[kinat]

Hi people,

Recently my old college purchased a brand new ICP-AES. As a former student I was asked to suggest a few experiments in a toxicological and forensic context. The students don't have a lot of chemistry knowledge and ofcourse dangerous substances cannot be used, limiting my options considerably. Does perhaps anybody with more experience with ICP analyses have a suggestion?

For example I was considering analysing heavy metals in plastics or paint. They have been used as pigments but their use is being phased out so it might be hard to find a suitable sample.

Any help would be welcome,
Kind regards

[marquis]

While the lead is theoretically being phased out of plastics, it is still commonly found.  See the work done by Dr. Jeff Weidenhammer at Ashland University.  A Google search should find it.

[ToxLabRat]

I have over 7 years experience with ICP-MS, ICP-OES, GFAA and FAA.  I have worked with several universities in designing some real world experiments for undergrad students to carry out in the field of elemental analysis.  I would suggest environmental toxicology, as these sample types are less dangerous than medical toxicology (Blood Borne Pathogens Issue).

I would say use the EPA Method for analysis of metals via ICP-OES in water, soil and sludge samples.  I have several step by step SOPs for all of this, including sample prep, how to set up methods on the instrument and how to do the field sampling.  The only real hazards would be the acids you need (HCL and HNO3) but these are both within OSHA regs for college level work, and do not pose much risk as long as the proper PPE is worn.

I am actually right in the middle of a project to get a Perkin Elmer Elan 9000 over at my undergrad school, so I am full throttle in this, so you have caught me at a good time if you want some really in depth info.  One of the main projects that many undergrad schools do, is to take the students out into the field and collect water run off samples near landfills, and then test them for the EPA regulated elements to see how the concentrations look, and see whether or not anything toxic is leaching out of the waste in the landfills and out into the environment.  You can then take all of the data and plug it into a stats analyzer like the program Minitab, or even Excel and see how the different collection points compare to each other.  Then the students can write up reports outlining the process, the analysis as well as draw conclusions based on the data.  It is a good experiment for undergrad students as it gives them some real world exposure into environmental toxicology, analytical chemistry and even regulatory compliance.

If you want some of the SOPs that I have or any other info that is specific, then email me at toxlabrat@hotmail.com

[kinat]

First of all thanks for your replies. The work of Dr. Weidenhammer is very interesting indeed. His references lead me to some very useful info.

The EPA method for analysis of metals in water looks very promising. The equipment to be used at our school is a Varian 710-ES (ICP-OES). I'm also very much interested in those step by step SOPs so I'll email you for them. I think medical toxicology is out of the question indeed. Not only because of inherent danger but also difficulties in obtaining suitable samples.

Any suggestions for an experiment in forensic context would be still be appreciated. Thanks and enjoy your weekend! 

[renge ishyo]

It is also very useful for analyzing the metal content in foods. I did an experiment where I digested hamburger meat with HCl and analyzed a diluted extract to check for calcium, iron levels, etc. Worked like a charm. You can use digest protocols for AA experiments and just modify the last few steps to take into account internal standardization and whatnot needed for the ICPMS. The measurements can be taken in a quick painless manner. Real forensics experiments would be harder to get away with...our school was forbidden to do experiments with human blood, cells, or anything else. Apparently you need a special license to work with human samples (or at least that is what i was told when I asked; I do not know if it was true or not).

[kinat]

Hmm, though interesting I don't really see how the metal content in food is related to toxicology. Unless you're testing for heavy metals but I hope these are below detectable levels anyway.

One idea I had for a forensics experiment is to analyze glass samples for differences in composition. But it seems you'll need either Laser Ablation for direct solid sampling or use HF to dissolve the sample. We don't own a LA device and HF is way too dangerous to use for the students. Perhaps anybody knows any alternatives?

[renge ishyo]

I guess the only relation would be performing an analysis on living (or previously living) tissue. There were a couple of students who tested for mercury levels in fish, but you are right in that you are looking at the parts per trillion level there. The ICPMS can detect at that level as far as I can tell, but the students would need to be very skilled in sample preparation to get a good reading. There were some that were looking for heavy metals in water too, but that was apparently at the parts per trillion level as well 

[marquis]

One big issue a few years ago was aluminum in food or medical devices.  Aluminum in IV components could dissolve and transfer directly to the blood stream.  That lead to a bunch of tests for aluminum in clay, silica, rubber, plastics,etc. 

Again, there should be plenty of internet resources.