Chromatography Forum

Any ideas?...5973A...Autotune looks good. Replaced the multiplier, ion source, column, syringe...set RFPA... ran coil drift and that was fine...also log amp was okay. For drug analysis ion ratios are out of limits. Analyzing a calibrator and updating calibration then analyzing the same calibrator produces IRO.
Thanks very much.
BC

Sorry to hear of your troubles. You seem to have done all the right things to ID the problem. Shooting low or high concentrations that don't match the concentration of the reference you used to put in the libraray causes our ratios to be out of range. But I'm sure yhou've taken that into consideration.
When all else fails, call Bill Davis, one of Agilent's service engineers (for mid-Atlantic area). He can generally solve anything.
Good luck and if you resolve it, let us who also have Agilents know.
Pardes

Thanks very much for the information. I will call the person you suggested. Someone suggested an unknown area of the analyzer as being possibly charged, resulting in change of ion ratios with an inconsistent manner.
A few days ago I took the analyzer apart and cleaned the quad., contacts and solvent rinsed all supporting metal structures. Just for grins I replaced the ion source for the third time in about a week. Not the same source recleaned but three seperate sources have been used. Upon autotune I had some nice precursers to 69, 219, 502. I switched over from Negative polarity to Positive which took care of that. With a successful tune I analyzed my calibrator and ran three reps of the same calibrator afterward as samples. The result is still ion ratio out of limits. This instrument has run a "fast" analysis for quite some time. 76 psi on the inlet with a 10 meter 100 um x .100um dimension and coating. It was set up with a GC Racer to give it the extra boost. When the Racer heating element burned out. I converted to 220 v on the GC and didn't replace the Racer. I don't find this satisfactory in temperature ramping. As you know there are temperature limits as you increase from 50 C to 330 C on the oven depending on where you are in that range. The Racer gave a more linear ramp and at a higher rate. I spoke with Dr. MacDonald of GC Racer fame at Pittconn and described my problem with unsatisfactory GC oven ramp rates NOT using the racer. For some unknown reason I never mentioned the IRO issue and am not sure if it is related to the change in equipment. (Guess I didn't consider this until today but our lab director did suggest this days ago...) This is the only instrument we use fast analysis for these particular analytes. Codeine and Morphine. Other instruments run a more "traditional" oven ramp and have no problems with the same samples. [/img]

How very bizarre that the same calibrators when run as samples have out of range ion ratios!
Sounds like a challenge for Agilent.
We had our own challenge of filaments suddenly burning out every few days no matter what we did.
Agilent was mystified after chaning every board and trying everything. Finally they suggested using the CI filaments which they didn't think would solve the problem, but IT DID. They are scratching their heads.
Currently we have a 5973 and a 5975 Agilent and we recently added a Shimadzu which shows great promise.
Are you in a seized drug forensic lab as well? We'll have to compare notes.

Appears to be a method problem. What once worked, doesn't work now with the GC configuration. So this was changed to a more "normal" analysis than "fast". Different analytical column was installed. Less pressure used also...seemed to improve things greatly. Depending on who I ask in the lab, this analysis: never worked, worked but was bad, worked okay, was alright. IF...this GC setup worked okay previously and now doesn't then I'm not sure why the change to ion ratio out consistently.
Thanks for the help.

BCBC,

Just curious and don't have a flow calculator so what does it show for a flow rate at 75 PSI and 100 micron X 10 meter column, if you please?

Best regards.

Sorry for the late reply. I've been on Vacation.

0.8 ml/min. for a flow of 76 psi.

Sorry it has been so long to reply to Pardes.

Please email me: jazzyfazzypanther@gmail.com