Analysis of Hemolymph Ecdysteroids in the Crayfish Procambarus clarkii by High Performance Capillary Electrophoresis

Abstract

Five ecdysteroids (ecdysone, 3-epiecdysone, 20-hydroxyecdysone, 3-epi-20-hydroxyecdysone, and 3-dehydroecdysone) were completely separated by micellar electrokinetic chromatography on a fused-silica capillary (50μm×50cm effective length) with 100mM borate buffer, pH 8.9, containing 100mM sodium dodecyl sulfate (SDS) and 15mM γ-cyclodextrin (CD). Addition of γ-CD to SDS micellar solution improved the resolution and allowed analysis within 10min. The limit of ultraviolet detection was below 50fmol, as determined by injected amounts of the authentic compounds. This method was applied to the analysis of ecdysteroids in the hemolymph of the crayfish Procambarus clarkii, in which physiological change was induced by eyestalk removal.