lect 9 Flashcards
what are bonding and structure of metal complexes?
what is humic and fulvic acids?
what are humic acid compounds?
classified on the basis of solubility
-1. non-extractable plant residue referred to as humin
-2. humic acid precipitates from the acidified aqueous extract
-3. the soluble portion that remains in the acidified extract is referred to as fulvic acid
-the acid-base, sorptive, and complexing properties of the soluble/insoluble fractions have a strong effect on the properties of water
what is the complexation and chelation affect ligands and metals?
-oxidation-reduction, decarboxylation, hydrolysis and biodegradation of ligands
-solubilization, precipitation, absorption, distribution, transport and effects of metal ions
-biochemical effects of metals including bioavailability, toxicity, uptake by organisms (metal poisoning therapy)
what are the occurrence of chelating agents?
-biocompounds such as hemoglobin
-metabolic products or organisms
-pollutants such as from metal plating wastes
-chelating agents in water may facilitate algal growth by making soluble nutrient iron available
what is the role and applications of metal chelation?
thiomersal in vaccines and autism???
-thiomersal has been used as a preservative in vaccines. It has been purported as a cause for autism in children
-while exposure to mercury may result in damage to brain, kidneys, and developing fetus, the scientific consensus is that thiomersal has no such effects…
what is thiomersal?
a 2011 journal article described the vaccine-autism connection as “perhaps, the most damaging medical hoax of the last 100 years”
solution on slide 11?
slide 11
what are some examples of formation constants?
what is chelation graph?
what is NTA?
bonding and structure of metal complexes
what is the complexation by protonated ligands (shown with NTA)?
what is the graph of the distribution of species as a function of pH for unchelated nitrilotriacetic acid (NTA)
solution on slide 16
slide 16
