Capabilities of fast protein liquid chromatography coupled to a double focusing inductively coupled plasma mass spectrometer for trace metal speciation in human serum

Abstract

The analytical potential of fast protein liquid chromatography (FPLC) coupled with a double focusing inductively coupled plasma mass spectrometer (DF-ICP-MS) was evaluated for the multielemental speciation of trace elements in human serum. The separation of the main serum proteins was performed in a MonoQ (HR5/5) anion exchange column using an ammonium acetate gradient (0-0.5 mol l ^–1 ) at the physiological pH of 7.4 (0.05 mol l ^–1 TRIS-HCl buffer) as the mobile phase. Proteins were first detected on-line spectrophotometrically at 295 nm and specific detection of metals was also carried out on-line by using a double focusing ICP-MS working at both low (m/Δm=300) and medium resolution (m/Δm=3000) in order to avoid possible polyatomic interferences. The use of variable resolution to carry out multielement speciation studies allowed the detection of Ca, Sr, Fe, Cu, Zn, Se, Mn, Cr, Pb, Al and Sn in different serum samples and introduces a new dimension to this area of investigation. From the multielemental study it was observed that detectable levels of Cr, Al, Pb and Sn were present in uraemic sera while those elements could not be detected in healthy subjects.