Effect of tracer concentration on homogeneity and carry-over

These 2 industrial trials, designed to identify whether tracer concentration has any effect on carry-over, compared the same product at two very different concentrations (200 and 1000 ppm) in order to determine the rate of carry-over for a given quantity of premix fed into the circuit. Two tracer batches and two collector batches were used at each concentration, and sampled at two sampling locations: at the mixer output and the elevator output.

These concentrations were chosen to span the conventional test concentration (250 ppm) and to correspond to a range of uses for drug molecules.