A simple approach to compensate the suction caused by the electrospray ionization source in capillary electrophoresis-mass spectrometry systems

Autor(es)

do Lago, Claudimir Lucio ; Rajh Vidal, Denis Tadeu ; Mendonca Francisco, Kelliton Jose ; dos Santos, Vagner Bezerra

• Tipo de documento: Artigo Científico
• Fonte: ELECTROPHORESIS; v. 35, n. 16, p. 5-pg., 2014-08-01.

Resumo

ESI sources continuously consume the liquid at the tip of the capillary, which causes the dragging of the BGE. The laminar nature of this flow causes the broadening of the peaks and loss of separation efficiency. The usual solution for this problem is to compensate this phenomenon by reducing the pressure at the inlet vial by either leveling of this vial or pumping off the air that is over it. However, one must know the pressure to be applied in order to prevent under-or over-compensation. The procedure herein introduced allows the easy calculation of this pressure by obtaining two electropherograms at two different values of separation voltage. The migration times of the peaks allow the calculation of the apparent mobilities even in the presence of the laminar flow. Therefore, one can calculate the contributions from both electrophoresis and hydrodynamic flow, and finally the pressure associated with the undesirable flow. This pressure is then applied as a negative pressure at the inlet vial in the following experiments. Increase of up to 192% in the number of plates was obtained in a simple experiment. In addition, the bubble forming caused by the ESI suction during injection was prevented by turning off the nebulizer gas during the changes of inlet vials. (AU)

• Processo FAPESP: 13/14993-1 - Caracterização e quantificação de monoalquil carbonatos em meio aquoso empregando dispositivos microfluídicos acoplado a um espectrômetro de massas
• Beneficiário: Vagner Bezerra dos Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/06642-1 - Formação e propriedades de adutos de hidróxi-compostos orgânicos com carbonato em meio aquoso e condições biológicas
• Beneficiário: Claudimir Lucio Do Lago
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/02156-2 - Investigação do uso da eletroforese capilar com detecção condutométrica sem contato para a obtenção de parâmetros analíticos e físico-químicos para peroxicarbonato, perácidos e monoetil pirocarbonato.
• Beneficiário: Denis Tadeu Rajh Vidal
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado