LAR Process Analysers AG - QuickTOC®uv

The QuickTOC®uv of LAR Process Analysers AG is an on-line measuring system for the determination of total carbon (TC), total organic carbon (TOC) or dissolved organic carbon (DOC) according to USEPA Standard Method 5310C.

Utilizing the popular UV-Persulfate method the QuickTOC®uv of LAR Process Analysers AG provides highly accurate TOC measurement in the low ppb range down to 1 ppb for pure water, drinking water and surface water.

Due to new legal regulations and extensive controls against the increasing environmental pollution TOC analysers are used today in the municipal area for ground-, drinking-, surface- and waste water monitoring and in industries to control process water streams.

A typical application is the continuous monitoring of critical phases of industrial processes to ensure the safety of production processes and to guarantee the quality of the produced goods.

End users are mainly from the (petro-)chemical and pharmaceutical industries as well as food-, beverage and electronic industries. TOD/DOC measurement is commonly used there to detect contaminations in cleaned but also in untreated waste water.

The QuickTOC®uv was developed to perform exact TOC/DOC measurements with the approved UV-Persulfate method.

The measurement of Total Carbon in a water flow can be performed very easily with the TOC-Analyser from LAR AG: The untreated sample is mixed with the carrier gas (air) and the oxidation reagent (Sodium Persulfate) and then conveyed through the UV Reactor. The CO2 is measured in a NDIR-Detector (Non Dispersive Infrared Detector) and shown as TC content in ppm C or mg/l C.

For the TOC/DOC determination the so-called TOC direct method or more precisely the NPOC (Non Purgeable Organic Carbon)-method is used.

To measure the NPOC content the sample stream analysis is performed in a multi-step process. The sample flows continuously into the analyser. In the first step the sample is acified with sulfuric acid to reach a pH-value of < pH 2 and purged with gas to remove the inorganic carbon. During this stage the potentially existing purgeable carbon (POC) is also removed. From this point the sample consists only of nonpurgeable organic carbon (NPOC).

In the subsequent stage the inorganic carbon free sample is pumped into the reactor where it is exposed to the ultra-violet light. The UV radiation together with the concentrated persulfate, which is also pumped into the reactor, completely oxydises the organic carbon compounds (NPOC) into CO2.

Upon leaving the reactor, the CO2 gas stream passes through the gas liquid separation device before entering an enhanced non-dispersive infrared detector (NDIR), which measures the CO2 concentration.

An 'on board' computer will calculate the data from the NDIR detector into concentration in mg/l or ppm. The advanced gas and liquid calibration capabilities assure accurate results.

The QuickTOC®uv from LAR Process Analysers AG offers greatest flexibility.