Page 53 - Application Handbook - TOC
P. 53

Sum parameter – Total Organic Carbon




                                         TOC – Determination methods according
                                         to EN 1484
                    SCA-130-501


            The EN 1484 standard “Guidelines for  the           The following graph shows how the
            determination of total organic carbon (TOC)         parameters are linked:
            and dissolved organic carbon (DOC)” defines
            various terms and parameters.
                                                                                    TC

            ■ Definitions according to EN 1484
            TC:    Total carbon – the sum of organically                   TOC                    IC
            bound and inorganically bound carbon
            present in water, including elemental carbon.              NPOC          POC

            TIC:   Total inorganic carbon  – the sum  of
            carbon present in water, consisting of              ■ Determination methods
            elemental carbon, carbon monoxide, carbon           The TOC can be determined according to
            dioxide (also carbonates and hydrogen               three different methods:
            carbonates),     cyanide,    cyanate,    and
            thiocyanate. TOC instruments mainly detect
            CO 2, originating from  hydrogen carbonates
            and carbonates, just like TIC.

            TOC:  Total Organic Carbon – organically
            bound carbon present in water,  bonded to
            dissolved or suspended matter.  Cyanate,
            thiocyanate and elemental carbon are also
            determined.

            POC:  Purgeable Organic Carbon – the TOC            ■ Difference method
            content that is purgeable under the conditions      For the difference method, the parameters
            of this method.                                     TC and IC  are measured. The TOC is then
                                                                determined by way of calculation.
            NPOC: Non Purgeable Organic Carbon – the
            TOC content that is not purgeable under the         TC: The analysis of the total organic carbon
            conditions of this method.                          is carried out via oxidation (thermal or wet-
                                                                chemical) and subsequent determination of
                                                                the resulting carbon dioxide using NDIR
                                                                detection.

                                                                TIC: Through acidification of the sample
                                                                using a mineral acid at room temperature and
                                                                subsequent NDIR detection of the expelled
                                                                carbon dioxide the inorganic  carbon is
                                                                detected.
   48   49   50   51   52   53   54   55   56   57   58