Can I use NMP as a solvent for RP-HPLC analysis?

[moonchips]

Greeting,

I would like to know if it is OK to use NMP as a solvent for RP-HPLC analysis with 5uL injection.

Is it going to ruin the C18 stationary phase? I do observe a huge peak at void.

thanks

[moonchips]

and what about DMA?

Thanks

[danko]

I wish I knew what “NMPâ€

[bisnettrj2]

For starters, I have no idea if you can use either solvent in RP-HPLC. My guess is probably "it depends". More info on either solvent...

Google tells me NMP is N-Methylpyrrolidone, and DMA is Dimethylacetamide.

NMP "is the lactam of 4-methylaminobutyric acid and a very weak base. NMP is a chemically stable and powerful polar solvent. These characteristics are highly useful in a variety of chemical reactions where an inert medium is of concern. Despite the stability of NMP, it can also play an active role in certain reactions: hydrolysis, oxidation, condensation, conversion with chlorinating agents, polymerization and o-alkylation, and related reactions."

http://www2.basf.us/diols/bcdiolsnmp.html


DMA is "used as a solvent for polyacrylonitrile, vinyl resins, cellulose derivatives, styrenes and linear polyesters. Also used as a catalyst and solvent in elimination, halogenation, cyclization, alkylation, interesterification, and phthaloylation reactions."

http://www2.dupont.com/Products/en_RU/D ... de_en.html


I assume more info from moonchips may be necessary (for the smart guys on the forum):

Column type? Perhaps manufacturer, packing material, length, I.D., etc?

Other mobile phase constituents?

pH?

Temperature?

Detector?

Analyte type/names?


I found one aplication note for a "N-Methylpyrrolidone (NMP) + 0.1M LiBr mobile phase" in the analysis of 'Poly (Vinylidene Fluoride)' on 'Jordi DVB GBR Mixed Bed Linear' column, 500 x 10mm ID

http://www.gentechscientific.com/an59.htm


I found an abstract more a method using DMA as a constituent of a mobile phase on a C8 column "for the sample preparation and handling for the determination of amino acids, monoamines and metabolites from microdissected brain regions of the rat".

http://www.medscape.com/medline/abstract/9698226


Mostly, though, it seems these solvents are used in SEC/GPC.

[grzesiek]

"I would like to know if it is OK to use NMP as a solvent for RP-HPLC analysis with 5uL injection." - by the things you write I'm guessing you wanna use it as a diluent

The size of the injection does say nothing without size of the column

Taken all into account I personally wouldn't worry about the column

"I do observe a huge peak at void. " - you do inject polar solvent right?

What about dissolving your analytes in these solvents, and then diluting with some other solvent like MeOH/ACN/Water or simmilar to get rid of the huge peak at void?

[bhuvfe]

Moonchips,

Do you want to use it as diluent for your samples or in the mobile phase?

It has quite a high UV cutoff so detection by UV might not be the most practical choice ( http://macro.lsu.edu/HowTo/solvents/UV%20Cutoff.htm).

I wouldn't see any problem in injecting it in any HPLC column or using it as
mobile phase till you can stay under the maximum tolerated column pressure and have a decent detector.


Do you plan to use it for non aqueous RP?
http://macro.lsu.edu/howto/solvents/Pol ... 0index.htm


Regards,
bhuvfe

[moonchips]

Sorry for any confuse.

NMP is N-Methylpyrrolidone, and DMA is Dimethylacetamide.

I would like to use them as sample diluent and inject directly onto HPLC.
Column: YMC C18, 100*4.6*5
Temperature: 25
Mobile A: 0.05% TFA
Mobile B: 0.05% ACN
PH: 2
Detection: 240nm UV
analyte: small API with MW about 500 base molecule
injection size: 5uL


Thanks a lot

[bisnettrj2]

I would agree with grzesiek then, such a small amount of solvent shouldn't be an issue as an injection solvent. However, I do wonder why you aren't just dissolving your standards/samples in your mobile phase?

[Chromatographer2010]

DMAC and NMP help with solubilizing samples in a smiliar fashion to DMSO without the added viscosity.

With silica based C-18 columns like yours they have not caused me any problems in the past and I have seen their use in the literature.

[bisnettrj2]

Ah, I see. I'm not a pharma guy, so I learned something today. Yippee!