Spectrofluorimetric flow injection determination of glycerol & ethylene glycol with Alizarin Navy Blue

A simple and accurate procedure for indirect spectrofluorimetric determinat ion of glycerol and ethylene glycol in aqueous media was developed. Alizari n Navy Blue can be oxidized by potassium periodate to produce a fluorescent compound, that can be detected fluorimetrically (lambda(ex) = 370 nn, lamb da(em) = 516 mm) by a flow through method. Glycerol and ethylene glycol rea ct with periodate decreasing its concentration and thus the forming the bas is for an indirect determination of these compounds. The influence of acid concentration, reagent concentration and manifold variables were studied. F or glycerol and ethylene glycol linear calibration curves were obtained in the ranges of 4.8 x 10(-7) - 8.7 x 10(-5) M and 6.4 x 10(-7) - 8.7 x 10(-5) M, respectively. The limit of detection (defined as the concentration that gives a signal three times the standard. deviation of the background signa l) for glycerol and ethylene glycol was 3.2 x10(-7) M and 4.3 x 10(-7) M, r espectively. The proposed method was applied for determination of glycerol and ethylene glycol in synthetic and real samples. The results obtained wer e satisfactory.