Nail Polish sample prep for LCMS and GCMS

Discussions about sample preparation: extraction, cleanup, derivatization, etc.

4 posts Page 1 of 1
Hello,

I am an undergrad chemistry student and I am in a forensic chemistry class that is technically graduate level. I do not have much analytical experience, so I feel like I maybe bit off more than I can chew. I have a project for this class that involves analyzing nail polish via 3 instruments: DART MS, LCMS, and GCMS. I have a DART MS method planned out because it does not require sample prep. However, I am unsure of what to do with the nail polish to prep it for GC and LC analysis, so I am hoping to get ideas for the sample prep portion.

For GC: I am hoping to see if I can detect any toxic chemicals that may be present in the nail polish, specifically DBP, toluene, formaldehyde, and/or TPP. I have found a few research papers that mention using methanol as the solvent for the polish in GC. My concern is that I do not want to overload the column or clog it. How do I know if it will or not? How do I know it will be safe to put the nail polish in the GC with just mixing it in methanol?

For LC: I am hoping to see if I can get peak readings for the possible dyes or pigments in the nail polish. I have been unable to find any related research for this. I have some experience extracting dyes from nylon fibers via organic solvents and extracting by heating the mixture at 100 degrees C for an hour prior to putting the sample in LCMS. If I try the same with the polish, is it safe? Will the polish be too flammable (I think most are based in acetone but some of my samples I do not have ingredient list).

I just don't want to break anything or damage thousands of dollars of equipment and I do not have enough analytical knowledge to plan this myself. My professor is very hands-off and believes in trial and error, but I'm terrified. :shock:

Thanks in advance for any advice,

Crazy undergrad chem student who took a grad class too early
Another bit of advice - posting the same question all over the forum doesn't help.

Peter
Peter Apps
oh lol. I did not realize they were all visible. it seemed like each one was separate. sorry
The student project forum is best for your request. Most of us check all of them regularly - at least I see a lot of the same contributors on nearly all of the subforums.

It sounds like you're just trying to find things in the uncured nail polish. Is that correct? Phthalates are good because they're supposed to be endocrine disruptors. They also give beautiful mass spectra so they're easy to detect at very low concentrations. With GCMS, you don't want to inject a boat-load of polymer into it. It'll mess up your inlet and your syringes. Try to find a solvent that is good for the phthalates (that's the easy part) but a nonsolvent for the polymer. The solvent will dissolve the analyte but leave the polymer behind. If you can centrifuge the sample, you'll likely get a clear supernatant liquid you can inject into your GCMS. If you need to quantitate, I would choose the method of standard addition.

For HPLC, you might go after the formaldehyde. I'm sure you can find a procedure that will show you how to derivatize the formaldehyde with 2,4-dinitrophenylhydrazine. You can then extract it out of the matrix (solvent extraction, evaporate the solvent, reconstitute the residue in an HPLC-friendly solvent) then inject. Reversed phase HPLC is a good way to separate the derivatives of the lower-molecular-weight 2,4-DNPH derivatives (MeOH:H2O or ACN:H2O work well).
4 posts Page 1 of 1

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