Chromatography Forum

Hi Everyone,

I've an HPLC system (Agilent) which is attached to an ELSD detector (Polymer Labs). The ELSD detector is connected to the system and gives peak area measurements in mAu.

However, I need to run some validation tests on the ELSD and the pass specifications (as per manufacturer instruction manual) are given in mV.sec.

How can I convert from mAu to mV.sec and vice versa? I can't seem to find the conversion factor anywhere. I would really appreciate any help on this. Thanks a lot!

Cheers,
Taylor

This is a conversion from an "electrical signal" as volts to "spectral signal" as absorbance units AU. The software in your DAD does this operation in the Black Box; however, you may derive the 'conversion factor' empirically by plotting the voltage signal against the absorbance value and acquiring the slope value for one of your Standard solutions. Set the Y-axis to readout as millivolts, run the standard sample; then set the y-axix to readout as AU, then run the STD. Plot 'millivolts' against 'AU"--The value of the slope would be your empirically derived conversion factor.