Chromatography Forum

Hi

Why people tempt to avoid low wavelength(190-210nm) for detection?

Hi

Why people tempt to avoid low wavelength(190-210nm) for detection?

Low wavelength UV responds to lots of different types of materials, so there can be less specificity at the low wavelengths. But if your matrix is clean around your retention time, feel free.

We inherited an assay from a company which used 210nm for a trace level component assay, as the gross absorbance was higher at 210nm. We changed it to 280nm because the matrix then did not interfere, so even though the gross absorbance at the higher wavelength was less, there was a net improvement in selectivity/specificity, and the assay was improved.

Thank you so much!

Most solvents , even water, have high absorbance values below 205 nm ( UV cut-off) , so dynamic range of the UV detectors decrease , and also the noise increase.