I measure pigments from bird egg shells with a spectrophotometer CM-2600d, should I work with 100%UV or 0%UV? What about pigments from bills and legs of birds?
The reason for the UV selection in spectrophotometers is for the evaluation of fluorescence (some materials absorb the UV and re-emit that energy at visible wavelengths). I am not sure if the materials you are interested in are fluorescent, but measuring with the UV included and excluded will give you that answer. If the results are the same, then there is no fluorescence present and it won’t matter which you select for future measurements. If the results differ, you will have to decide which is more relevant to your work. I would think that including the UV would make most sense since these materials are normally viewed in daylight, which has plenty of UV. But, again, it only matters if the materials are fluorescent … otherwise the results will be the same either way.
