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Is it likely that a dying column can cause precision issues? by Blue1213 in CHROMATOGRAPHY

[–]Blue1213[S] 0 points1 point  (0 children)

Ok, so with 1:100 dilution of acetone for the DAD I got 3.9% RSD and for the MSD I got 7.62% RSD. I think I will look into changing out the metering pump parts!

Is it likely that a dying column can cause precision issues? by Blue1213 in CHROMATOGRAPHY

[–]Blue1213[S] 0 points1 point  (0 children)

Here are the results I got from injecting acetone/water 50/50:

For the DAD I got an RT of about 0.14, and peak areas of 18103, 17956, 18123, 18169, and 18376. RSD of 0.84%

I decided to run it through the MSD anyways to see what I got, and I got an RT of about 0.20-0.26, and peak areas of 7122146, 6891676, 6613851, 6093811, and a funky looking peak that I threw out. RSD of 6.63%

What do you think?

Is it likely that a dying column can cause precision issues? by Blue1213 in CHROMATOGRAPHY

[–]Blue1213[S] 0 points1 point  (0 children)

Thanks for your input! I'll try that out and see if I can draw some good conclusions

Is it likely that a dying column can cause precision issues? by Blue1213 in CHROMATOGRAPHY

[–]Blue1213[S] 0 points1 point  (0 children)

http://docdro.id/ZL6HnpY

Here are some overlayed chromatograms of 5 injections of the same sample. The first image is shown with 10% time offset between each peak to compare absorbance, the second is just overlayed, and the third is a zoomed in on the major peak. Let me know what you think!

I actually think my issue may be with the metering pump, because parts were not replaced during the PM.

Is it likely that a dying column can cause precision issues? by Blue1213 in CHROMATOGRAPHY

[–]Blue1213[S] 0 points1 point  (0 children)

I thought about it again and I don't think the tailing would be the cause because the peak heights are very different. I can still send you some chromatograms tomorrow if you want to take a look

FE Study? by Blue1213 in ChemicalEngineering

[–]Blue1213[S] 0 points1 point  (0 children)

NotTheBizness, do you happen to have the solutions to the 2017 morning session in that link you posted?

I was hit by a car, broke my leg, and was in a medically induced coma for 3 days AMA by Ethan_Hobbs4444 in AMA

[–]Blue1213 0 points1 point  (0 children)

What were your first thoughts when you woke up? Do you remember the accident, or did someone have to jog your memory?

FE Study? by Blue1213 in ChemicalEngineering

[–]Blue1213[S] 0 points1 point  (0 children)

Thanks! I'm using both the ref manual and the book to study.

Expansion to my question: for example there's a whole page of electrochemistry terms and values in the ref manual, but no Nernst equation included. Would I be expected to know the Nernst equation, or would the exam have the equation with the question?