Equivalent Carbon Number Index : An index based on the boiling point of a chemical normalized to the boiling point of n-alkanes or its retention time in a boiling point gas chromatographic column (GC)
Department of Health and Human Services (US federal public health agency), The Agency for Toxic Substances and Disease Registry (ATSDR), Glossary (Total Petroleum Hydrocarons), GA, USA 1999. http://www.atsdr.cdc.gov/toxprofiles/tp123-c9.pdf, (Globally Harmonized Sys of Class and Labl of Chem - Brit) {635}