4- What are bandpass and stray light? Why can’t we typically use Absorbance measurements above 1.0?
· Determined by width of exit slit
· Bandpass/spectral bandwidth is the difference between the upper and lower cut off absorbance values. If it is 50 nm, values differing from each other by less than 50 nm could not be resolved, while a 10 nm bandpass could resolve these differences.
· Stray light: energy reaching the detector that is NOT of selected wavelength
o Because the effects of stray light are enhanced at high absorbance