Chromatography Forum

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.

Thanks in advance for any advice,

Crazy undergrad chem student who took a grad class too early

Hi vanene1313,

What type of MS detectors are you using for each system? The starting concentration is really dependent on how sensitive the detectors are.

Do you have some standards of the analytes you expect to find?

Hello Rogue,

Unfortunately, I do not have standards available (none of the toxins or possible nail polish pigments), which is why I do not understand why my professor is pushing the GCMS and LCMS instruments. My original idea was to make a DART MS fingerprint library for as many nail polish samples I could process...and see if profiling the nail polish was significant in that their fingerprints would vary enough to distinguish between them. I am supplying my own nail polish so that would be free. It is an independent project that we would have to fund ourselves (and I'm a broke college student so I won't be able to spend much). Maybe he just wants me to become comfortable with the instruments? There is some merit in reporting failure or inconclusive results I guess. Or perhaps I can just report anything that the spectra show and pray it matches something on the listed ingredients?

For the LCMS, we are using a Perkin Elmer AxIon 2 TOF MS. The MS on the GC is also perkin elmer Clarus SQ 8C (I confess I do not know which MS type this one is. maybe quadrupole???). Thanks for the help!

Hi Vanene,

So a TOF and a SQ (single quad). The TOF is definitely a delicate machine. I would start with GC. What solvent is it in? (acetone perhaps), can you keep the rest on the components dissolved in a lower boiling point solvent? (MeOH), thendilute perhaps 2 ul/ mL and sonicate. Filter 0.45um PTFE and shoot 1ul. Spiltless first minute then 50:1 split. 250oC injector

Don't forget to test careful for your solvent delay time using a blank. Use the lowest current avail and be prepared to turn off the filament if your solvent delay time is too soon.

Next increase the current and multiplier, and shoot a blank and the sample acquiring 5 amu above the solvent mass up to 800m/z?

If you don't see much, ask if you should try a more concentrated sample.

A good lit search for GC MS analysis of paints would be a good place to start.

Have fun!