Knovenagel reaction of barbituric acid with different aldehydes were used to synthesize new barbiturates.This is a novel method which can be used to synthsis various types of new generation of barbiturates which are different from the previously reported.
Teucrium polium is a dwarf sub-shrub usually 30-60 cm high with many branches, which is fairly distributed throughout Iran, with its flowering being season mainly from April to July. The plant was collected during its flowering season in Baghmalek region in the North-East of Khuzestan province, Iran. After the identification of the genus, species and variety of the plant, the dried whole plant (flowers, fruits and the leaves) was steam distilled with different methods. The isolated essential oil was dried over anhydrous sodium sulphate and stored at 4-6 ℃. Analysis of the essential oil was carried out by GC-MS technique. At least 10 major components were identified (3-carene/α-pinene, β-phellandrene, limonene, germacrene, β-bourbonene, β-caryophylene, γ-muurolene, γ-elemene, spathulenol, β-eudesmol) (totally 97.02%). Also, successive TLC and column chromatography of the essential oil resulted in the separation of four fractions. Based upon 1 H NMR, IR and mass spectra, the fractions with R f =0.12 and 0.93 were determined as guaiol and a mixture of α-pinene, β-phellandrene and limonene, respectively.
Penicillin has been the most widely used antibiotic for many grampositive bacterial infections. In this research the purity of the standard active ingredients of the various dosage forms of three penicillins (Amoxicillin, Cloxacillin and Ampicillin) imported and the purity percentage of the active ingredients in each of the various dosage forms of these drugs manufactured by several pharmaceutical companies of Iran (Kosar, Farabi and Jaber Ibn Hayan) were investigated and determined by HPLC technique. The analyses were made by using a Knauer (Germany) Spherimage-80, ODS, 2-5 µm C 18 column with 30 cm length, and i.d. 4.5 mm. A 20 µL solution from each individual sample and the standard solution were injected separately onto the column of an HPLC instrument which was equipped with ECW 2000 software of Knauer, Germany. The results obtained in this research have shown that the purity percentage of the active ingredients of the standard powder and the various dosage forms of all the drugs used, were 100%.
This work reports the construction and characterization of plastic electrochemical micro-flow-cells with integrated injection-moulded polymer electrodes. The three electrodes (working, auxiliary, and reference) were fabricated by injection-moulding from a conducting grade of polystyrene loaded with carbon fibers. On-chip reference electrodes were prepared by coating one of the conducting polymer electrodes with a Ag/AgCl layer (implemented either by ebeam evaporation of Ag followed by electrochemical formation of AgCl or by applying a Ag/AgCl paste). Working electrodes were either polymer electrodes coated with Au by e-beam evaporation or bare conducting polymer electrodes. The electrodes were integrated into the micro-flow-cells by an over-moulding process followed by ultrasonic welding. The devices were characterized by optical and electrochemical techniques. Studies by cyclic voltammetry (CV), anodic stripping voltammetry (ASV) and electrochemiluminescence (ECL) demonstrate proofof-principle of the micro-flow-cells as electrochemical sensors. The use of microfabrication technologies, especially when applied to polymeric materials, enable the mass fabrication of small, reproducible, low-cost, portable and disposable sensors [1]. In particular, the integration of electrochemical analysis techniques into microfluidic devices is an area of increasing interest [2 -4]. The high sensitivity and selectivity of electrochemical detection coupled with simple, compact and inexpensive instrumentation and low power requirements make electroanalysis highly amenable to miniaturization.Following the recent trend to replace glass with polymers as the substrate of microfluidic devices, imprinting and hot embossing are the most common microfabrication processes [1]. However, injection-moulding offers some advantages as an alternative fabrication process: in addition to providing planar structures (such as channels) quickly and at a reasonable cost, it allows one to create three-dimensional structures and to embed preformed elements (such as electrodes) into the plastic during the moulding process. This feature is important since the significance of integrated microfluidic devices (combining fluidic handling, sensing and transduction elements) in a single chip is increasing [5].Reports of miniaturized flow devices with electrochemical detection cover a variety of applications [6 -11]. In particular, miniaturized flow cells for electrochemical stripping analysis [12 -17] and microfabricated cells for electrogenerated chemiluminescence (ECL) detection have been the subject of numerous reports [18 -21]. Although the use of injection-moulding has been reported for the fabrication of plastic microdevices for isotachophoresis electroseparations with integrated polymer electrodes for the control of the separation potential and for performing conductivity detection [22], to our knowledge, there are no reports of injection-moulded fluidic devices for voltammetric and electrochemiluminescence detection. This communication reports t...
Catalytic adsorptive stripping voltammetry (CAdSV) has been demonstrated at a bismuth film electrode (BiFE) in an injection-moulded electrochemical micro-flow cell. The polystyrene three-electrode flow cell was fabricated with electrodes moulded from a conducting grade of polystyrene containing 40% carbon fibre, one of which was precoated with Ag to enable its use as an on-chip Ag/AgCl reference electrode. CAdSV of Co(II) and Ni(II) in the presence of dimethylglyoxime (DMG) with nitrite employed as the catalyst was performed in order to assess the performance of the flow cell with an in-line plated BiFE. The injectionmoulded electrodes were found to be suitable substrates for the formation of BiFEs. Key parameters such as the plating solution matrix, plating flow rate, analysis flow rate, solution composition and square-wave parameters have been characterised and optimal conditions selected for successful and rapid analysis of Co(II) and Ni(II) at the ppb level. The analytical response was linear over the range 1 to 20 ppb and deoxygenation of the sample solution was not required. The successful coupling of a microfluidic flow cell with a BiFE, thereby forming a "mercury-free" AdSV flow analysis sensor, shows promise for industrial and in-the-field applications where inexpensive, compact, and robust instrumentation capable of low-volume analysis is required.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.