Nermin Salah

4 Questions 4 Answers 0 Followers

Questions related from Nermin Salah

How can I increase the ionization of organic molecules so I can analyze them using ESI MS/MS, I tried +/- ionization mode?

I have some organic molecules (carbamate derivatives) they show UV absorption yet looking in the mass scan , I can not see any ionization , I have tried positive and negative mode of ionization...

19 October 2016 1,078 3 View

What are best chromotographic conditions for carbamate derivative analysis via LC/MS?

I have been trying to determine some carbamtae derivatives using LC/MS, I am using ESI/positive ion mode ; gradient elution: water+0.1 % TFA then acetonitrile+ 0.1 % TFA but no ionization is...

10 February 2016 3,694 4 View

Any advice about the stability of ester and carbamate containing compounds?

How can I prevent compounds with ester and carbamate group on a phenyl ring from hydrolysis even though I keep them in freezer with no solvent still I face excessive hydrolysis that is obvious in...

25 November 2015 454 3 View

N-BromoSuccinimide (NBS) reaction

I am using N-BromoSuccinimide (NBS) to brominate an allylic carbon, I am using CCl4, benzoyl peroxide and light. The starting material disappeared yet no brominated product was obtained, LCMS...

01 January 1970 878 3 View