Chromatography Forum

HI,

I am analyzing hydrazine and its methyl and ethyl derivatives (i.e. Monomethyl Hydrazine and ethyl hydrazine)

I got easy derivatization of these by benzaldehyde and form corresponding benzalazines. But in case of hydrazine hydrate the derivative was not stable. I got two or three different peaks accept benzalazine peak.
On the other hand when I did derivatization of monomethyl and ethyl hydrazine with benzaldehyde I got a single peak and it was repeatable with run to run.
When I did derivatization of hydrazine hydrate with addition of sodium borohydrate I got a single peak. Some of literatures says that hydrazine hydrate can easily derivatized by only benzaldehyde
I want to know that either there is any relation of pH for derivatization of hydrazine hydrate with benzaldehyde. Because I got one peak only in the case where my solution's pH was basic.
Please clarify and give suggestion regarding the pH concept in hydrazine hydrate derivatization.

Regards

Praveen[/list]

I think there are better places to ask or look for the answer - some forums on organic chemistry reactions or books on the subject, Vogel maybe?

I've done hydrazine hydrate analysis by titration, that method was from Vogel.

Hi praveenpaliwal,

There is one newly published paper by Min Liu and co-workers shows that hydrazine and its derivatives can be well separated and detected by using Hydrohphilic Interaction Liquid Chromatography (HILIC) and chemiluminescent nitrogen detection (CLND).

Detail information can be found in:

Journal of Chromatography A
Volume 1216, Issue 12, 20 March 2009, Pages 2362-2370
doi:10.1016/j.chroma.2009.01.012

Here is presentation on "Fast and Sensitive Method for Residual Hydrazine Analysis in Pharmaceutical Samples" by BristolMyersSquibb presented at Eastern Analytical Symposium. It is describing several approaches including mixed-mode cation-exchange with Primesep column:
http://www.sielc.com/pdf/EAS_HydrazineAnalysis.pdf

Contact me if you have questions.