Bandpass and Slit Width
Definition
The wavelength interval the monochromator delivers to the sample. Routine forensic UV-Vis runs at 1 nm or 2 nm bandpass; pharmacopoeial methods sometimes drop to 0.5 nm.
Related terms
- Absorbance (A)
- The base-10 logarithm of the ratio of incident to transmitted light intensity, A = log10(I0/I). Dimensionless. Linear with concentration in the working...
- Chromophore
- The molecular subunit responsible for a dye's colour, typically a conjugated double-bond system; chemical erasure destroys the chromophore while leaving the decolourised...
- Diode Array Detector (DAD)
- A UV-Vis detector that records the full 190 to 800 nm absorbance spectrum of every peak as it elutes, instead of a...
- Molar Absorptivity (ε)
- The proportionality constant in the Beer-Lambert law, in L mol⁻¹ cm⁻¹. A property of the analyte at a given wavelength, solvent and...
- Photomultiplier Tube (PMT)
- Cascaded electron-multiplication detector behind the monochromator slit on a dispersive scanning instrument. Reads one wavelength at a time at very high sensitivity.
Explained in
- UV-Vis Spectrophotometry and the Beer-Lambert LawThe wavelength interval the monochromator delivers to the sample. Routine forensic UV-Vis runs at 1 nm or 2 nm bandpass; pharmacopoeial methods sometimes drop...