I'm working in a pharmaceutical company were instrumental calibration tests on a regular basis are mandatory. My new Agilent 6890 GC has been validated by Agilent technician and my calibration methods are based on those methods. However, I'm not able to repeat the Chemical Performance Evaluation test which includes 5 injections of Agilent standard (hexan with 0.033% of C14, C15 and C16).
I would like to ask any of you who do regular calibrations on your GC (or experience high deviation in repeated injections) how you resolve RSD problems in such test. My first impression was that something was wrong with the inlet. I changed everything such as the liner, syringe and the septum. I've pressure tested the inlet and that seems to be ok. Agilent's limit for those 5 inj. are RSD <3% and in the setup test (validation) the technician got far less than 1%. I, on the other hand, am getting around 6% which I find unacceptable. I'm strictly following the Agilent's method and injection procedure, using their standard and the right column (retention gap).
If you have any ideas what might be wrong I would appreciate your suggestion. The GC can not be officially validated by my company's QC and in use till this problem has been fixed.
By Jim Gorum on Friday, February 15, 2002 - 01:42 pm:
Run a long series of injection, like overnight and see if you have a problem for the many injections or if the problem just occurs for the first few. That assumes you have an autosampler. If you are manually injecting, that probably holds the answer. One percent precision injection requires a lot of skill. The installer and salesperson would have the skill.
By Anonymous on Saturday, July 20, 2002 - 03:12 am:
What parameters should be considered for periodical calibration of GC?
By R. Plausinaitis on Tuesday, July 23, 2002 - 07:48 am:
Manual injection was mentioned above, but if you are using autosampler problem might be there (we had it- correct tension of belt which moves syringe plunger is important). There are some checks (described in manuals) which can be performed by service.
By Anonymous on Thursday, October 10, 2002 - 12:15 pm:
Do you use a special liner, the 6890 gc (EPC-control) need a special liner!!! ( FOCUS liner, qwartz wool in the middel)
By Anonymous on Thursday, October 10, 2002 - 12:54 pm:
I would check the gas flow with a flowmeter, the oven temperature with a thermocouple and some sort of standardized method for the PQ using a certain test mix and column.
By Anonymous on Tuesday, October 29, 2002 - 10:42 am:
I have a Master's in Organic chemistry with specialisation in drug chemistry where we prepared drug's like Ibuprfin etc, studied the chemical formula, synthesis and properties.
I worked for three month's as an GC analyst.I'am looking for a job now, could any suggest how and where to approach(lab's and industries).
By Anonymous on Wednesday, October 30, 2002 - 09:24 am:
Are there some related links for this topic on the WWW?
By N.V.V.S.S. RAMAN on Tuesday, May 11, 2004 - 02:51 am:
Is there any other method to calibrate GC?
I am using GC-17A, GC-2010, Agilent 6890 and PE autosystem GC. I would like to have common calibration procedure.
Is there any procedure for calculting Sensitivity of FId?
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