Advertisement

New inlet, same method, poor phenol chromatography

Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.

3 posts Page 1 of 1

Code: Select all

I have just installed a JAS UNIS programmable PTV inlet.  I ran a hot splitless PAH/Phenol method that was identical to the one we have been running on the old agilent inlet and my phenols have gone nuts (some are splitting, all are tailing/smearing and some have disappeared altogether).

I suspect it is a liner issue as the column has been clipped and is fairly new, (although it was starting to lose phenol performance, it was not as bad as it is now) . I have tried multiple methods of cleaning the liners and tried different glass wool configurations to no avail.

Would you expect a method like this to be transferable between different inlets or are there some parameters (e.g. start temp) that are specific to the inlet?

A brief summary of the method;

6890/5973
inlet temp 280c constant
splitless with 50ml split purge after 1 min, 20ml/min gas saver after 5min
col flow 1.2 (constant pressure)
DB5.625 column with de-activated silica pre-column, quartz column connector
de-activated glass liner, tapered splitless end, de-activated glass wool in situ
oven start temp 60c (can't remember ramp - I will check tomorrow)
injection speed 'fast' (agilent default)
2ul injection
sample: 50% DCM extract/50%toluene PAHs/phenols at 2ng/ul 

Before this I  tried pulsed splitless, 1ul injection, and 90%DCM extract/10%toluene with no luck

any ideas?
----suffers separation anxiety----

Is it possible to do a split injection such as 50 to 1 with a 2ul injection?

haven't tried it yet.

Somehow I accidentally crested two identical posts so please see the other post
----suffers separation anxiety----
3 posts Page 1 of 1

Who is online

In total there are 6 users online :: 0 registered, 0 hidden and 6 guests (based on users active over the past 5 minutes)
Most users ever online was 4374 on Fri Oct 03, 2025 12:41 am

Users browsing this forum: No registered users and 6 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry