Investigation of metal binding by recombinant and native metallothioneins by capillary zone electrophoresis (CZE) coupled with inductively coupled plasma mass spectrometry (ICP-MS) via a self-aspirating total consumption micronebulizer

K. Polec , J. Szpunar (1) , O. Palacios , P. Gonzalez-Duarte , S. Atrian , Ryszard Lobinski (1)

1 LCABIE - Laboratoire de Chimie Analytique Bio-Inorganique et Environnement

An interface between capillary zone electrophoresis and inductively coupled plasma mass spectrometry (CZE-ICP-MS) based on a self-aspirating total consumption micronebulizer was evaluated for a study of metal complexation by metallothionein. The elimination of the nebulizer suction (and thus of the laminar flow) allowed a separation efficiency comparable with that reachable with on-capillary UV detection whereas the low (6 ?l min-1) nebulizer aspiration rate allowed the minimization of the post-capillary dilution effect, and thus maximization of the CZE-ICP-MS sensitivity. Operating conditions were optimized with the natural rabbit liver metallothionein preparations allowing detection limits of ca. 10 ng mL-1 (as MT-bound Cd) to be obtained within 10 min at quasi-baseline resolution. Recombinant (mouse liver MT-1-Zn7) and natural (rabbit liver MT-1-Cd7 and MT-2-Cd7) proteins were then titrated with Cd(II) and Cu(I), and Cu(I), respectively. A number of mixed metal complexes with different migration times were observed as a function of the Cu : Cd ratio in the system.

Domaines: Chimie analytique

K. Polec, J. Szpunar, O. Palacios, P. Gonzalez-Duarte, S. Atrian, et al.. Investigation of metal binding by recombinant and native metallothioneins by capillary zone electrophoresis (CZE) coupled with inductively coupled plasma mass spectrometry (ICP-MS) via a self-aspirating total consumption micronebulizer. Journal of Analytical Atomic Spectrometry, 2001, 16 (6), pp.567-574. ⟨10.1039/b100905m⟩. ⟨hal-00291419⟩