VOLUMETRIC TRIANGLE-PROGRAMMED FLOW TITRATIONS BASED ON PRECISELY GENERATED CONCENTRATION GRADIENTS

Linear concentration gradients were generated by means of computer-controlled micropumps, to implement triangle-programmed flow titrations. Precise determinations could be Performed under defined conditions without calibration. The use of inverse flow-rate gradients enables volumetric titrations to be Performed in constantly flowing streams. The mixing of flow-rate gradients of the titration reagent and the sample solution, which are inverse to each other, opens up a way to titrate samples with concentrations varying over several orders of magnitude. The zone sampling out of precisely defined triangle concentration profiles and the injection into a continuously streaming sample or standard solution opens up a way to methods of flow-injection analysis (FIA) with improved reliability and on-line calibration. The titrations and the FIA procedures are controlled and analysed automatically by a personal computer. A compact and fully automated flow titrator was developed.