Kinetic catalytic analysis: Extended theory of continuous addition of catalyst to a reference solution for nonequal reference and sample initial signals

The theory of kinetic catalytic determinations by continuous addition of a catalyst to a reference solution is extended to the general case where the initial signals used for monitoring the reaction kinetics in the sample and reference solutions may or may not be the same. A generalized treatment for pseudo-first-order reactions is developed and discussed. Two intersection times which could be either positive or negative, real or imaginary, have to be considered. When real and positive, the intersection times are used as the input analytical variable. A suitable nonempirical algorithm to determine the concentration of the analyte without resorting to a calibration plot is derived, and its validity is evaluated by means of experimental as well as simulated determinations. Conditions have been chosen to cover a wider range. The effects of the relative values of the sample and reference initial signals as well as dilution of the reference solution on the determination error are discussed.