Abstract: In a process for titrating substances by adding increments of a titrant in time intervals, the course of the reaction is monitored in its approach toward the end point (EP), and the addition of titrant is controlled. At least one differential component is determined from the course of the reaction and used for controlling the addition of titrant. The process can be performed by an apparatus that includes a delivery unit for the titrant and suitable devices for performing the monitoring, differentiating and control functions.