Page 182 - Applied Pharmacognosy
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Detectors in HPLC
Refractive Index Detector (RID)
❑ Parallel visible light passes through the cell with pure solvent
in both compartments and is directed to a photodiode array.
❑ When solute with a different refractive index enters the cell,
the beam is deflected and detection occurs.
❑ RID does not allow the eluent composition to be changed
during analysis, meaning it cannot be used for the gradient
elution method.
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