Abstract (EN):
In this work, a fully automated multicommutated flow system is described that allows the on-line dilution of highly concentrated rubidium solutions by employing the zone sampling approach and determination by flame atomic spectroscopy. The developed flow methodology exhibits great versatility, allows a wide range of dilution levels (dilution factors between 45 and 11,500), and results in broad working ranges. In addition, the dilution levels can be automatically adjusted to the sample concentration via computer control without the need of manifold reconfiguration. The proposed analytical system enables the automation of a well-established assay used to screen drugs with potential potassium-channel modulating activity (the so-called "rubidium efflux assay"), thus allowing high throughput screening required in drug development. System optimization and characterization was carried out using flame atomic emission spectroscopy. In addition, it was verified that the analytical features of the flow system, namely precision and accuracy, were maintained when working in the atomic absorption mode. The results were precise (RSD values lower than 2.6%) and accurate showing good agreement with those obtained using the manual procedure. The sampling frequency varied from 62-111 samples per hour depending on the dilution level required.
Language:
English
Type (Professor's evaluation):
Scientific
Contact:
aalmeida@ff.up.pt
No. of pages:
6