Determination of Agmatine Rate by Spectrofluorimetric Method in Alkaline Medium: Optimization and Application on Shrimp.

Abstract

In this work, a spectrofluorimetric method was developed to determine the rate of agmatine (AGM) in shrimp using orthophthalaldehyde (OPA) as derivatization agent. To optimize analytical results, the stoichiometry of the orthophthalaldehyde-agmatine complex (OPA-AGM) was determined. The effects of agitation and temperature on the fluorescence spectra of the complex in alkaline medium (pH 13) were then studied. We obtained in all media satisfactory analytical performances with very low detection limits (DL) ranging from 0.36 to 2.52 ng/mL and a quantification limit (QL) oF 1.62 to 8.40 ng/mL The relative standard deviations (RSD) obtained ranged from 0.08 to 1.5%, which shows the excellent replicability of measurements. In addition, recovery rates found in shrimp extract, between 96.3% and 103.4%, show the accuracy of measurements. Lastly, the interference effects on the determination of agmatine rate with biogenic amines and some metal ions likely to be present in shrimp were studied.