Investigating aluminium citrate speciation by high performance liquid chromatography.

The toxicity of aluminium (Al) is dependent on its chemical form or species. However, there are no current techniques available to separate small molecular weight toxic Al complexes. In the present study, HPLC separation was combined with atomic absorption spectroscopic detection of Al in an attempt to determine the potential for this analytical method to separate Al citrate from other Al species. A total of nine different HPLC stationary phase supports along with numerous mobile phases were examined. Promising results were obtained with the Cyclobond I and Cyclobond III columns containing the beta- and alpha-cyclodextrin stationary phases, respectively and the cyano column. Using a mobile phase of methanol:water (1:1; v/v) containing 0.1 M triethylamine (TEA) and glacial acetic acid (pH = 4.0), Al was reproducibly retained for approximately 9 minutes following the injection of Al citrate onto the Cyclobond III column. Injection of other simple Al complexes showed no demonstrable recovery of Al under these same conditions. However, the more stable Al desferrioxamine complex was retained, but with a retention time that was only 3-4.5 minutes. Unfortunately, the retention characteristics and recovery of Al were not reproducible or sufficient with either of the cyclobond columns for routine quantitation of Al citrate in biological samples. The cyano column did provide better recovery of Al citrate (up to 65%) than could be obtained with the cyclobond column (up to 58%). However, manipulation of the retention time for Al citrate on the cyano column was limited to a period of only 3-4.5 minutes. Under similar conditions, Al desferrioxamine could be retained for over 10 minutes on this same column.(ABSTRACT TRUNCATED AT 250 WORDS)