title: Use of ultrafiltration and chromatography to assess aluminum speciation in serum after deferoxamine administration.
abstract: Deferoxamine effectively chelates aluminum by forming aluminoxamine, a low-molecular-weight compound removable by dialysis. However, aluminum-bound species other than aluminoxamine might be present in serum after the administration of deferoxamine. To study aluminum speciation after the administration of deferoxamine, high-performance liquid chromatography (HPLC) and ultrafiltration techniques were used. Samples of serum were obtained from six dialysis patients 44 hours after the administration of a single dose of deferoxamine. HPLC and ultrafiltration studies were performed. In the HPLC studies, samples underwent ultrafiltration, the filtrate was injected into the chromatographic system, and detection was performed by UV light and atomic absorption spectrometry. Unknown species of aluminum other than aluminoxamine were found in the early elution fractions. In the ultrafiltration studies, the same samples of serum from the six patients underwent ultrafiltration using membranes with different molecular-weight cutoff values from 1 to 30 kd. The percentages of aluminum found by ultrafiltration using membranes with cutoff values of 5, 10, and 30 kd were greater (64.4% +/- 2.5%, 63.5% +/- 3.7%, and 65.6% +/- 4.3%, respectively) than the percentages obtained with membranes with a 1-kd cutoff value (38.7%), suggesting that the unknown species of aluminum have a molecular weight between 1 and 5 kd. The unknown species of aluminum cannot be aluminoxamine because they behaved in a different way with HPLC.
authors.affiliation: Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, Hospital Central de Asturias, Universidad de Oviedo, Asturias, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Canteros-Picotto
authors.forename: J L
authors.initials: JL
authors.lastname: Fernández-Martín
authors.forename: J B
authors.initials: JB
authors.lastname: Cannata-Andía
mesh_terms: D000535:Aluminum / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification; D002614:Chelating Agents / Q000008:administration & dosage*; D015913:Chelation Therapy; D002851:Chromatography, High Pressure Liquid; D003676:Deferoxamine / Q000008:administration & dosage* / Q000097:blood*; D005290:Ferric Compounds / Q000097:blood; D006801:Humans; D009942:Organometallic Compounds / Q000097:blood*; D014462:Ultrafiltration
chemical_list: D002614:Chelating Agents; D005290:Ferric Compounds; D009942:Organometallic Compounds; C002577:ferrioxamine B; C049544:aluminoxamine; D000535:Aluminum; D003676:Deferoxamine