scope:

This document specifies a multi‑parameter method for the determination of total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in drinking water, raw water, ground water, surface water, sea water, saline water, process water, wastewater and industrial wastewater applications, after a chemical oxidation process. It is applicable to both dissolved and bound to suspended materials. The method allows for determination of TOC ≥ 1 mg/l, TN ≥ 1 mg/l and TP ≥ 1 mg/l. The lower and upper working ranges are restricted by instrument‑dependent conditions (for example sample volume, reaction chemistry amounts) and can be adjusted for a wider range. The analysis procedure is carried out instrumentally by a single oxidation process under standard temperature and pressure. Dissolved nitrogen gas is not included in the TN measurement in this method. Depending on the analysis conditions and when present in the sample, certain portion of elemental carbon, cyanide and cyanate can be included in the TOC result. NOTE - The method can be applied for the determination of total carbon (TC) and total inorganic carbon (TIC). Volatile or purgeable organic carbon (VOC, POC) can be determined separately by this method (see Annex A).