Sensitivity issues at higher concentrations.......urgent
Posted: Wed Mar 28, 2007 1:03 pm
Dear friends,
I am doing the LCMSMS analysis of two drug molecule (analyte & metabolite) in a single run. I am using API 2000, ESI source,MP of ACN : 0.1% Formic acid , chromolith C18 performance column, run time 2.5 min . The extraction process is by LLE by diethyl ether.
the problem I face is that the linearity is totally out since sensitivity of the analyle is reduced to almost 25% at higher CC conc CC7 CC8.,when compared to CC1 & CC2. whereas the metabolite is coming perfect.
One more information is that my machine was calibrated few days ago and earlier to that i had got the same method with good linearity.
Please send me your valuable suggestions at the earliest possibe....very urgent.
Shan
I am doing the LCMSMS analysis of two drug molecule (analyte & metabolite) in a single run. I am using API 2000, ESI source,MP of ACN : 0.1% Formic acid , chromolith C18 performance column, run time 2.5 min . The extraction process is by LLE by diethyl ether.
the problem I face is that the linearity is totally out since sensitivity of the analyle is reduced to almost 25% at higher CC conc CC7 CC8.,when compared to CC1 & CC2. whereas the metabolite is coming perfect.
One more information is that my machine was calibrated few days ago and earlier to that i had got the same method with good linearity.
Please send me your valuable suggestions at the earliest possibe....very urgent.
Shan