Homocisteina : desenvolvimento de um novo metodo de analise utilizando o sistema DIMP/T&R-MIMS

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

This research work describes a new method for the identification and quantitative determination of homocysteine in plasm, an intermediate of the cystein synthesis, which is generated from methionine in the organism. This new method uses the Mass Spectrometry by Introduction via Membrane (MIMS). A membrane probe DIMP (Direct Introduction Membrane Probe) and the T&R-MIMS method (Trap and Release-Membrane Introduction Mass Spectrometry) were employed, which operates by sampling the target compounds through a given period of time by adsorption in a silicone membrane, followed by a fast desorption produced on heating the membrane. Homocysteine analysis was performed by its derivatization through an esterification reaction with ethyl chloroformiate in a mixture of pyridine, ethanol and water as the solvent. The experiments were performed in a Monoquadrupolar Mass Spectrometer, under a SIM (Selected Ions Monitoring) mode of operation. The m/z 234 ion, which corresponds to the homocysteine [M-H]+ fragment, was monitored. Linearity tests led to a correlation coefficient of 0.998. Five runs of a single experiment showed a deviation of 2.5%, indicating the employed method leads to very reproducible results. It was observed a 97.4% of recovering for the homocysteine, which demonstrates that the proposed method can be applied for its quantitative analysis

ASSUNTO(S)

metabolismo espectrometria de massa

ACESSO AO ARTIGO

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