Spectrometric, thermal and electron microscope studies of iron complexes of adrenaline hydrogen tartrate and catecholamine

Iron was found to form coloured stable complexes with both adrenaline hydrogen tartrate and catechol as inhibitors for iron corrosion in aqueous solutions of different pH values [2.0-11.5]. The electrochemically formed complexes on the surface of the iron electrode in different media were separated and studied in comparison with the same complexes prepared by chemical method in the same media. The prepared complexes were studied using micro-, electro-and thermal analyses together with electron ionization mass [EI-MS] and IR spectral methods. Both chemically and electrochemically prepared complexes were found to be of the same structures. The electrochemically formed complex in different media was found to be as a chemisorbed layer on the surface of iron electrode. The aim of the present work is to compare the results of chemical and electrochemical techniques in preparation of stable iron chelates of both adrenaline hydrogen tatrate [AHT] and Catechol [Cat.] as inhibitors for iron corrosion. The morphology of the chemisorbed complex layers on the electrode surface was also tested by electron microscope [EMS] and characterized as an amorphous or crystalline adsorbents

Effect of chemical composition of zinc phosphating solution on phosphate coating properties

Phosphate coatings have a wide field of applications in industry. The applications of coatings are classified according to the film thickness and the type of solution employed. In this study the phosphating process in the zinc-phosphating-nitrate accelerator on steel gave a phosphating layer of suitable morphology which was investigated by different instruments like SEM/EDS and XRD. The crystal size and the thickness of phosphating layer were found to be iron content dependent. Therefore, adjusting of phosphate, zinc and iron concentrations is very important to get a suitable phosphating effective process. The aim of the present work is to control the iron concentration in the phosphating bath in order to improve the quality and adhesive properties of zinc phosphating coating on steel sheets that always used for military purposes in Helwan Engineering Company in Egypt

Investigation of molecula structure - chirality relationship of ephedrine and pseudoephedrine drug using thermal analyses and mass spectrometry techniques combined with MO-calculations

Two diastercoisomers ephedra drugs namely; ephedrine [eph.] and pseudoephedrine [psi-eph.] hydrochloride, have been investigated for their chirality using thermal analysis [TA] measurement [TG/DTA] and electron ionization mass spectrometry [EI-MS] at 70 eV. Monte Carlo conformational search technique was used for exploration of conformational space of ephedrine and psi-eph., using Amber force field molecular mechanics method. MO-calculations were performed using semi-empirical PM3 procedure on the obtained conformational sample for investigation of the different molecular properties. The calculations include bond length, bond order, charge distribution, ionization energy and heat of formation, in neutral and positively charged forms for the two drugs. The effect of diastereoisomerism on thermal analysis decomposition behavior of these drugs was studied. The obtained data confirmed the chirality and declared the structure reactivity relationship of these drugs

Electrochemical behavior of copper electrode in different solutions of adrenalin chydrogentatrate and catechol

Galvanic anodic polarization of copper electrode at different current densities in electrolytes of different pH values containing adrenaline hydrogen tartarte [AHT] and catechol [Cat.] have been studied. The effect of complex formation on the underlying anodic reactions and inhibition effect of these complexes on copper electrode is also studied. The cathodic deposition of copper in the prepared complexes on the surface of the cathode is involved to check their stability at different pH values and the effect of this stability on cathodic behavior of copper electrode

Spectrophotometric determination of levodopa, carbidopa and alpha-methyldopa

The dopamine derivatives participate in the regulation of a wide variety of physiological functions in human body and in medication life. A sensitive spectrophotometric method is developed for the determination of levodopa [LD], carbidopa [CD] and alpha methyldopa [MD]. It proposed on the bases of metal complex formation of these compounds with copper tetramine then coupling with 4-aminoantipyrine. The optimum conditions [pH, time, ratio and sequence of addition] are established. The method permits the determination of LD, CD and MD as a rectlinear relation in calibration curve over a concentration range 19.72 to 69.02, 13.79 to 63.34 and 31.24 to 98.94 micro g ml -1, respectively. The obtained data of SD [0.174 to 0.59], CV [0.68 to 1.16%] and correlation coefficient [0.995 to 0.999] reflect the reliability, reproducibility and accuracy of this procedure. The method is applicable to the assay of LD and MD in pharmaceutical drugs [Levocare and Aldomet respectively], and the results are in a good agreement with those obtained by the official method. The method was simple, rapid, reproducible and accurate to follow of medication of schizophrenic patient

Spectrophotometric assay of levodopa and alpha-methyldopa in pharmaceutical products and in biological samples of schizophrenic patients using copper complex and tri-iodide reagent

Two simple, rapid and sensitive spectrophotometric methods are proposed for the determination of levodopa [LD] I, and alpha-methyldopa [alpha -MD] II. The first method is based on coupling of 4-aminoantipyrine [4-AAP] with LD and a alpha -MD to give new ligands that react with copper-tetramine complex to give intense colored chelates of ratios [1:1:1, LD or alpha -MD: 4-AAP: copper tetramine]. The colored products are quantified spectrophotometrically at 520 and 545 nm for LD and a alpha -MD, respectively. The optimization of the experimental conditions is described. The method has been used for the determination of 19.72-69.02 and 31.24-98.94 micro g ml[-1] of drugs I and II, respectively. The accuracy of the method is indicated by the values of recovery [100 +/- 0.2%] and the precision is supported by the low standard deviation [SD 0.17-0.22] and relative standard deviation [RSD=0.59-1.54%]. The second method is based on the formation of ion-pair iodinated inner sphere or outer sphere colored complexes between the drug and iodine or tri-iodide negative ions at pH 5 and room temperature [25 +/- 3°C]. This method has been used for the determination of LD within the concentration range 39.44-78.88 micro g ml[-1] with SD=022-0.24 and recovery percent=100 +/- 0.3%. The sensitivity of the two methods is indicated by Sandell factor of 0.014- 0.016 g cm[2]. The results of the two methods are compared with those of the official method. The interference from common drug additives, degradation products and excepients was also studied. The proposed methods were applied successfully to the determination of LD and alpha-MD in dosage forms. The second method was also successfully applied for the analysis of LD and carbidopa [CD] synthetic mixture of concentration of these drugs similar to that of Aldomost drug form of LD, and also the determination of these drugs in urine of some schizophrenic patients with good precision and accuracy. The reliability of the methods was established by parallel determinations against the official British pharmacopoeia method

Ammonium adsorption properties on clinoptilolite as soil amendment

The physical, chemical and mineralogical properties of the zeolite were examined by different physicochemical methods of analyses. Chemical analysis of major elements and determination of Si/Al atomic ratio were performed aiming to compare its content with the standard sample. The clinoptilolite samples was subjected to a physico- chemical study for evaluation of its cation exchange capacity [CEC]. The quantitative determination of CEC through molecular sieving properties indicated that it was controlled by particle size, so that the increase in the particle size slightly decreased the CEC values. Two particle sizes [20-50 and 50-75 mum] of K-clinoptilolite were used to study the exchange of K+ by NH4+ on zeolite. It has been shown that the amount of NH4+ uptake on clinoptilolite is higher for the smaller particle size fraction, increasing with increase of NH4+ concentration