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Adding random content to check formatting Reference Wavelengths
A reference is great for correcting for baseline changes but is not always needed, and when set incorrectly have detrimental effects. Here is a comparison of the same sample analysis with different collection parameters. Two sets of collection parameters were collected simultaneously: The first being a sample wavelength of 210nm with the reference turned off. The second used the same sample wavelength parameters but with the reference set to a typical 360nm with a band width of 100nm. We can see the reference-off chromatogram looks normal, while the chromatogram with a reference of 360nm shows many negative peaks.
The sample in question contains multiple compounds that absorb through the entire UV and into the visible. Here is the spectrum of one of the peaks with the reference highlighted.
When compounds elute that absorb in the reference range (310nm to 410nm) Chemstation offsets the absorbance at 210nm accordingly. This is obviously an extreme example, but demonstrates the need of the analyst to be on guard for cases where the impact of incorrect reference is less apparent.
Coming Soon
Until soon is now, the wayback machine will have to suffice (sorry it is really slow): Wayback Machine

