Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: muscleriot on January 27, 2015, 07:01:35 AM
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Hi - I use supplements for exercise - Creatine Monohydrate and ZMA (Zinc/Magnesium) powder. I believe that the EU did a study of supplements and found 20% of them had heavy metal contamination. (http://www.sciencedirect.com/science/article/pii/S0308814610016377 & http://www.consumerreports.org/cro/magazine-archive/2010/july/food/protein-drinks/what-our-tests-found/index.htm)
I was just wondering if anyone could suggest any easy ways to identify in a sample of powder supplement at home with basic chemistry equipment if there is any way of testing for such elemental impurities with readily available chemicals? (by titration, precipitation, electrolyisis etc...).
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Not likely. If there's enough to be visualized by a simple precipitation, then you'd be having serious quality control problems. Analytical titration is a possibility, but that requires care and training. If you'd like to try to understand just how difficult it is, by all means feel free to browse the pharmacopeia for the procedure. The EU and USP are similar in this regard, as I understand: http://www.pharmacopeia.cn/v29240/usp29nf24s0_c231.html Usually, you have to pay for this information, but our Canadian friends have politely decided to host outdated USP procedures for our perusal. And that comes in handy from time to time. Although most people are moving to ICP, which is way beyond a home user.
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If you're willing to pay approximately $75 USD, you could send to a commercial analytical lab for ICP-MS testing and get an elemental analysis. This fairly complete and includes analysis of Na, Li, Be, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Bi, Th, U, Au, Br, I, Os Pd, Ra & Ru. That is 63 elements analyzed in many cased down to the ppb level, and the only major elements missing are F, Cl and the noble gases.
If it is a matter of concern for your health if you are consuming these supplements daily then it's worth the $75 and trying to set up any DIY testing would likely cost far more, and not be anywhere as complete and reliable in the results.
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I am based in the UK. Thanks to your post will be looking for a lab that can do the above.
However came across this: DIY spectrometer of http://publiclab.org/wiki/spectrometer-construction.
Seems interesting to me as I believe it could give a quick way of identifying if there have been any changes to the sample substance once I pay for a test. What do you guys think?
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I think that's a poorly informed idea. A diy spectrometer could be anything from a useless toy to a ridiculously complicated and expensive ... well, toy, pretty much. Query: what wavelengths do you suspect heavy metals absorb at that your supplements don't? Can you back up your decision to go this route with anything other than "gee-wiz that looks cool?"
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just if you decide to let a lab figure it out, please send them a whole package and not only a sample you took yourself.
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I am based in the UK. Thanks to your post will be looking for a lab that can do the above.
However came across this: DIY spectrometer of http://publiclab.org/wiki/spectrometer-construction.
Seems interesting to me as I believe it could give a quick way of identifying if there have been any changes to the sample substance once I pay for a test. What do you guys think?
Even if you could find a way to atomize/ionize your sample, which typically requires temperatures in excess of 5000 K, you'll never get the resolution you need to separate the atomic spectral lines using something like this. Think of it this way - if it was this easy, people wouldn't be spending $150,000 for a professional ICP-MS.
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There is an old method that might work. The outline is in USP <231> heavy metals.
Basically, you ash the sample. Then you react it in an acidic matric with hydrogen sulfide.
Heavy metal sulfides produce a dark residue that can be compared easily to a standard
with nessler cylinders.
Hydrogen sulfide is difficult to purchase, but it is not hard to generate. Please note that this
test should be done under a hood.
There can be interferences with this method. The zinc may produce a precipitate. Usually, in
a situation like this, we would filter out the precipitate before addition of the H2S and then
proceed with the test.
The test is relatively cheap, but does have interferences.
Good luck
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Do like marquis: said, or just follow my link to the procedure. ;D