samples,
respectively, 0.7 g sample mass of raw sugar based samples, 0.5 g sample mass of molasses based samples and an extraction
mixture of concentrated HNO3-H2O2, in 25 mL of solvent. Analytical results obtained for the two metals by ultrasound assisted pseudo-digestion and conventional
wet digestion methods showed a good agreement. This method reduces the time required for all treatments (heating to dryness,
cooling and separation) in comparison with conventional wet digestion method. The accuracy of the method was tested by comparing
the obtained results with that of conventional wet digestion method.
相似文献
88.
Akbar Golchin Parisa Rezaei Hossein Mohammadzadeh 《Czechoslovak Mathematical Journal》2009,59(3):595-611
By a regular act we mean an act such that all its cyclic subacts are projective. In this paper we introduce strong (P)-cyclic property of acts over monoids which is an extension of regularity and give a classification of monoids by this property
of their right (Rees factor) acts. 相似文献
89.
Hassan Keypour Nasibeh Rahpeyma Parisa Arzhangi Majid Rezaeivala Yalcin Elerman Orhan Buyukgungor Laura Valencia 《Polyhedron》2010
Two macrocyclic Schiff base ligands, L1 [1+1] and L2 [2+2], have been obtained in a one-pot cyclocondensation of 1,4-bis(2-formylphenyl)piperazine and 1,3-diaminopropane. Unfortunately, because of the low solubility of both ligands, their separation was unsuccessful. In the direct reaction of these mixed ligands (L1 and L2) and the appropriate metal ions only [CoL1(NO3)]ClO4, [NiL1](ClO4)2, [CuL1](ClO4)2 and [ZnL1(NO3)]ClO4 complexes have been isolated. All the complexes were characterized by elemental analyses, IR, FAB-MS, conductivity measurements and in the case of the [ZnL1(NO3)]ClO4 complex with NMR spectroscopy. 相似文献
90.
Sargassum oligocystum (Heterokontophyta) is one of the most abundant algae distributed in the Persian Gulf. In this study, the cytotoxic effects of this algae on brine shrimp larvae were evaluated and the main sterols of the algae identified. Separation and purification of the compounds was carried out using silica gel column chromatography and HPLC to obtain eight pure compounds, 1-8. Structural elucidation of the constituents was based on the data obtained from (1)H-NMR, (13)C-NMR, HSQC, HMBC, DEPT and EI-MS. The compounds separated from S. oligocystum were identified as 22-dehydrocholesterol (1), cholesterol (2), fucosterol (3), 29-hydroperoxystigmasta-5,24(28)-dien-3β-ol (4), 24-hydroperoxy-24-vinylcholesterol (5), a mixture of 24(S)-hydroxy-24-vinylcholesterol (6) and 24(R)-hydroxy-24-vinylcholesterol (7), and ostreasterol (8) based on their spectral data and from comparison with those previously reported in the literature. 相似文献