Chromatography Forum

PeterS
Exactley, Ihave MRM 530-171 and CE around 50
the peak appeare less than the past but I can't get LLOQ= 3.0pg/ml with area equal at least 5 times the blank , they have the same area.



ctroster
When I say that EE(ethinyl estradiol) have low sensitivity , I mean that using simple tuning without LC , using Infusion pump
I prepare the standard in mixture of (1:1)(0.002MAmmoniumAcetate:MEOH) and Infuse it , do scanning , amnual & automatic tuning in -Ve MRM , Ididn't get good intensity or the possible daughters

Okay good to know - and good luck!

I was browsing Canadian links for LC-MS and bumped into this:

http://www.canadianlcmsgroup.com/group_ ... rOrals.php

04:10pm-04:35pm – "Determination of Ethinyl Estradiol in Human Plasma by Dansyl Chloride Derivatization Followed by Automated On-Line SPE Combined with LC/MS/MS" - Presented by TBA (MicroConstants Inc., San Diego, CA, USA)

Just a coincidence, or is this related to your work?

Hello smkh,

Good to know it works now. Hope it is sensitive enough.
I also have the experience you need a higher concentration for optimization from a syringe than finaaly in LC-MS.3

Good luck, peter