Metodologia cinÃtica em fluxo nÃo interrompido: determinaÃÃo de dopamina em fÃrmacos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

A novel method to carry out kinetic analysis by Flow Injection, applied to dopamine determination in pharmaceuticals was developed. The method is based on measurements of the signal intensities at equivalent positions, around the peak, of the sample concentration gradient. The flow interruption was not necessary, requiring a low level of automation. The strategy of concentration gradient calibration was employed. A 24-factorial design was accomplished in order to plan the experimental condition of the flow methodology. Four system variables (factors) were studied and the effects were interpreted for six responses: sensitivity, linear regression coefficient, relative standard deviation of the results, magnitude of the concentration dynamic range, quantification limit and analysis time. In order to define the best condition, the six responses were considered, using the desirability function. While analyzing the dopamine samples, the matrix effect was noted. Then, the Method of Analyte Addition was implement by emploing of merging zones, followed of zone sampling. The ideal condition, defined by the desirability function was maintained. Four samples from three different companies were analyzed and a mean relative error of 3,3% was obtained. An estimative of standard deviation achieved with fifteen replicates was 0,0033 g.L-1. Moreover, an analytical throughput equal to 48 injections per hour was attained, higher than the standard method (by HPLC), around 3 injections per hour

ASSUNTO(S)

fÃrmaco quimica dopamina

ACESSO AO ARTIGO

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