SPECIATION OF BASAL ALUMINUM IN HUMAN SERUM BY FAST PROTEIN LIQUID-CHROMATOGRAPHY WITH INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRIC DETECTION

The coupling of fast protein liquid chromatography (FPLC) with inducti vely coupled plasma mass spectrometry (ICP-MS) was evaluated as a tech nique for studying aluminium bound to proteins present in human serum. Separation of human serum proteins was achieved on a MonoQ (HR5/5) an ion-exchange column using an ammonium acetate gradient (0-0.25 mol l(- 1)) at the physiological pH of 7.4 (0.05 mol l(-1) TRIS-HCl buffer). A luminium contamination was avoided with an on-line Al-chelating scaven ger column. Proteins were detected spectrophotometrically at 295 nm an d the Al detection was carried out on-line using both quadrupole ICP-M S and double-focusing ICP-MS systems. At metal basal levels in serum t he latter detector proved to be adequate for this detection. Results o btained with the procedure developed confirmed clearly that transferri n is the only significant Al-binding protein in unspiked uraemic serum . In addition, a high-resolution ICP-MS instrument was applied success fully as an Al-specific detector allowing for the first time Al specia tion studies in unspiked normal serum. The technique can also be used for studying the protein binding of elements other than Al.