A TIME-BASED INJECTOR APPLIED TO THE FLOW-INJECTION SPECTROPHOTOMETRIC DETERMINATION OF BORON IN PLANT MATERIALS AND SOILS

A simple and flexible time-based injector is described for the introdu ction of almost any desirable volume of sample and reagents in flow sy stems. The feasibility of application is demonstrated by improving the azomethine-H spectrophotometric method for the precise and accurate d etermination of boron in soil and coffee plant tissues. On-line progra mmed functions include: sequential injections and zone trapping, with a significant reduction of sample and reagent consumption.