Preparation and characterization of some phosphoborosilicate glasses containing some micronutrients as plant fertilizers

Four phosphoborosilicate glasses containing one or more of the micronutrients: namely Cu, Zn, Fe, were prepared using analytical grade chemicals by melting in an electric furnace at about 1400°C for 2hr. The melts being calcined at about 450°C, were carefully crushed to grains of 2mm size. The release rate of the glass grains of 2mm size in 0.4%HC1 solution, 2% citric acid solution, and distilled water at room temperature was determined using a standard grain method for immersion time intervals varying between 1 to 4 weeks. The concentrations of K and P ions released into the leaching solutions were determined. The results obtained revealed that some of the prepared plant fertilizer samples led to a significant increase in the plant growth better than that observed in case of the traditional fertilizers. Furthermore, the extents of K and P ions released increased by increasing the time of immersion

Titrimetric and spectrophotometric titration of some pharmaceutical important thiol compounds using 2,6-dichlorophenol-indophenol

Two procedures were adopted for determination of three pharmaceutical compounds containing thiol group; namely, D-penicillamine, N-acetylcysteine and captopril, by 2,6-dichlorophenol-indophenol [DCPIP]. In the first, the drugs are treated with a known and excessive volume of 1 x 10-3 M DCPIP and after 5 minutes the surplus is determined by titration with standard L-ascorbic acid. In the second, the drugs are titrated with 5 x 10-4 M solution of DCPIP with spectrophotometric end-point detection. The stoichiometry of the reaction is assumed and a reaction mechanism is suggested. The methods have been applied to the analysis of pharmaceutical preparation containing these drugs and the results obtained compared favorably with those from the pharmacopoeial methods. The methods are simple, accurate and precise

rapid oxidimetric determination of some thioxanthene derivatives using organic brominating agents

A simple titrimetric method was described for rapid determination of three thioxanthene derivatives; namely, chlorprothixene, methixene and thiothixene. The proposed method involved the use of N- bromosuccinimide [NBS] and N-bromophthalimide [NBP] as titrants. The end point was detected visually using methyl red as indicator, and was marked by the disappearance of the red color of the indicator. The stoichiometric ratio of the reaction was assessed and a proposal of the reaction pathway was suggested. The proposed method was applied to the determination of the studied compounds in dosage forms and the results obtained were compared favorably with those given by the official methods

Spectrophotometric determination of captopril in dosage form via charge-transfer complexes

Two simple and sensitive spectrophotometric methods for the assay of captopril have been presented. The first is based on the reaction of captopril with iodine to give a molecular charge-transfer complex. The second method depends on the formation of a highly colored stable radical anion between captopril and 7,7,8,8-tetracyanoquinodimethane [TCNQ] as a pi-electron acceptor. The molecular ratios of the reactants in the complexes as well as the experimental conditions leading to maximum charge-transfer b and s have been studied. Beer's Law is obeyed over captopril concentration range of 2-8 mug.ml -1 by iodine method and 0.32-3.2 mug.ml -1 by TCNQ method. The proposed procedures have been applied successfully to the analysis of captopril tablets and the results are in agreement with those of official methods