Spectrofluorimetric determination of trace aluminum in diluted hemodialysis solutions

In this study, a spectrofluorimetric method has been developed for the determination of aluminum based on the formation of an aluminum complex with N,N'-disalicylidene-1,3-diamino-2-hydroxypropane (DSAHP). The most suitable pH, solvent medium, complex formation time, Schiff base concentration and temperature were determined. The excitation and emission wavelengths were 270 and 437 nm, respectively, in which the DSAHP-Al complex gave the maximum fluorescence intensity at pH 3.0 and 6.0 in 50% dioxan-50% water medium. Under these conditions, calibration curves were obtained in three different linear limits, and was found that aluminum could be detected within the concentration limit of 0-10.0 microM and the lowest detection limit being 0.27 ng ml(-1). The stoichiometry of the DSAHP-Al complex was also determined spectrofluorimetrically under optimal conditions and the molar ratio of DSAHP-Al was calculated as 2:1. Using the developed method, aluminum was detected in hemodialysis solutions, and the results obtained were similar and comparable with those obtained using the method described in the British Pharmacopoeia within 95% confidence limits. This method can be used successfully for the routine determination of aluminum because it is quick, requires less amount of reactives, is sensitive, reliable and reproducible.