sample in pH=7.4 buffer with salts

Discussions about sample preparation: extraction, cleanup, derivatization, etc.

3 posts Page 1 of 1
Hello,

I've been working on method development for a molecule and the sample matrix is pH=7.4 buffer with salts. The QC samples have been behaving very strange. All the QCL samples recovery is around 80%. But the QCH samples recovery is sometimes 93%, sometimes around 65%. I've tested for several times and I just cannot control it.
I tested the stock solution from which I prep the QC samples and it's right on spot. I don't know what is happening I've been stuck here for a long time.

I just started doing method development and I really appreciate it if any one can give me some help.
More detailed information about your prep process would be very helpful. And I assume by QCL and QCH you refer to two concentration levels?
I'm really sorry that I forgot to reply (3 months... i'm so sorry). Just let you know I figured out the problem shortly after I posted the question. The drug has a propensity to attach to the tube and that causes the problem.
3 posts Page 1 of 1

Who is online

In total there are 3 users online :: 0 registered, 0 hidden and 3 guests (based on users active over the past 5 minutes)
Most users ever online was 599 on Tue Sep 18, 2018 9:27 am

Users browsing this forum: No registered users and 3 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry