How does a PDA detector work?
Diode-Array Detectors A deuterium lamp is used, but it is the white light that is directed through the flow cell before it reaches the diffraction grating. The light then strikes the diffraction grating and is directed onto a linear array of photodiodes (thus the name of the detector).
How do you calibrate a PDA detector?
HPLC Calibration : UV-Vis / PDA detector by reference energy check. Calibration procedure: Flush the system with mobile phase either HPLC grade water or HPLC grade methanol. Check the reference energy for lamp in UV-Visible /PDA detector lamp at 225 nm.
How does a UV VIS detector work?
HPLC UV VIS detectors operate by passing visible and UV light through a sample in a flow cell, then measuring the absorption of the different wavelengths that pass through the cell. The amount of light absorbed provides information on the properties of the sample of interest.
What is the difference between Dad and PDA detector?
The HPLC/UV generally only measures a couple of user-selectable specific wavelengths simultaneously. The photo diode array (PDA), also known as the diode array detector (DAD) can measure the entire wavelength range in real time, which may provide other advantages.
Why caffeine is used for HPLC calibration?
If you mean the use of caffeine to check UV wavelength accuracy, lots of chromatographers prefer to use it over holmium oxide filters (or use it in addition to) because caffeine has both a local min & max in the UV range that’s at least close to the wavelengths commonly used on a daily basis.
What is a UV flow cell?
A UV flow cell introduces the sample to the detector. An ultraviolet detector is known as a or a UV/VIS detector. It is a nondestructive detector used for liquid chromatography. It measures the amount of ultraviolet or visible light that is absorbed by compounds of a mixture being eluded off the chromatography column.