De-masking of magnesium—acetylacetonate complex for direct ethylenediaminetetraacetic acid titration of calcium and magnesium in the same solution and at the same pH

Abstract

A simple complexometric method, with ethylenediaminetetraacetic acid as titrant, was developed for the determination of calcium and magnesium in a single aliquot of solution at pH =lo. The method involves determination of calcium at pH =lo, with use of a mixed indicator, after masking magnesium with acetylacetone at room temperature, followed by de-masking of magnesium at 90°C and direct titration of magnesium at the same pH. The method was standardized against synthetic solutions and applied t o various calcareous materials, and the results were compared with those obtained by a standard method.

Electroweak radiative corrections to polarized Mo/ller scattering asymmetries

“…If high mass scale "new physics" enters through gauge boson propagators, it is conveniently studied using the Peskin-Takeuchi S, T , and U parameters [18]. If the scale of the "new physics" is O(m Z ), rather than ≫ m Z , that formalism should be extended to S, T , U, V , W , X [19,20]. The additional quantities parametrize changes from Q 2 ≈ 0 to m 2 Z due to "new physics" loops.…”

“…A measurement of A LR to ±7.8% or ∆ sin 2 θ W to ±0.0011 then constrains X at the ±0.14 level. That is to be compared with global fits to all existing data [20] which currently give X = 0.38 ± 0.59. So, an A LR measurement could improve the constraint by a factor of 4 or so.…”

Inorganic metal salts as additives in the design of cellulose/arabinogalactan hydrogels for prolonged delivery of simvastatin in simulated bio‐fluids

“…The zinc content in the hydrogel matrix as well as in dissolution media was determined by complexometric titration. [57][58][59] To determine the zinc content in the hydrogel matrix, accurately weighed, 10 mg hydrogel particles (CMH4) were crushed in a mortar and pestle and transferred into 100 mL phosphate buffer solution (pH 7.0) for overnight digestion. To 10 mL test solution, acetyl acetone (0.75% w/v) was added as masking agent for Al 3+ ions at room temperature (25 ± 5 C).…”

Chemical species

“…Calibration curves for the phosphorus oxyanions were linear in the range of 3 to 30 mg P/L. Kundu and Roy (1993) developed a simple complexometric method for the determination of calcium and magnesium in the same sample at pH 10.…”