a column of alumina modified with sodium dodecyl sulfate (sds) and dimethylglyoxime (dmg) was prepared for the preconcentration of trace nickel from water samples for flame atomic absorption spectrometry (faas) determinations. under optimized conditions (ph=7.0; flow rate: 20 mlmin-1) nickel was retained on the column. the nickel collected on the column was eluted with 5 ml of 1 m nitric acid. ...

a simple, sensitive and accurate method for spectrophotometric determination of dalacinphosphatehas been established. the method is based on the reduction of atomic absorptioncalcium ion by phosphate. because, there is a phosphate mole in every dalacin mole structureand with measurement of phosphate, dalacin is beyond measurement too. therefore, the reactionbetween acidic hydrolysis products of...

cobalt is widely used in different industrial processes for production of various synthetic materials. for assessment of human exposure to toxic metal of co (ii), environmental and biological monitoring are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to instrumental analysis. the aim of this study was to achieve optimum f...

conclusions cu, zn and cr play a specific role in the pathophysiology of diabetic nephropathy. meanwhile in these patients, low serum levels of cu, zn and cr were not associated with factors such as drinking water. possible causes should be sought in other factors like urine, intervention factors in absorption and utilization and individual conditions. results mean ± sd levels of zn, cu and cr ...

objective: the aim of this study was to find out the prevalence of hypozincemia in patients suffering from tinnitus and to investigate the effect of zinc therapy upon the severity of tinnitus. material and methods: we studied 66 who suffered from tinnitus, which were randomized to two groups according to the zinc level including < 50μg/dl and > 50μg /dl groups. the zinc level was measured in no...

in the present study, the concentrations of three heavy metals including lead (pb), zinc (zn) and arsenic (as) in 72 different honey samples collected from north-western regions of iran were investigated using atomic absorption spectroscopy method. all metals were detected in 88.88% of the honey samples. the range of metals contamination in honey samples was 0.01 to 11.09 ppm. zn was the most a...

copper (cu) is an essential element required by all living organisms, since at least 30 enzymes are known to use cu as a cofactor. cu is also toxic in excess and liver and gills are known to be target organs for it. in the present study, 240 siberian sturgeon juvenile (with initial weight 29.2 ± 3.1 g and initial length 21.8 ± 1.4 cm) were randomly distributed in 12 fiberglass tanks at 4 differ...

We show that in experimental atomic force microscopy studies of the lifetime distribution of mechanically stressed folded proteins the effects of externally applied fluctuations cannot be distinguished from those of internally present fluctuations. In certain circumstances this leads to artificially nonexponential lifetime distributions, which can be misinterpreted as a signature of protein com...