Ultra-pure water TOC analyzer flexiTOC

for pure waterUV oxidation

Overview
The flexiTOC is a high-sensitivity Total Organic Carbon (TOC) analyzer designed for applications from tap water to ultrapure water. The analytical method is based on full UV oxidation of organic carbon compounds in aqueous samples to carbon dioxide (CO2) which is quantified using a selective NDIR detector. The system supports reagent-free operation for TOC levels below ~2000 ppb and can be operated with reagent (persulfate) for higher TOC concentrations or for samples with less oxidative substances.

Key capabilities

• High-sensitivity TOC analysis from groundwater/tap water to ultrapure/WFI water
• Full UV oxidation with optional reagent-assisted oxidation (persulfate)
• CO2 quantification by NDIR detector for selective, conductivity- and temperature-independent measurement
• Short analysis times and continuous self-cleaning reactor to avoid cross-contamination
• User-performable calibration and system suitability tests (SST) compliant with pharmacopeia requirements

Main technical specifications of the system

• Method & detection: full UV oxidation & NDIR CO2 detection (configurable with reagent)
• Sample volume flow: 20 mL loop (low range), 5 mL loop (high range)
• Total Organic Carbon (TOC) range: 2 to 5000 ppb (low range), 15 ppb to 20 ppm (high range)
• Related norms: USP <643>, EP 2.2.44, DIN EN 1484, DIN 32645, 21 CFR part 11 (software option), IP 45

Flowchart
The system scheme illustrates the principle of the flexiTOC UV oxidation and gas flow management; a heat exchanger and pressure regulator are required for higher sample temperatures/pressures as specified in the technical requirements.

Options & Features

• Multiline Mode: flexiTOC pro provides 4 different inlets and an upgrade to measure up to 3 loops sequentially with configurable interval durations
• Sample mode: configurable offline sample measurement sequence for separate samples
• Enhanced hardware performance: optimized UV reactor geometry and harmonized gas flow with continuous monitoring
• Check of sample flow: alarm if inlet flow = 0 (with pressure sensor)
• Data export: measurement data export to external storage in various formats; cloud storage via network connection available
• Heat exchanger & pressure regulator: heat exchanger required >50 °C; pressure transducer required if incoming medium pressure exceeds 0.5 bar
• System status: software provides detailed status overview (operating hours for sensors, pump, UV lamp)
• IP54 protection for screen and fan as standard
• Calibration & System Verification Options: reagent and water blank determination, multipoint calibration with internal standard dilution, SST function (low range)
• 21 CFR part 11 software option available for pharma applications

Technical Specifications (table)
Method & detection: UV oxidation (full) & NDIR (enhanced oxidation; configurable with reagent)
Sample volume: 20 mL loop (low range), 5 mL loop (high range)
Period of measurement: 6 to 15 min
Measurement range: 2 to 5000 ppb (low range), 15 ppb to 20 ppm (high range)
Detection accuracy: ~3 ppb or 2 % (whichever is greater)
Ports: 2 for samples | 1 for reagent (standard); 1 for sample, 3 for SST (low range)
Related norms: USP <643>, DIN 32645, EP 2.2.44, DIN EN 1484, 21 CFR part 11, IP 45
Ambient parameters: relative humidity 10 to 95 %, temperature 10 to 45 °C
Interface ports: analog (4 - 20 mA) according to Namur NE43
Dimensions, weight, power: 400 x 300 x 600 mm, 24 kg, 110 - 230 V, 50 Hz, 70 to 105 W

Medium Requirements (table)
Type of sample medium: from ground water to ultrapure water (not suitable for wastewater or solids)
Sample temperature: 10 to 50 °C
Inlet pressure: < 1.5 bar (if > 0.5 bar a pressure reducer is needed for some configurations)
Compressed gas: air, oxygen, nitrogen — free of carbon dioxide
Inlet pressure of gas: nitrogen 1 to 1.5 bar | oxygen 3.5 to 5 bar

Characteristics / technical specifications

• Method & detection: full UV oxidation with CO2 detection by NDIR
• Measuring times: 6–15 minutes (user configurable intervals; sample interval 5–10 min with possible interruptions up to 24 h)
• Sample volume: 5 mL (high range), 20 mL (low range)
• TOC measurement ranges: 2 ppb – 5000 ppb (low range); 15 ppb – 20 ppm (high range); up to 100 ppm in diluting mode
• Detection accuracy: < 500 ppb ± 5 ppb; > 500 ppb ± 1 % (non-diluting mode); typical ~3 ppb or 2 % whichever greater
• Ports and I/O: analog 4–20 mA (Namur NE43) and multiple sample/reagent/SST ports
• Standards compliance: USP, EP 2.2.44, DIN EN 1484, DIN 32645, 21 CFR part 11 (software option), IP 45
• Ambient operation: 10–45 °C, RH 10–95 %
• Carrier/utility gas: N2, O2 or compressed air free of CO2; gas pressure 1–4 bar; consumption approx. 12 L/h
• Mechanical & electrical: 400 x 300 x 600 mm; 24 kg; 110–230 V, 50 Hz; 70–105 W
• Protection: IP54 for screen and fan
• Consumables & maintenance: calibration solutions, pump tubing replacement at intervals, UV reactor replacement after lifetime, followed by calibration