Synthesis, characterization and application of a new fluorescence reagent for the determination of aluminum in food...

A new sensitive fluorimetry method for the simple and rapid measurement of aluminum in some food samples, which used 3',6'-bis(diethylamino)-2-{[(1E)-(4-ethoxyphenyl) methylene] amino}spiro[isoindole-1,9'-xanthen]-3(2H)-one (DEMAX) for Al(III) chelation is described herein. The fluorescence intensity of the aluminum-DEMAX complex remains unaltered for over 24h at room temperature and is a linear function of the concentration of aluminum in the 0-1000mg/L range with a detection limit (LOD, defined as 3s/b) of 3.02µgL^-1 and quantification limit (LOQ, defined as 10Sb/m) of 30µgL^-1. The relative standard deviation (RSD) was 0.1% for a 1µgL^-1 aluminum level. The influences of the analytical parameters such as pH, waiting time of aluminum-DEMAX complex, amount of reagent, effect of temperature etc. were investigated. The developed method was successfully used for assaying aluminum in some food samples and dialysis solution, measured by the new home-made fluorimetric system. The results of analysis of the certified reference material (INCT-TL-1) are in good agreement with the certified value.