Electro-generated Chemiluminescent Determination of Methotrexate in Pharmaceutical Preparations by Tris (2,2-bipyridine)ruthenium(II) Using Flow Injection

A novel electro-generated chemiluminescence method for the determination of methotrexate (2,4-diamino-N10-methyl pteroyl glutamic acid) in pharmaceutical formulations is proposed. The method was based on the chemiluminescence (CL) emission intensity produced as a result of the electrochemical oxidation of the nbspinto the active nbspform, which then reacts with the methotrexate and produces light.nbspReaction variables were thoroughly investigated. The optimum conditions were incorporated in the procedure. Linear calibration curve were obtained for signal in mV versus concentration in mol L1 in the range 0-21times107 M with percentage relative standard deviation of less than 2% (n = 6) and correlation coefficient of r = 0.99986. The method described here proved to be very convenient and easy to use for the assay of methotrexate in drug formulations. This method was tested by the determination of methotrexate in different drugs containing known concentration

Preparation of Magnetite Nanoparticles Filters for the Removal of Benzene from Drinking Water

A simple method was described for the synthesis of magnetite nanoparticles by mixing and sterring two equivalents of iron(II) chloride tetrahydrate with three equivalent of iron(III) chloride hexahydrate in the presence of ammonium hydroxide. The precipitated magnetite nanoparticles were washed with 5% NH4OH. The nanoparticles formed were characterized by IR, SEM and X-ray diffraction and then applied for the removal of benzene from water samples

Colorimetric Determination of Indole using 2,4,6-trimethoxybenzaldehyde

Indole is an aromatic heterocyclic organic compound. The indole nucleus is very important for many natural and synthetic molecules with significant biological activity. Compounds that contain an indole ring are called indoles. Indoles are an important class of heterocycles not only because they are among the most ubiquitous compounds in nature, but also because they have a wide range of biological activities. 2,4,6-Trimethoxybenzaldehyde can be used as antibacterial synergist.nbsp When indole was mixed with 2,4,6-trimethoxybenzaldehyde at room temperature, no color was observed. However in the presence of concentrated hydrochloric acid, a brown red complex is formed which has a maximum absorbance at 488 nm. The parameters affecting this reaction were studied in order to find the suitable conditions for the reaction to complete. The effect of the acid concentration, the reaction temperature and the amount of the reagent on the determination of indole- 2,4,6-trimethoxybenzaldehyde complex were investigated. The system requirements and the best conditions for complete determination are sequently studied. At the optimal conditions, 0.02% w/v 2,4,6-trimethoxybenzaldehyde, 4M HCl at 60oC, were used for the determination of indole , At these conditions, it was found that the absorbance is directly related to the concentration of indole. Different concentrations of indole over the range from 0.25-1 mug ml-1 were reacted with the reagent. The detection limit (signal : noise 3:1) was 0.02 microg ml-1 and the correlation coefficient was 0.995, Linearity was obtained with slope equals 0.608and the intercept equals 0.000.

Emitting species in chemiluminescence reactions with acidic potassium permanganate : a re-evaluation based on new spectroscopic evidence

The reaction of acidic potassium permanganate with a wide range of compounds is known to produce a broad red emission, and there is strong evidence for an excited manganese(II) emitting species. Nevertheless, numerous researchers have proposed other emitters for reactions with acidic potassium permanganate, particularly for systems where fluorescent compounds were present, either as enhancers or reaction products. We have examined many reactions of this type and found that, in most cases, the same red emission was produced. There were, however, some exceptions, including the oxidation of dihydralazine, certain thiols and sulphite (each in the presence of an enhancer).<br /