RESUMO
Square-wave adsorptive stripping voltammetric method was selected for the investigation of the adsorbed Indapamide[INDP] drug in solutions of varying pH. A method has been developed for the ultra trace determination of INDP inpresence Cu[II], due to the strong adsorption of the Cu[II]- INDP complex at the surface of the HMDE andsubsequent reduction of the surface - bound complex. The observed data has been subjected to statistical analysis,which revealed high reliability and precision. A detection and quantitation limits of 2.9x10[-11]and 8.8x10[-11]mol/L[-1]respectively, were achieved in presence of 5.0x10[-7]mol/L[-1]Cu[II]. The proposed procedure is much simple, fast,more sensitive, reproducible and the calibration graph is linear over range 2.0x10[-12]-2.0x10[-7]mol/L[-1].Moreover, this method was successfully applied to the direct determination of INDP in pharmaceuticals and spikedhuman urine. No prior extraction step is needed in case of urine. The effect of some interferences [Mg[+2], glycine, Fe[+3],uric acid, starch, glucose and Na[2]CO[3]] was considered
RESUMO
Mercury [II] ion-selective PVC membrane sensor based on dimethylsulphoxide [DMSO] as a novel oxygen and sulfur containing sensing material was successfully developed. This reagent has the advantage of low cost and simple chemical material. Dioctylphthalate [DOP] solvent could be selected from different solvents used. DOP was found to play an important role in directing selectivity. A sodium tetraphenylborate [NaTPB] as a lipophilic salt and KCI solution of 10[-1] M as an inner solution also have been chosen. The sensor exhibited a good linear response of 30 +/- 0.2 mV per decade within the concentration range 10[-8] - 10[-2] and detection limit 0.9 x 10[-8] mol 1[-1] Hg [II]. Also, it showed good selectivity and fast response for mercury [II] ion with relation to some alkali, alkaline earth, transition and heavy metal ions. DMSO-based sensor was suitable for aqueous solutions of pH range 1.5 to 4.0. Moreover, it can be used for three months without any considerable divergence in potential. The formation constant of ionophore complex with Hg [II] ion was calculated by using segmented sandwich membrane method. The proposed sensor was applied as an indicator electrode for potentiometric titration of Hg [II] ion with EDTA solution, as well as with I[-], OH[-] and IO3[-] ions. In addition, the solubility products for the previous ions were determined
Assuntos
Dimetil Sulfóxido , EletrodosRESUMO
Purpose To assess the changes in tear composition in rabbits following exposure to Sr90 beta - radiation. Methods The damage induced by beta - radiation from Sr90 applicator, at doses of 20 Gy, 40 Gy and 60 Gy in weekly sitting of 10 Gy to treated left eye and the right untreated one of 25 there-month-old New Zealand white rabbits was assessed. An additional ten rabbits were used as a control. Tears collected after 24 hours were measured for protein content and lysozyme concentration. The lysozyme molecular structure was studied through the use of column chromatography; cellogel paper electrophoresis and radial diffusion technique was utilized for the demonstrated doses. The delayed effects of beta-radiation on tear lysozyme after one and three months' post exposure was also studied. All samples were analyzed six times and the mean result obtained. Results The radiation damage process increased by increasing the exposure doses and this phenomenon still propagated after the study delay periods which reported no remarks for repair. A significant decrease in the lysozyme concentration for the treated and untreated eyes was observed after the dose of 60 Gy [-61.46%] for the treated eye and [-70.64%] for the untreated one. Conclusions Although irradiation has proved to be a valuable tool in controlling eye disease, with excellent survival rates, nevertheless, side effects of radiation form serious limitations for the applicabilities of this technique