Page 4 - Shimadzu TOC-V Series
P. 4

Shimadzu Wet Oxidation TOC Analyzers Aim for High
            Sensitivity with  Great Oxidation Performance



            Wet oxidation/NDIR method



            TOC-VWP                                                                                                                   Trace level TOC measurement in ultra-pure water.

            TOC-VWS
                                                                                                                                      Conditions
                                                                                                                                                                                                    High-accuracy measurement of TOC
                                                                                                                                               Analyzer                 TOC-VWS                          as low as 2µg/L (ppb)
                                                                                                                                               Principle        TOC measurement by IC removal
                                                                                                                                                                  (acidifying and sparging)
                                                                                                                                             Injection volume           20.4 mL
                                                                                                                                          Number of measurements          5

                                                                                                                                      Results
                                                                                                                                                  Number              Results (µg/L)
                                                                                                                                                 #1                      2.31
                                                                                                                                                 #2                      2.27
                                                                                                                                                 #3                      2.52
                                                                                                                                                 #4                      2.47
                                                                                                                                                 #5                      2.49
                                                                                                                                                mean                     2.41
                                                                                                                                                 SD                    0.114µg/L
                                                                                                                                                 CV                     4.73%


                                TOC-VWP                                            TOC-VWS

                                                                                                                                      Measurement flow line diagram
                                                                                                                                      TOC-Vwp
            Newly designed high-sensitivity NDIR achieves      Powerful oxidation through a combination of
            ultrahigh sensitivity measurements.                peroxosulfuric acid, UV illumination, and heating.

            Sensitivity and accuracy enhanced by minimizing    No need of purging of reagent bottle reduces
            the reagent blanks that hinder accurate analysis.  consumption of carrier gas.

                                                                                                                                                                                                 Dehumidifier/
                                                                                                                                                                                               gas pretreatment unit
                                                                                                                                                            Gas flow
            Measurement Principles                                                                                                                            rate   Carrier gas
                                                                                                                                            Carrier gas     controller
            TC Measurement                                     TOC Measurement                                                                inlet
            Phosphoric acid and the oxidant (persulfate) are added to the   Subtracting the IC concentration from the TC concentration                 Acid         Dilution water
                                                                                                                                                                                                               Data
            sample, which is heated under UV illumination to convert the TC   determines the TOC concentration.                                    Oxidant                                                   processor
                                                                                                                                                                                                                       RS-232C
            in the sample to carbon dioxide. This carbon dioxide flows with                                                                     Autosampler
                                                                                                                                                   ASI-V                                         Non-dispersive                Computer
            the carrier gas via the dehumidifier into the NDIR sample cell.                                                                                                                     infrared detector           (not included with
                                                                                                                                                                                                                              TOC system)
                                                                                                                                                                                                    (NDIR)
            The area of the carbon dioxide peak signal is measured and this                                                                                                    IC sparger
                                                                                                                                                                                               Oxidation reactor
            peak area is converted to TC concentration using a pre-prepared                                                                                      Drain                         (UV illumination, heating)
            calibration curve.
            IC Measurement                                     NPOC Measurement                                                          Sample
            The sample is acidified with phosphoric acid and sparged to   The sample is acidified with phosphoric acid and sparged to
            convert the IC in the sample to carbon dioxide. This carbon   eliminate the IC. The NPOC concentration is determined by
            dioxide is detected by the NDIR and the sample IC concentration   measuring the TC (=NPOC) of the sample after the IC is
            is measured in the same way as TC.                 eliminated, using the same method as for TC measurement.

                                                                                                                                                                                                                         TOC-V Series
      4                                                                                                                                                                                                                      Wet Oxidation TOC Analyzer  5
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