| Pages:
1
2
3 |
Bert
Super Administrator
Posts: 2821
Registered: 12-3-2004
Member Is Offline
Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
|
|
Hi everyone-
There is a bit of gold mixed in with the dross here, and it IS in "beginnings".
I don't want to detritus, erase or lock the thread. It HAS gone far afield, with apparent hard feelings by some.
Perhaps some could edit their posts a bit for civility, and everyone could either drop it or address the OP's question? There's nothing I can see
worth getting bent out of shape or use of colorful language here!
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
|
|
|
acetone
Harmless
Posts: 35
Registered: 13-5-2013
Member Is Offline
Mood: No Mood
|
|
I do not care about the fate of this thread anymore. I got what I was looking for. People have replied that
1. Some people have replied that I can consume reagent grade Zinc Sulfate after 3 or more crystallizations
2. Some people have replied that do not eat reagent grade ZnSO4 at any cost due to dangers of heavy metal contamination
The measure of a man is what he does with power.
-Plato
|
|
|
forgottenpassword
Hazard to Others
Posts: 374
Registered: 12-12-2013
Member Is Offline
Mood: No Mood
|
|
If you are satisfied with vague and contradictory answers, why did you bother asking the question at all? If you provide the certificate of analysis
for your reagent grade zinc sulfate it will be possible to answer your question very easily.
|
|
|
acetone
Harmless
Posts: 35
Registered: 13-5-2013
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by forgottenpassword  | | If you are satisfied with vague and contradictory answers, why did you bother asking the question at all? If you provide the certificate of analysis
for your reagent grade zinc sulfate it will be possible to answer your question very easily. |
By asking the question I came to know that one of the impurities in zinc can be cadmium which as you know is a toxic metal and this info is good
enough for me. I will not take the risk of ingesting something which may contain cadmium as one of the impurities.
What is this certificate of analysis which you are asking about? Finally there is no contradiction or vagueness, different people provided their
points of view. It was up to ME to decide what to with the info that they provided.
The measure of a man is what he does with power.
-Plato
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
Off Topic, sort of
| Quote: | | Tobacco smoking is the most important single source of cadmium exposure in the general population. It has been estimated that about 10% of the cadmium
content of a cigarette is inhaled through smoking. The absorption of cadmium from the lungs is much more effective than that from the gut, and as much
as 50% of the cadmium inhaled via cigarette smoke may be absorbed.[62] On average, smokers have 4–5 times higher blood cadmium concentrations and
2–3 times higher kidney cadmium concentrations than non-smokers |
http://en.wikipedia.org/wiki/Cadmium#Safety
Edit--just found this interesting, that's all^^^
[Edited on 6-17-2014 by arkoma]
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
|
|
|
Etaoin Shrdlu
National Hazard
Posts: 724
Registered: 25-12-2013
Location: Wisconsin
Member Is Offline
Mood: Insufferable
|
|
Acetone, if you really have a reagent grade chemical, the supplier should provide a certificate of analysis on request. It will show the purity in a
basic percentage at least, and pretty much always includes heavy metals analysis.
|
|
|
acetone
Harmless
Posts: 35
Registered: 13-5-2013
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Etaoin Shrdlu | | Acetone, if you really have a reagent grade chemical, the supplier should provide a certificate of analysis on request. It will show the purity in a
basic percentage at least, and pretty much always includes heavy metals analysis. |
OK I will try asking him.
The measure of a man is what he does with power.
-Plato
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
So... would recrystalizing ZnSO4 in pure Ethanol a few times (as it seems to have been suggested) make it pharma grade / eliminate heavy metal traces?
|
|
|
Tsjerk
International Hazard
Posts: 3022
Registered: 20-4-2005
Location: Netherlands
Member Is Offline
Mood: Mood
|
|
Maybe, maybe not, without analysis you won't know. Just to summarize this thread.
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
Does anyone on the forum have trace metal analytical capabilities?
I (or anyone who cares to) can carry out a pre-agreed recrystalization process, send the sample to the person who can do the analysis, and results
published here for the general knowledge of whoever is curious to know how efficiently zinc (in the form of sulphate) can be purified from heavy
metals using recursive recrystalization alone.
|
|
|
yobbo II
National Hazard
Posts: 710
Registered: 28-3-2016
Member Is Offline
Mood: No Mood
|
|
God be with the good old days when petrol contained lead
https://www.chemistryworld.com/news/historical-lead-from-pet...
You can get kits for testing for heavy metals etc.
https://www.simplexhealth.co.uk/product/quick-test-kit-for-c...
Are 'food grade' chemicals safe to eat?
Yob
[Edited on 22-7-2022 by yobbo II]
|
|
|
Fulmen
International Hazard
Posts: 1693
Registered: 24-9-2005
Member Is Offline
Mood: Bored
|
|
@Veritas: That's not going to work. All you can prove is that that one particular batch made by you using specific raw materials was good. There is no
magic process that can guarantee a perfect product. Everything depends on proper analysis.
We're not banging rocks together here. We know how to put a man back together.
|
|
|
VeritasC&E
Hazard to Others
Posts: 176
Registered: 29-1-2018
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Fulmen | | @Veritas: That's not going to work. All you can prove is that that one particular batch made by you using specific raw materials was good. There is no
magic process that can guarantee a perfect product. Everything depends on proper analysis. |
I can specifically throw in say 100ppm of the corresponding salt of each known impurity (Cd, Hg, As, Pb, Cu, Ag, Co, Ni, Mn, Fe, etc.) into the
starting material (the rest being 5N Zinc) to see how each is impacted, thus serving as a generally applicable proof of concept (of course HOW
recrystalization is performed has a good impact, but it will prove what recrystalization certainly CAN do, and which impurities it is least efficient
at churning out of the initial material).
|
|
|
| Pages:
1
2
3 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
