Precise, continuous TOC analysis to the low ppb range for ultra pure and clean water applications
The QuickTOC®loop of LAR Process Analysers AG is an on-line measuring system for the determination of total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC) and dissolved organic carbon (DOC) according to DIN EN 1484, ISO 8254 and EPA 415.1.
As industries become increasingly dependent on pure water, on-line TOC analysis has become the preferred (and often required) method to validate purity and protect against contaminants that threaten expensive systems, public safety and product quality. The QuickTOCloop® easily satisfies the most stringent TOC monitoring requirements wherever pure water is produced or consumed. Some examples include Water for Injection (WFI) in Biotech and Pharmaceutical, boiler condensate reclaim in the Power industry, RO and DI water for the Microelectronics industry, and Municipal Drinking Water Treatment.
Thermal combustion technology
The QuickTOC®loop has been engineered to work without the aid of expensive catalysts by using temperatures of more than 1200°C, well in excess of the current state of the art for online thermal catalytic oxidation which uses temperatures of only 680° to 1000°C. Operating at these temperatures enables the QuickTOC®loop to quickly, completely oxidize even difficult-to-combust compounds, regardless of their composition.
Fast and precise measuring results
The QuickTOC®loop operates in a continuous batch mode, producing results every three to five minutes. This guarantees the detection of even brief, transient peaks throughout the day.
Principle of Operation
The QuickTOC®loop is designed as a closed system to restrict environmental and other contaminants. This enables the QuickTOC®loop to achieve measurements in the low ppb range.
TOC is measured by injecting small amounts of sample into a stream of conditioned carrier gas that circulates continuously through a high-temperature furnace. The QuickTOC®loop then measures the resulting CO2.
The QuickTOC®loop conditions the needed carrier gas from the ambient atmosphere, so no gas cylinders are required. The loop injection system is connected to the carrier gas circuit by a system of valves which are closed to the carrier gas lines, but open for the introduction of sample.
The sample is drawn, rather than pushed, by a vacuum pump into the loop sample injection line. The possibility of contamination from the pump is thus eliminated by placing it downstream from the measured sample.
The volume of the loop is a known constant, eliminating the possibility of inaccuracies resulting from incorrect dosing, and four different loop volumes are available to accommodate a variety of industrial applications.
Injection of the sample occurs when the valves are switched and the loop becomes a part of the carrier gas circuit. The sample is carried into a high temperature furnace where, at 1200°C, high temperature combustion converts all carbon-based compounds to CO2. This enables the calculation of true TOC as TC - TIC. It is important to note that the closed system of the QuickTOC®loop avoids the loss of VOCs, thus assuring complete measurements with no missing data that would make the measurement appear too low.
The measurement of inorganic compounds is performed in an additional reaction vessel, where a continuous stream of acidified water is injected with the sample and the evolved CO2 is stripped by the carrier gas.