I am interested in detecting Ethyl Bicyclic Phosphate cas# 1005-93-2. The only double bond present is between Oxygen and Phosphorus. Is it detectable by UV?

In theroy, there may be electronic transitions between the non-bonded electrons on oxygen to a pi-star orbital, similar to what occurs in C=O, S=O and N=O systems. The wavelength may be anywhere from 215 - 300 nm, although the absorptivity is likely to be low for this functional group. I successfully detected a compound with structure R-P=O(OH)-R at 215 nm in phosphate buffer and acetonitrile.

In practice, a good way to find out would be to perform a wavelength scan on this material in your HPLC solvent in a UV/VIS scpectrometer. This would also give you an idea of the wavelength to use for detection.