ECONOMIC-APPROACH TO ROBOTIC SAMPLE PRETREATMENT IN HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Economic automation of multistep analytical sample preparation is stil l a largely unsolved problem. Existing systems either handle only a fe w steps of a complex analytical scheme or they offer a complete soluti on at relatively high cost. This paper shows, using a rather general e xample that it is possible to construct a system in the analytical lab oratory with an optimal balance between automating most steps of the a nalysis scheme and still keeping the costs of the system within bounds . A practical example from pharmacokinetic analysis is presented; pret reatment of blood plasma samples for nifedipine determination by high- performance liquid chromatography. The automated method involves steps such as aliquoting, pH adjustment, liquid-liquid extraction and evapo ration to dryness. The system is built around a robotic arm from comme rcial equipment not designed originally for use with a robot. Analytic al results and costs are compared to the manual method.