Eur. Phys. J. E (2004) 13: 133-140
https://doi.org/10.1140/epje/e2004-00050-3

A nonparametric approach to calculate critical micelle concentrations: the local polynomial regression method

¹ Group of Biophysics and Interfaces, Department of Applied Physics, Faculty of Physics, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
² Department of Mathematics,Faculty of Informatics, University of A Coruña, 15071, A Coruña, Spain

^* e-mail: fsarmi@usc.es

Abstract

The application of a statistical method, the local polynomial regression method, (LPRM), based on a nonparametric estimation of the regression function to determine the critical micelle concentration (cmc) is presented. The method is extremely flexible because it does not impose any parametric model on the subjacent structure of the data but rather allows the data to speak for themselves. Good concordance of cmc values with those obtained by other methods was found for systems in which the variation of a measured physical property with concentration showed an abrupt change. When this variation was slow, discrepancies between the values obtained by LPRM and others methods were found.