Detection in HPLC
REFRACTIVE INDEX DETECTOR
The solvent has refractive index
the presence of analyte will change the refractive index
NON-SPECIFIC because it doesn't specify the species
UV ABSORPTION
Most compound have some absorption in the UV
- Use solvent with no absorption
Some detector is single wavelength ( 254nm)
NON-SPECIFIC because no spectral resolution
But spectra of analytes can be recorded (UV- visible spectroscopy) with very specific kind of spectrometer (diode array)
Notes to UV-visible spectroscopy