Total organic carbon analyzer TOC-VWP

laboratoryfor wet measurementfor environmental assessments

Overview
Wet oxidation total organic carbon (TOC) analyzer TOC-VWP featuring a high-sensitivity NDIR detector for ultrahigh-sensitivity CO2 detection and measurement of TC/IC/TOC/NPOC.

Measurement principle
TC measurement
Phosphoric acid and persulfate are added to the sample and heated under UV to oxidize total carbon (TC) to CO2. The CO2 is carried by the carrier gas through a dehumidifier into the NDIR sample cell. The CO2 peak area is measured and converted to TC concentration using a calibration curve.

IC measurement
The sample is acidified with phosphoric acid and sparged to convert inorganic carbon (IC) to CO2. The CO2 is detected by the NDIR and IC concentration is determined as for TC.

TOC measurement
TOC is determined by subtracting IC from TC (TOC = TC − IC).

NPOC measurement
IC is removed by acidification and sparging; the remaining TC (NPOC) is measured using the TC procedure to determine NPOC concentration.

PC-Control model
Operation, control and data acquisition are managed from a PC with advanced software. Wizards simplify measurement and calibration setup. Data are stored as files and can be exported to Excel or other applications. Security features include password protection and operator access restrictions.

Applications (selected documents)
Evaluation of TOC of Sulfuric Acid — 2024-02-06; Evaluating the Quantity of CO2 Absorbed in Concrete — 2022-05-16; Evaluating the Carbonation of Concrete — 2021-11-26.

Features

• Wet oxidation TOC analysis using persulfate and UV heating.
• High-sensitivity NDIR detector for ultralow-level CO2 detection.
• PC-based operation, control and data management with export to common formats.
• Wizards for simple measurement and calibration setup.
• Security: password input and operator access restrictions.

Technical specifications

• Detection: High-sensitivity Non-Dispersive Infrared (NDIR) detector.
• Oxidation method: Wet oxidation with persulfate and UV heating.
• Supported measurements: TC, IC, TOC (TC−IC), NPOC.
• Sample pretreatment: Phosphoric acid acidification and sparging for IC/NPOC procedures.
• CO2 transfer: Carrier gas flow through dehumidifier to NDIR sample cell.
• Control & software: PC-Control model with measurement wizards, file storage and export/import capability.
• Security: Password input and operator access restrictions.
• Output: CO2 peak area converted to concentration via calibration curve.