change retention time with Gas Saver Time

Hi, 

Are you running split or splitless inlet conditions?  What is your total inlet flow at the time of injection?   Have you tried to run the split vent trap diagnostic to see if you have some restriction in the line?

Hi Dear,
my mode is split and its flow 200ml/min.
total flow is 205 ml/min.
how i can run this diagnosis ?

Hi Abbey,

I look forward to knowing your diagnosis.

Greetings, and thank you for compiling all of this information!  

A few comments.  On the diagnostic tests, you don't need to open any connections for them to run.  The images on the instructions just describe the system control applied for that test.  The split vent test is actually testing the filter restriction in the housing between the Swagelok fitting circled and the vent on top of that metal housing, so we should reconnect everything and re-run that test to be sure there are no issues.  

Liner selection is good, and is my personal go-to liner for split methods.  

Quickly compiling the basics from your flow variation, I see the following

For the repeatability, 

The repeatability seems good for manual injections.  However, the RTs are significantly later than the flow rate runs, so I presume this is using the original method with the flow ramp on the column and Gas Saver enabled?  

Comparing both sets of data, the RT seems off for the 4mL/min run.  I would expect the 4mL/min RT to be longer than the 5mL/min.  Was there any flow programming or differences in injection for that first run?  

For repeability, the gas saver was off and the column flow was constant at 4ml/min.

Yes, I repeat split vent restriction test without open valve by myself and passed.

alfausett said:

Comparing both sets of data, the RT seems off for the 4mL/min run.  I would expect the 4mL/min RT to be longer than the 5mL/min.  Was there any flow programming or differences in injection for that first run?  

The three runs was exactly the same condition ( flow rate constant )

hi abbey,

kindly let me share with you my method parameters for the repeatability test and column flow changing.

for repeatability, 

for column flow 

4 ml/min 

5 ml/min

7 ml/min

this problem exhausts me, kindly guide me to remedy it as soon as possible. 

Hi AhmedIsmail,  

I understand this type of troubleshooting can be very frustrating, and we need these systems to be running to do our job.  Based on the method conditions above, everything looks pretty typical except the method for the 7mL/min run.  For that column flow and a 100:1 split, I would expect the total flow to be 710mL/min (700mL/min split flow, 7mL/min column flow, and 3mL/min septum purge).  The system is registering 778.29 mL/min, which could indicate an issue.   

At this point, I recommend you call in to your local call center and request an on site visit.  I think this situation warrants a person to work with you in real time, although I do appreciate all of the effort you have put in to helping me troubleshoot the issue.   The difference in retention times between the two different 4mL/min sets of data is concerning.  I am convinced that the drift is not related to the Gas Saver feature, as we had that feature disabled for the testing.  Please feel free to reference this thread in the dialog with your local engineer.  I think some measurements are needed to verify the system calculations match the readings.

If you don't have local contact info, click on the Agilent logo at the upper left of this page, which will take you to the main page.  On the upper right side of the main page, there will be a link to 'Contact Us'.  

If you would, please update this thread with the root cause of the issue, as I am curious and have not been able to replicate it yet on my machine.  

Take care and good luck!

Abbey

alfausett said:

If you would, please update this thread with the root cause of the issue, as I am curious and have not been able to replicate it yet on my machine.  

I will do sir and I'm grateful for your effort to find the remedy.

alfausett said:

If you would, please update this thread with the root cause of the issue, as I am curious and have not been able to replicate it yet on my machine.  

I will do sir and I'm grateful for your effort to find the remedy.