10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 1 2015 (January - March) Cerberin (2-o-Acetyl neriifolin) is the principal cardiac glycoside present in seeds of lessThan i greaterThan Cerbera odollam lessThan /i greaterThan .The seeds of lessThan i greaterThan Cerbera odollam lessThan /i greaterThan are used as a poison for suicidal as well as homicidal purpose by people around the world. Its detection in body fluids is somewhat difficult .The present study aims to develop a simple Ultra Violet derivative spectroscopic method for the estimation of cerberin from rat plasma without previous chemical separation using fourth derivative of the zero-order absorption spectra and the integrated area of the peak (valley) ranging from wavelength 305.2 to 307.2 nm. PRASANTH SS AND RAJASEKARAN A Cerberin, derivative, rat blood plasma, UltraViolet spectroscopy 749-758