Chromatography Forum

I need to use a detection wavelength of 774 nm. I plan to use a DAD. Can I or should I do some kind of wavelength accuracy. If so, how can this be accomplished?

use the "UV-Vis accuracy precision check kit", it's a commonly used system suitability check--and also estimates the stray light interference--the kits are actually quite good; they are easily available online by the typical search/find procedures.
I use it once per quarter year on our shimadzu uv-vis device.
bon chance!

Are you sure about 774 nm??? Or do you mean 774 THz? 774nm would be extraterrestical sun light.

774 nm sounds reasonable to me. My PDA has a range from 190-800 nm, which is typical. Are you playing with something like this:
http://www.licor.com/bio/products/reage ... sEster.jsp ?

Erbium perchlorate is what I've used in the past, though it only is typically used up to ~522 mn, I believe. Holmium oxide has a peak at 641-nm. I don't know of much that goes beyond that.

How critical is this?

How critical is this?

1. UV or visible absorbance spectra in solution usually do not have a great deal of fine structure.
2. the bandpass on HPLC detectors is usually fairly wide.
3. Even the USP and EP allow +/- 3 nm error in their default adjustment limits.
4. In any case, you are running your calibrators and samples on the same instrument so any error would apply equally to both.

Conclusion: unless the compound has a feature-rich spectrum, I usually don't worry about wavelength accuracy very much.