Agilent GCMS Calibration Issues - Used for 8260B Analysis

[michellec-calab]

Hi all.

I'm hoping someone can offer some advice on a problem we are having with an Agilent 8890 GC/Agilent 5977 GC/MSD that we use for 8260B soils analysis. We are using this instrument with the Teledyne Tekmar Atomx Purge and Trap Autosampler. I'm still a relative novice to this so I will answer whatever questions you have to clarify as needed.

We are having to calibrate the instrument more and more often. It has gotten to where we are calibrating it nearly every time we run a batch of samples. It used to hold a calibration for ~ a week. The issues are with the early eluting compounds. They'll be passing for the curve, barely passing for the CCV/LCS and then, the next day, will fail the next CCV.

We are also having a continuous problem with getting the instrument to pass a BFB even after cleaning the source. We've tried re-tuning the instrument (including a manual tune) and that doesn't resolve the problem. We don't know if the 2 issues are connected.

Any advice would be appreciated and, again, I'll be happy to provide any additional information.

Thanks.

[LALman]

In my lab when running 8260 in scan mode, a calibration lasts for 6 months or more. Look for this publication....
"Agilent BFB Tuning for Environmental Analysis Three Ways to Succeed" Agilent document #5988-4373EN

Use the modified ATUNE method to tune you MS. Not sure if it applies to your newer instrument. Then run your CCV and see if 4-BFB passes the tune criteria. If it seems to pass well, only then put on a calibration curve following suggestions in SW846 Method 8260C or D. If the source is relatively clean and the filament is in good condition that calibration should last several months.

Also, very dirty soils run at too low a dilution can dirty up your source lenses and you might need a cleaning.