Hello everyon! I am using an Agilent 7890 based refinery gas analyzer, and I found a strange phenomeno. If I analyse sample with lo concentration of oxygen (our CRM gas is 0,5 V/V%) the oxygen peak elutes in a double peak. I calculated the response factors, and the oxygen‘s response factor is two or three times higher than the nitrogen’s ( I assume that it should be nearly the same). I think that a part of the oxygen is trapped or lost during the analysis. Do you have any ideas what can be the problem?
Mirkó Páncsics, an Agilent 7890 is the make and model of a Gas Chromatography (GC) system. By itself, it is not a specific "gas analyzer". A GC is used with a column, detector and a proper method of analysis to provide data. Collectively, that makes up the GC Method. You did not provide any GC method information and the possible reasons, esp training, to see a peak doublet (if that is in fact what it is) number in the hundreds. If you could provide a chromatogram, with clear scales and the detailed analysis method, then it may be possible to provide some constructive suggestions.
- Note: REAL peak 'doublets' are often caused by things like: overloading the column, wrong temperature profile, damage to the column inlet and/or incorrect connection to the column, contamination, co-elution, injector conditions which are inappropriate for the sample etc. Try to create a multi-level calibration table with stds to measure the retention, response and linearity of your method. Confirm the GC and method used are appropriate for the application. If possible, please contact the professionally trained GC chromatographer at your facility to assist you with the method and interpret the observation.
William Letter thank you for the answer. I will provide some deatiled information about our method and system.