ISO 21793:2020

This document specifies a multi-parameter method for the determination of total organic carbon (TOC), total nitrogen (TNb) and total phosphorus (TP) in drinking water, raw water, ground water, surface water, sea water, saline water, process water, domestic and industrial wastewater, after a chemical oxidation process. It is applicable to both dissolved and bound suspended materials.
The method allows for determination of TOC, TN and TP. The lower and upper working ranges for these parameters are dependent upon instrument conditions (for example sample volume, reaction chemistry amounts) and can be adjusted for a wider range. Typical measurement ranges are shown in Figures C.1 to C.3.
The analysis procedure is carried out instrumentally by a single oxidation process.
Dissolved nitrogen gas is not included in the TNb measurement in this method. When present in the sample, elemental carbon, cyanate and thiocyanate will be included in the TOC result.