Investigations on the Crystallization Tendency in Urine with AC-Impedance Measurements and Cyclic Voltammetry

Abstract

The electrophysical properties of the outer and inner phase limit layers of a system (molecule cluster, solvate envelopes, adsorbate layers, etc.) can primarily be held responsible for nucleation, crystal growth, and aggregation in solutions. Electric double layers are formed, which are only partly or indirectly accessible to measurement. In recent years a great number of investigations were carried out, dealing with stimulation (initiation) or retardation (inhibition) of crystallization by means of different components of urine during stone formation. However, all these methods clarify only partial aspects of crystallization and do not give a complete view of urine (Adelman and Goldman 1981; Adey and Lawrence 1984; Blank 1986; Hille 1984; Lipinski 1982; Pethig 1979; Robertson and Scurr 1986; Schanne et al. 1978; Schelter 1985; Scurr and Robertson 1986). Our investigations aim to find out whether it is possible to differentiate urine with a “high crystallization tendency” from urine with a “low crystallization tendency” by determining the complex impedance and using cyclic voltammetry.