A flow injection procedure for the sequential spectrophotometric determination of iron(II) and iron(III) in pharmaceutical products is described. The method is based on the catalytic effect of iron(II) on the oxidation of iodide by bromate at pH = 4.0. The reaction was monitored spectrophotometrically by measuring the absorbance of produced triiodide ion at 352 nm. The activating effect for the...

...............................................................................................3 Introduction............................................................................................3 Arsenic Maximum Contaminant Level.............................................................3 Arsenic Speciation...................................................................................

Arsenate [As(V)]-respiring bacteria affect the speciation and mobilization of arsenic in the environment. This can lead to arsenic contamination of drinking water supplies and deleterious consequences for human health. Using molecular genetics, we show that the functional gene for As(V) respiration, arrA, is highly conserved; that it is required for As(V) reduction to arsenite when arsenic is s...

Chemical speciation of soil cadmium (Cd) dictates its mobility and potential toxicity in the environment. Our objective was to compare temporal changes in speciation of Cd(II) reacted with samples from six Brazilian soils having varying Cd(II) sorption capacities. Cadmium L-edge X-ray absorption near edge structure (XANES) analysis showed there were short-term changes in speciation after reacti...

The solubility and behavior of iron (Fe) in natural waters is tightly linked to Fe speciation, speciation likely influences how distributes between the water column sediments. In this study, function a lake as an sink, with focus on role was assessed for Lake Bolmen southern Sweden. We found that large fraction flowing efficiently lost by sedimentation basin. inflowing mix organically complexed...

The bulk of the cement industry's environmental burden is from calcareous source. Calcium mostly available naturally as limestone (CaCO3), where almost half mass eventually released CO2 during clinker manufacture. Iron (Fe) fourth most common element in Earth's crust surpassed only by oxygen, silicon, and aluminium; therefore, potential raw materials for alternative cements can contain signific...

introduction: boron is one of the eight essential micronutrients required for plant growth and development. the optimal concentration range (between deficiency and phytotoxicity) for boron is narrower than for other plant essential nutrients. generally, irrigating water containing concentrations of b greater than 1 mg l-1 would be detrimental for most plants. although, there are a large number ...