Friday, 13 March 2009:
Precise continuous TOC analyses in low ppb ranges for pharmaceutical water
QuickTOC®purity of LAR Process Analysers AG is an on-line measuring system for the detection of total organic carbon (TOC) in pharmaceutical water particularly for "Highly Purified Water" (HPW) and "Water for Injection" (WFI), according to USP Chapter 643 and EP 2.2.44.
The TOC measuring system QuickTOC®purity was designed in cooperation with customers from the pharmaceutical industry in consideration of their special requirements. In addition to general requirements, the accuracy of the measuring results was especially focused upon. This can be guaranteed by using the patented LAR high-temperature method (1200°C).
With a brand new measuring method from LAR (patent pending), easy operation and calibration are also considered.
According to its special applications for "Highly Purified Water" (HPW) and "Water for Injection" (WFI) the QuickTOC®purity was optimised for measuring ranges of 500 ppb, however measuring ranges of up to 2000 ppb can also be realised.
Thermal Combustion Technology
The QuickTOC®purity was designed to work without maintenance intensive catalysts by using a temperature of more than 1200°C. Regular thermic-catalytic digestion methods only use temperatures of 680° to 1000°C. The operation with a higher temperature enables the QuickTOC®purity to rapidly oxidise tough substances and mixtures, regardless of their composition.
Fast and Precise Measuring Results
The QuickTOC®purity works in a BATCH-Mode and measures the respective T100 values every 3-5 minutes, thus guaranteeing the precise determination of short and transient peaks throughout the day.
With the Batch-Mode the analyser is particularly useful for measurements on different measuring points (Multi-channel operation).
The analytical part of the QuickTOC®purity is a closed system and is thereby protected from environmental influences and other contaminants. This enables the QuickTOC®purity to perform precise measurements in the low mg/l(ppb) range.
The TOC is measured by injecting small, defined sample volumes into the carrier gas stream that circulates continuously through a high-temperature furnace where the water vaporises and all carbon compounds are safely converted into CO2. An option exists for the QuickTOC®purity to purify ambient air into pure carrier gas so that no bottled air or instrument air is needed.
The injection system is connected with the carrier gas stream through a ventile system. Under normal conditions the sample is directed through the injection-loop by a suction pump to prevent the sample from any contamination during the process.
For the injection the carrier gas stream is shortly directed through the injection-loop which leads to the actual injection into the high temperature furnace. At more than 1200°C all organic carbon is converted to CO2.
Calibration and Qualification
With the unique calibration method of the QuickTOC®purity, for which LAR has filed a patent, it is now possible to easily check the system for correct functioning at any time. For this, a calibration gas is used during the calibration period. It is injected into the measuring system similar to the water sample.
Furthermore, it is very easy for the operator to conduct suitability tests with the QuickTOC®purity. The necessary standards can be provided by LAR if required.