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Are DMF and CS2 miscible? I ask this because I am trying to use OSHA Organic Method 91 for the first time. The method calls for a 50/50 (v/v) solution and they appear to be immiscible. I need to pipette 3 mls of this mixture but there are definitely two layers, quite soon after shaking.  Should I just shake, pipette fast, and hope for the best? I borrowed old chems from another lab for this exp. Could they be bad or are they really immiscible? It is used to desorb methanol from Anasorb 747.

I have a theory that if they are intentionally immiscible, it is because the vapor pressure of the CS2 carbon disulfide is so high, that it would otherwise be lost to evaporation.

Other observations: CS2 is not hot to the FID? I could not get a peak with a wet needle or .05 uL injection. No problem with the DMF peak when checking for contaminants/breakdown of chems and to establish retention times on our GC column.

I am a new member, so if this is not the proper forum, please forgive me and direct me appropriately. I searched first on CS2, DMF, OSHA Method 91 and DMF/CS2 miscibility before posting. Any help would be appreciated. If these forums are just for college homework problems, please let me know.
Thank you.