Hi, two questions:

1. for the cell experiment, it is better to use lower concentration of DMSO , less than the maximum tolerated dose of your cells, otherwise it will be difficult for you to tell if the results are accurate or not, because there maybe exist the synergism of your compounds and DMSO.

2. It would be better if you can analyse your sample with lower concentration of DMSO, and filter the sample with microporous membrane or centrifuge at high speed, for protecting the GC/HPLC-MS column. MeOH would be ok for your sample dilution, the points mainly is the nature and concetration of your sample.

Good luck for you:)

You can analyze DMSO matrices on GC/MS, but it is not ideal. It is typcially used as a solvent in HS/GC/MS analysis of volatiles, but has problems with carryover and system contamination. If you are performing a direct injection method, I'd have conecrns that this compound would cause peak distortion, and would also elute later in the analysis potentially obscuring peaks of interest. Diluting is an option, but I wouldn't recomend methanol for this purpose since it is too polar. If possible, a beter GC solvent like dichloromethane of ethyl acetate would be advisable.

Thank you Cai and Steven.

I will try diluting with ethyl acetate since I used it as the extraction solvent and keep my sample concentration < 1mg/ml.

Hi ALison, u faced any problems with GC, when you had diluted with dichloromethane of ethyl acetate.

Hi CV Chandra,

My extract dissolved well in ethyl acetate but I got really small peaks, which made quantification almost impossible. I increased the concentration but that didn‘t help. Not really sure why but I think the compounds are not volatile. Should have gone for lcms or derivatization.

Hi Alison S Y Fong,

Once your extract is soluble in ethyl acetate half of the problem is solved since ethylacetate is very volatile and better solvent for GCMS than DMSO. for you to increase the prominence of the peak you can raise the ms detector voltage a bit (about 0.2 KV) but be careful not to saturate the detector by raising it to much. For quantification I recommend you use SIM mode, here you can raise the detector voltage to further extent for proper detection without saturating the detector since ions monitored are fewer than in scan Mode. Wish you best of luck.