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A novel hybrid material (SBA-P1) is prepared through the functionalization of mesoporous silica (SBA-15) with a 1,8-naphthalimide-based dye by sol–gel reaction. The characterization results of elemental analysis (EA), X-ray powder diffractometer (XRD) and spectroscopic methods demonstrate the fluorescence dye P1 is successfully grafted onto the inner surface of SBA-15 and the organized structure is...
In measuring specific conditions in the real world, there are many situations where both the oxygen concentration and the temperature have to be determined simultaneously. Here we describe a dual optical sensor for oxygen and temperature that can be adapted for different applications. The measurement principle of this sensor is based on the luminescence decay times of the oxygen-sensitive ruthenium...
A new methodology was developed for the determination of ultratrace levels of gold in water samples, soils and river sediments. Dispersive liquid–liquid microextraction was used to preconcentrate the ion pair formed between AuCl 4− and [CH 3 (CH 2 ) 3 ] 4 N + in a microliter-range volume of chlorobenzene using acetone as disperser solvent. When...
Poly(glycidyl methacrylate) cation exchange monolithic column was prepared in fused-silica capillaries of 320μm i.d. by thermally initiated radical polymerization and utilized in capillary ion chromatography. With 15mM methanesulfonic acid as the mobile phase, the separations of a mixture of inorganic cations (Li + , Na + , NH 4+ , K + ) was tested by using a capacitively...
We describe a novel, cost effective and simple technique for the manufacture of high sensitivity absorption cells for microfluidic analytical systems. The cells are made from tinted polymethyl methacrylate (PMMA) in which microfluidic channels are fabricated. Two windows (typically 250μm thick, resulting in little optical power loss) are formed at either end of the channel through which light is coupled...
In this paper, cyclodextrin–graphene hybrid nanosheets (CD–GNs) for the first time have been used as an enhanced material for ultrasensitive detection of carbendazim by electrochemistry method. The peak currents of carbendazim on the GNs modified glassy carbon electrode (GNs/GCE) and the CD–GNs/GCE are increased by 11.7 and 82.0 folds compared to the bare GCE, respectively. This indicates the nanocomposite...
Enhancing the flowing properties of fresh concrete is a crucial step for cement based materials users. This is done by adding polymeric admixtures. Such additives have enabled to improve final mechanicals properties and the development of new materials like high performance or self compacting concrete. Like this, the superplasticizers are used in almost cement based materials, in particular for concrete...
A sensitive reagent-injection flow analysis method for the spectrophotometric determination of nitrate in marine, estuarine and fresh water samples is described. The method is based on the reduction of nitrate in a micro column containing zinc granules at pH 6.5. The nitrite formed is reacted with sulfanilamide and N-(1-naphthyl)ethylene diamine (Griess reagent), and the resulting azo compound is...
A new sensor for an amplified electrochemical detection of carbohydrates is proposed, where carbohydrates are oxidized by CNT–NiCo-oxide composite in basic solutions. Cyclic voltammograms of the modified electrode show a stable and well defined redox couple in alkaline media due to the synergy of Ni(II)/Ni(III) system with Co(II)/Co(III). The modified electrode shows excellent electrocatalytic activity...
Representing a compound by a numerous structural descriptors becomes common in quantitative structure–activity relationship (QSAR) studies. As every descriptor carries molecular structure information more or less, it seems more advisable to investigate all the possible descriptor vectors rather than traditional variable selection when building a QSAR model. Based on particle swarm optimization (PSO)...
Sudan I monoclonal antibodies (Mabs) were prepared by hybridoma technique and firstly used to develop a Sudan I immunosensor by immobilizing the Mabs on a gold electrode. o-Mercaptobenzoic acid (MBA) was covalently conjugated on the gold electrode to form a self-assembled monolayer (SAM). The immobilization of Sudan I Mabs to the SAM was carried out through a stable acyl amino ester intermediate generated...
Novel immunomagnetic particles have been prepared for separation of CD4 + lymphocytes. The magnetic nanoparticles with a diameter of approximately 5–6nm were first synthesized by co-precipitation from ferrous and ferric iron solutions and subsequently encapsulated with poly(glycidyl methacrylate) (PGMA) by precipitation polymerization. Monoclonal antibody specific to CD4 molecules expressed...
We reported a rapid toxicity assay method using electrochemical biosensor for pesticides, Escherichia coli (E. coli) was taken as a model microorganism for test. In this method, we adopted ferricyanide instead of natural electron acceptor O 2 , and then microbial oxidation was substantially accelerated. Toxicity assays measured the effect of toxic materials on the metabolic activity of microorganisms...
A novel solid-phase microextraction (SPME) fiber coated with multiwalled carbon nanotubes/polypyrrole (MWCNTs/Ppy) was prepared with an electrochemical method and used for the extraction of pyrethroids in natural water samples. The results showed that the MWCNTs/Ppy coated fiber had high organic stability, and remarkable acid and alkali resistance. In addition, the MWCNTs/Ppy coated fiber was more...
A new ionic liquid (IL) based solid-phase microextraction (SPME) fiber was investigated and used for headspace (HS) extraction of methyl tert-butyl ether (MTBE) in a gasoline sample. Using the new IL coated HS-SPME fiber with the combination of gas chromatography–flame ionization detection (GC–FID); sub-to-low μgL −1 concentrations of MTBE were detected. Four different ILs including 1-butyl-3-methylimidazolium...
A novel simultaneous cloud point extraction method for the determination of carmoisine and brilliant blue FCF by spectrophotometry has been developed. The method is based on the cloud point extraction of carmoisine and brilliant blue FCF from aqueous solution using Triton X-100, diluting the extracted surfactant rich phase with water and measuring the absorbance at 522 and 640nm for carmoisine and...
In this work, chromatographic separation of niacin and niacinamide using pure water as the sole component in the mobile phase has been investigated. The separation and analysis of niacinamide have been optimized using three columns at different temperatures and various flow rates. Our results clearly demonstrate that separation and analysis of niacinamide from skincare products can be achieved using...
Total Reflection X-ray Fluorescence (TXRF) is a well-established technique for chemical analysis, but it is mainly employed for quality control in the electronics semiconductor industry. The capability to analyze liquid and uniformly thin solid samples makes this technique suitable for other applications, and especially in the very critical field of environmental analysis. Comparison with standard...
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