Diode-Array Detection (DAD) or Photodiode-Array Detection (PDA) is an analytical technique that can be used to determine the purity of an analyte or related impurity peak eluting during an HPLC separation.

What is a diode array detector and what are its advantages?

A Photodiode Array Detector is a microprocessor controlled multi-channel detector that permits simultaneous access to spectral data for several wavelengths simultaneously. In comparison the conventional UV-Visible detector has only a single channel detector.

What type of source is used in the diode array detector?

The CCD array spectrometer operates in a similar way, except that a tungsten lamp serves as the light source and a 2048 pixel element linear CCD array serves as the detector. Light from the source passes through a sample solution and into a monochromator.