I am working on a nitrogen hrterocyclic, in acidic solution it gets dissociates, my mobile phase is not capable to neutralise the acid (weak buffer capacitty). This gives me a problem if peak tailing and problem in peak purity. My question is, to neurealise the acid(hydrochloric) can I use sodium hydroxide (as excess of sodium hydroxide can dissolve silica).

I guess you are testing your method for degradants by forced degradation.

When I perform this test, I always neutralize my solution before injection. (not for peroxide)

example: When I add 2 ml HCl 0.1 N to mmy standard, I wait ±30 min, and then I add 2 ml NaOH 0.1N.

No, i am doing dissolution test in that my media is 0.1M hydrochloric acid for initial few hours followed by Buffer pH 7.5. In buffer i am not getting any problem, my peak deforms only in acid stage.

Ok, now I understand.

What kind of HPLC do you have? With the Waters Alliance modules its possible to mix multiple vials before injection. Maybe you can add some NaOH to your samples before injection?

I am not talking about online addition of sodium hydroxide, I am talking about addition of sodium hydroxide in last dilution which i am injecting on HPLC(So that my peak shape will improve and peak purity will pass).

please comment

There are other solutions to your problem also. You could use a packing that is not sensitive to alkaline hydrolysis. Now you can use the sodium hydroxide freely. Alternatively (or even concommittantly), you could use ammonia, which is a milder base. if you overshoot with that, there is less concern.

hi

you CAN use NaOH to neutralise the media...i do it with one of my disso samples too. But during method dev stage check the pH of the final soln. so that you may adjust the quantity of NaOH to be added. If you can dilute the sample without losing peak response, u may try to pipette 5ml of your sample soln..(0.1M HCl)..add 5ml 0.1M NaOH...and dilute with the 7.5pH buffer (what u use in the later stage of the dissolution)to,say,25ml.