Dimethylamine hydrochloride tests

[vishnu]

Tests either in hplc or in gc needed. is there any method for testing dma hcl (N-methylmethamine) by gc or hplc???


please help.

[Markus Laeubli, Metrohm]

I would recommend cation exchange chromatograph (IC) with conductivity detection.

See a typical column out of the Metrohm range: Metrosep C 4 - 140/4.0
Eluent conditions: 1.7 mmol/L nitric acid, 0.15 mmol/L dipicolinic acid, 3% acetonitrile (0.9 mL/min).

[pharmaguy]

Fastest way is probably GC - I seem to recall some even sell "amine" columns.

[vishnu]

Thanks for all for the reply.
I think there is a misunderstanding in my words.

I will clarify.
I am asking about DIMETHYLAMINE HYDROCHLORIDE
All the suggestions above are for DMA.

[tom jupille]

I am asking about DIMETHYLAMINE HYDROCHLORIDE
All the suggestions above are for DMA.

In aqueous solution, they are the same thing: dimethylammonium ion.

[vishnu]

Thanks for the clarification.

Is there any method using ODS column (C-18) or a cationic SCX column???
Bcoz i have these both columns in hand. Can i test using these columns???

If it is there, please explain me the method.

[Markus Laeubli, Metrohm]

The scx column (cation exchange) might work.
Us an acidic eluent with some organic modifier with a conductivity detector.
The dimethylammonium cation is retained on the cation exchanger material and will be eluted mainly by the H+ of the eluent acid. The organic modifier speeds up the separation and improves the peakshape.

[DSP007]

Hello Vishnu.
Use GC wich Fid ; packing column (5% Carbowax+ 1% KOH * on S1), head space (90 C) wich water solution or extract on CHCL3 + one drop of NH3 solution.
inj - 100c det -150C , column 60->120 5 C/min.

You detremine [url]dimethylamine as base[/url] and calculate by hydrochloride.

Ion chromatography (HPLC) admixting iones in drug substancies in a salt forms - is a big problem...

[vishnu]

Is UV visible detector effective for that in HPLC???
At what nm i can use for DMA???

[Vlad Orlovsky]

you cannot use UV for this compound, despite the fact that some people think. Your choices for this are LC/MS, ELSD, RI, conductivity and nitrogen detector. if you want to see both ions 9amine and chloride) you need trimodal column like Obelisc N or Obelisc R. If you are looking only at amine you can use Primsep mixed-mode column, similar to this:
http://www.sielc.com/Compound-Ethylamine.html

you can use your SCX column in the same fashion with ELSD, RI or conductivity

[DSP007]

Dimethylamine do'n have chromoforic groups (double bonds).
You can (should) use a admixting of chromofors (benzene , nafthalene and any dues) in liquide phase and register negative peaks in UV-DAD , but this LC- method is'n effective, selective and robatic.

I say. Dear Vishnu "do not torture yourself and chemin de fer " - use a valid GC method by packing column...

[5.56x45mm]

I would recommend cation exchange chromatograph (IC) with conductivity detection.

See a typical column out of the Metrohm range: Metrosep C 4 - 140/4.0
Eluent conditions: 1.7 mmol/L nitric acid, 0.15 mmol/L dipicolinic acid, 3% acetonitrile (0.9 mL/min).

your Ca and Mg peaks are miss identified. They should be reversed, with Ca eluting before Mg.


http://www.metrohmusa.com/Products/Ion- ... Cbr+%2F%3E

[HPLCaddict]

Tests either in hplc or in gc needed. is there any method for testing dma hcl (N-methylmethamine) by gc or hplc???
please help.

I think the most important question hasn't been asked yet . WHAT kind of test do you exactly need?
Verifying identity? Assay? Purity? Anything else?
Nevertheless I'd say my choice would be GC...

[HPLCaddict]

Oops, just realized that this thread is more than a year old ...