Page 1 of 1

why so many peaks in gradient run

Posted: Wed Jul 27, 2011 3:30 pm
by krishchrom
hi guys,

When ever i am using gradient program i always used to find lot of peaks.
not only at the sarting and ending of graient program.
EXAMPLE: I have a mixture of highly polar, medium polar and non polar compounds to separate

A:Buffer (KH2PO4)
B:ACN or methanol
Time %A %B
0 100 0

10 100 0

30 20 80

50 20 80

60 100 0

65 STOP

problem is these small gradient peaks interfering my non polar impurities at 0.1% Level
and some times not reproducible.

Do u think anyof these following reasons

1.instrument make
2.Gradient ramp
3.Solvent/Buffer grades
4.Premixing of organic to buffer.

PLEASE ADVISE
Regards
Krish

Re: why so many peaks in gradient run

Posted: Wed Jul 27, 2011 7:31 pm
by tom jupille
This is one of the more common questions that gets asked on the Forum. Watch this video for a discussion of what's going on and a diagnostic test to confirm the cause of the problem (you will have to register separately).
http://www.lcresources.com/more_resourc ... hp?f=3&t=5