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signal response

Posted: Wed Mar 29, 2006 4:24 pm
by mike
im getting a better signal response from my samples in SPLIT mode at 50:1 than I am in SPLITLESS mode.

why!

injecting the same amounts same temp profile and carrier flow rate.

Something to do with the flow!

Posted: Thu Mar 30, 2006 1:34 pm
by CE Instruments
Splitless only works if you refocus the peaks after the injection. Is your oven temperature below the solent boiling point ?
Also this should be in Gas Chromatography. :)

Posted: Sun Apr 02, 2006 4:51 pm
by KC
Sounds to me as though you will soon see peaks matching the retention time of your analyte in your blanks. Might this compound be collecting in your injection port. What is inj port temp, starting oven temp and detector type and temp.

Posted: Fri Apr 21, 2006 3:13 am
by Ron
Are you sure that the parameters are set properly for a splitless injection. I remember a similar problem several years ago when a co-worker was getting very poor sensitivity with splitless injection using the default instrument conditions, which included a purge on time setting of 0.0 minutes. After explaining that a purge on time of 0.0 meant the purge vent was on at time of injection, and setting a purge on time of .5 minutes sensitivity improved dramatically.