X-ray absorption edge fine structure of potassium ions in various environments: application to frog blood cells

Science  13 Apr 1979:
Vol. 204, Issue 4389, pp. 191-193
DOI: 10.1126/science.311948


The edge spectrum is a sensitive probe of local chemistry. Edge spectra of potassium in various chemical environments were measured, and each environment gives a unique edge spectrum. Hydrated potassium has a unique spectrum that is insensitive to counterions. Comparison of the spectra shows that the chemical state of potassium in cells differs appreciably from that in aqueous solutions.