ON THE USE OF MIXING REACTORS IN FLOW-INJECTION ANALYSIS WITH THERMALLENS CALORIMETRIC DETECTION

In flow injection analysis with thermal lens calorimetric detection, m ixing of reagent streams of different composition before the detection cell produces a large background noise. The noise is due to the heter ogeneity of the mixture which produces refractive changes in the probe beam direction. Procedures to measure the homogeneity of the mixture of solutions are derived, and used to evaluate and improve the mixing efficiencies of packed bead reactors. Using well-designed reactors, th e mixing noise can be reduced below the noise levels due to other sour ces.