Hi good day everyone.
I am using a Shimadzu GC-MS QP2010 SE.
I am having a problem with the results of peak area.
Recently, even though two duplicate samples have the same chromatogram, the area integrated by the software shows a 70% difference (using quantitative area integration).
Another example given here is during my calibration curve preparation for methyl oleate. Even though the sample with higher concentration (0.0201g) has a higher intensity peak and a larger area, the area is again smaller than the less concentrated sample (0.01005g). (using TIC peak area integration)
Tabulated areas and chromatograms can be found in the attached file.
Any advice on how to proceed with this?
Your suggestion is much appreciated! Thank you in advance.
Sorry to say this, but welcome to the dumpster fire that is Shimadzu software. I have the same machine, and have run into this exact problem. What I have done is taken to exporting just the areas, assuming that the integrations are consistent (I've had problems with that, too) and then doing the calculations in Excel.
Note that other systems have calculation issues, as well. The curve fitting in the older Agilent ChemStation series was at times iffy, but nothing like what I've run into on the Shimadzu.
Hi Mark. Thanks for the prompt response. I don't know whether I should be sad or glad to hear that I am not the only one having this issue.
If it's something that is intrinsically wrong with the software, does that mean we can't do anything? But just to redo the analysis?
I am not that clear by what you mean, when you export just the area (if the integrated area is wrong). As in we just use the wrong value?
Thank you very much for your sharing, Mark.
Chin Seng Liew
I think it better to use MS Excel to do the calculation, you need to make a standard Curve using MS excel (Peak area vs Concentration), then you can use the standard curve equation to calculate the Concentration of the unknown samples.
Hi Omar. Thanks for the reply.
Yes, I think you are referring to the calculation of concentration after obtaining the area right? That's what I normally do too.
But now, I am stuck at the step before the standard curve equation. The area calculated by GC-MS is a bit weird.
Thanks for your suggestion.
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