The effect of the addition of MgCl(2) and of taurine on the concentration and distribution of ions, present in physiological fluid, in epithelial (EL) and compact (CL) layers of the human amniotic membrane has been investigated using the Bordeaux nuclear microprobe. Particle induced X-ray emission and Rutherford backscattering spectrometry techniques had been used to provide quantitative measurements. In physiological medium (Hanks' solution), the monovalent ions (Na+, K+, Cl-) concentrations were identical in both layers. This data indicates that the compact layer acts as a buffer which fix minerals. Mg(2)+, Ca(2)+ and phosphorus levels were higher in EL than in CL. The addition of MgCl(2) in Hanks' solution induced a decrease of the monovalent ions concentration in both layers except Na+ level in EL which remained constant, an increase of the Mg(2)+ level in both layers while the Ca(2)+ and phosphorus remained constant. Addition of taurine in the Hanks' solution implicated several observations: taurine had no effect on the Na+, Mg(2)+, Ca(2)+ and phosphorus levels in EL and CL, but decreased the K+ and Cl- concentrations in both layers. The quantitative results may be related to electrophysiological observations on ionic exchanges through channels and paracellular pathways. The nuclear microanalysis processing may be of great interest to explain pregnancies complicated by poly or oligohydramnios.