Empakt
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Another Mercury Ion question
Basically I am working on a project that involves detecting mercury ions within biological tissues. After dissolving the tissues, I intend to analyze
the supernatant with a dithizone solution because it has been known to accurately detect the presence of mercury. One roadblock I am currently having
is that there is no consistency in the way it reacts to the mercury solution.
Do any of you know what color solute the dithizone should form upon interaction with the mercury ion? I researching and there were apparently no
sources that stated what results after mercury is detected in a dithizone solution, only complex compounds. But there has to be a color since this is
used to detect mercury ions with a visible spectrometer. My tirals have ended up with no color being produced or the smaller the ppm concentration of
mercury ions in a standard, the greater the intensity(which cannot be right).
Also the article that I am basing my project on directed that the diphenylthiocarbazone should be dissolved in isoamylalcohol. My main problem with
this is that there is a separation of layers when I add in the dithizone solution to the mercury solutions dissolved in water. How do you all suggest
I circumvent this? Add the mercury solution to the dithizone solution instead of vice versa to mix the mercury ions with the solution?
Finally do any of you know of a more efficient way to detect mercury ions with a visible spectrometer?
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Empakt
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Also when dissolved in a solvent, should the dye solution be clear or colored?
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unionised
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IIRC Dithizone goes red with mercury. Unfortunately, zinc, lead and some other metals also make it go red so you won't know what metals you have in
your sample.
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Empakt
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When I made the dye, it had a reddish hue. I thought it was fully dissolved. But observing it again, the dye solution was clear. Could the dye have
degraded or is the solution supposed to end up being clear and turn into a color upon ion detection?
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unionised
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Here's a picture (albeit, not very clear and with lead rather than mercury)
http://genchem.chem.wisc.edu/demonstrations/Analytical/pages...
One potential problem is that traces of metals in the solvent can be enough that the stuff goes red anyway.
You might be able to get round this by washing a solution of dithizone in an organic solvent with fairly strong acid (say about 1M) to strip metals
from it.
It's also quite possible that the stuff is degraded.
I still think that the big problem will be the lack of selectivity. If your solution turns red you won't know if it's toxic levels of mercury or
normal levels of other metals (Cu, Fe, Zn)
[Edited on 22-1-2006 by unionised]
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