Page 1 of 1

Optimizing applied LC-MS method

Posted: Mon Dec 24, 2018 3:17 pm
by phil1150
Hi,

I have analyzed an alga sample and an oil sample containing the alga in UV-LC-MS using APCI in positive and negative polarity mode. Scan type is full scan.

I am running a gradient method using water (B) and methanol (D).
Time A% B% C% D% μL/min
0 0.00 0.0 99.0 0.0 1.0 500
1 40.00 0.0 1.0 0.0 99.0 500
2 55.00 0.0 1.0 0.0 99.0 500
3 57.00 0.0 99.0 0.0 1.0 500
4 60.00 0.0 99.0 0.0 1.0 500
5 100 0.0 0.0 0.0 500

The UV-detector is PDA and I am using multi channel detection with wavelengths of 210, 280, 320 nm. Why are my chromatograms and spectra so bad or what parameters do I need to optimize?

file:///var/folders/pb/d3ycr5z174377vzkvd55c1440000gn/T/com.apple.Safari/WebKitDropDestination-HHnHm43I/Skærmbillede%202018-12-24%20kl.%2015.48.08.png

bear in mind that i am not that familiar with LC-MS

Thanks in advance

Re: Optimizing applied LC-MS method

Posted: Mon Jan 07, 2019 8:17 am
by Rndirk
Hi,

First and foremost: if you are not familiar with LC-MS, you should get a training from whoever who employs you or let you do this project.

We can not see the picture you posted; see the sticky on how to post chromatograms/spectra.

We don't know what you're trying to analyze, how you are preparing the sample before injection, what type of instrument you are using,.... It's not possible to give any advice.