DEVELOPMENT OF A SPECTROPHOTOMETRIC DETERMINATION OF SIDEROPHORES USING FLOW-INJECTION ANALYSIS

A method has been developed for the spectrophotometric determination o f siderophores using flow-injection analysis (FIA) based on the reacti on of siderophores with the ternary complex Eriochrome Cyanine R-Fe(II I)-cetyltrimethylammonium bromide. 2,3-Dihydroxybenzoic acid, 2,3-dihy droxynaphthalene, and tolypocine were used as the model iron-binding l igands. The calibration curve for one of the siderophores (tolypocine) is linear in the concentration range 2.6 x 10(-6)-1.5 x 10(-4)M. The determination limit (10 sigma) for tolypocine was 2.6 x 10(-6)M. The a pplicability of the method was demonstrated on the determination of th e complexation ability of siderophores produced by some entomopathogen ic fungi. Samples can be analysed at a rate of 30 samples per hour.