Analytical Sciences

Abstract − Analytical Sciences, 19(12), 1611 (2003).

Identification of a Metallothionein in Synechococcus by Capillary Electrophoresis Hyphenated with Inductively Coupled Plasma Mass Spectrometry
André F. LAVORANTE,* Maria Fernanda GINÉ,*  Ana Paula G. GERVASIO,* Carlos E. S. MIRANDA,** Marli F. FIORE,* Cláudia M. BELLATO,* and Emanuel CARRILHO**
*Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP, Brazil
**Instituto de Química de São Carlos, Universidade de São Paulo, Av. Trabalhador Sãocarlense 400, 13560-970, São Carlos, SP, Brazil
A home-made system hyphenating capillary electrophoresis with an inductively coupled plasma mass spectrometer (CEICP-MS) for cadmium speciation of protein-binding and free cadmium ions in solution is presented. The CE-ICP-MS interface consisted of an acrylic block with an internal volume ca. 20 μL in which a platinum electrode, a capillary column, and a connection to an ICP nebulizer were inserted. A make-up electrolyte solution containing 50 mmol L-1 Tris-HCl buffer solution (pH 9.0) was continuously flowed through the interface to the ICP nebulizer. The separation of free Cd ions, Cd-cysteine, and Cd bounded to metallothionein (MT) isoforms from rabbit liver was carried out by capillary electrophoresis, and the analytes were detected by ICP-MS. The feasibility to isolate metallothionein compounds extracted from the cyanobacterium Synechococcus PCC7942 was demonstrated. The Cd binding proteins were induced in Synechococcus PCC7942 and further analyzed by CE ICP-MS.