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how to increase the response ......
Posted: Mon Sep 29, 2008 8:46 am
by parveenqa
dimensions of column i am usong: Betasil C18 column
Dim(mm): 250*4.6
particle size: 5 micron
Posted: Mon Sep 29, 2008 9:08 am
by WK
parveenqa,
You won't get much of an answer with little information.
How about HPLC parameters?
What analysis are you performing?
Sample preparation / standard concentrations etc.
What S/N are you getting?
WK
Re: how to increase the response ......
Posted: Mon Sep 29, 2008 12:38 pm
by JGK
dimensions of column i am usong: Betasil C18 column
Dim(mm): 250*4.6
particle size: 5 micron
without changing the method moving to a 2.1 mm diameter column and halving the flow rate will double your existing peak height.
Alternatively, are you using the best detector for the job or can you adjust the detector the give an improved response.
There are a multitude of possibilities but, without more information about your analysis, we can not be of much help
Posted: Mon Sep 29, 2008 1:08 pm
by Bryan Evans
Reducing particle size from 5um to 3um will increase sensitivity:
http://www.imtakt.com/TecInfo/TI058E.pdf
Posted: Mon Sep 29, 2008 2:53 pm
by danko
changing the method moving to a 2.1 mm diameter column and halving the flow rate will double your existing peak height.
Actually, if moving from 4.6 to 2.1 column diameter, the flow rate should be multiplied by 0.208.
In theory, the expected peak height increase will be 4.8 times, but in my experience increase between 3 and 4 times is a reasonable expectation.
Best Regards
Posted: Mon Sep 29, 2008 10:07 pm
by JA
Only because they were so close in the thread list when I looked, I suspect this topic is a direct continuation from;
http://www.sepsci.com/chromforum/viewto ... 9264#43389
Posted: Sat Dec 20, 2008 8:29 am
by parveenqa
thankyou for your informations