For this study the samples were collected from two coastal environments of western Greece, Prokopos Lagoon
and Keri Lake. A total number of 38 samples were analyzed for their TOC and TN content while two different
certified reference materials were used for the validation. All the samples were analyzed by using the Combustion-
Infrared and Combustion-Chemiluminescence method using a Shimadzu TOC analyzer (TOC-VCSH) coupled to a
chemiluminescence detector (TNM-1 TN unit) (APHA, 2005; DIN EN 15936 2009; ASTM, 2008), as well as the
wet oxidation method of Wakley and Black (1934).