Page 185 - Applied Pharmacognosy
P. 185
Detectors in HPLC
Photodiode Array-Type UVD (PDAD)
❑ Rapid-scan spectrophotometric detectors are used for
monitoring of analytes at different wavelengths to obtain
absorption spectra of eluting components.
❑ A single scan covering the entire spectrum (190-800 nm) can
be done in less than 10 ms. Grating A single photodiode
measures absorbance for
Sample cell corresponding wavelength
at a resolution of 1 nm.
D2 / W lamp
Evaluation of peak purity
Peak identification Photodiode array 184
