Automated development of a kinetic method for the continuous-flow determination of creatinine.

A "stopped-flow" method for the kinetic Jaffé determination of creatinine was developed, with the use of a computer-controlled continuous-flow system. Simplex optimization was used to find conditions of hydroxide and picrate giving maximum sensitivity for creatinine. We used a modified central composite experimental design to evaluate creatinine sensitivity and albumin, glucose, and acetone interferences as functions of hydroxide and picrate concentrations. More importantly, this work illustrates that the automated development of clinical chemical methods offers an efficient means of obtaining optimized, well-understood analytical procedures for subsequent routine use in the clinical chemistry laboratory.