eBook: TOC and Microbial Detection Monitoring - 7

Real-Time Compliance

organic carbon through differential conductivity where pre-oxidized conductivity is measured, representing the inorganic carbon
(IC) which is subtracted from Total Carbon (TC). By subtracting
the pre-oxidized value, METTLER TOLEDO systems differentiate
between the organic carbon and inorganic carbon. This method is
fully compliant with recommendations in USP <643> and E.P.
2.2.44 which state "The discrimination may be effected either by
measuring the inorganic carbon and subtracting it from the total
carbon, or by purging inorganic carbon from the sample before
oxidation."

rates and the 185nm is the more powerful oxidizer. METTLER
TOLEDO Thornton constantly monitors UV lamp performance in
their sensors in several ways:
* UV Lamp Failure Fault: Triggered when UV lamp control logic
expects the lamp to be lit yet power drawn by the lamp supply
is zero.
* UV Lamp Over-Time Error: Triggered when UV lamp life has
been exceeded
* Lamp Life Regulation Algorithm: Refines the TOC algorithm to
regulate a TOC measurement based on known lamp life characteristics, providing increased stability of the TOC measured
value over the 6-month operating life of the lamp.

Japanese Pharmacopeia Compliance
The Japanese Pharmacopeia (JP), unlike USP or EP, has adopted a
TOC Test method which is applicable to both off-line devices testing
incoming, potentially contaminated, source water and on-line devices that test water samples with a higher level of purity. JP's intent
was to provide a single test method suitable for TOC systems monitoring high levels of TOC as well as devices monitoring lower levels
of TOC. However, compliance with the JP TOC Test Method is not
required for all TOC systems used in JP systems.

Pharmacopeia Compliance
Most TOC sensors on the market today are compliant with guidelines set in global pharmacopeia such as USP, EP, ChP, and JP. USP
<643> is the test chapter in the United States Pharmacopoeia
(USP) that sets the standard for TOC measurements and the equipment used to monitor TOC. Most of the requirements of USP
<643> have been harmonized in the standards of other pharmacopeia to include the following:

JP16 General Information Chapter G8 Water, Quality Control of
Water for Pharmaceutical Use, section 4.5.2, "Monitoring of TOC
as the Indicator for Organic Impurities", clearly states that a TOC
instrument which meets the requirements of USP <643 > or EP
2.2.44 is also compliant with the Japanese Pharmacopeia:

* TOC Sensor must meet System Suitability Test (SST).
* TOC sensor must be calibrated according to manufacturer's
specifications
* TOC sensor must be able to discriminated between organic and
inorganic carbon

The JP specifies the Test for Total Organic Carbon 2.59
and normally, TOC measurement should be conducted
using an apparatus which meets the requirements described in the JP method. However, if a TOC apparatus
conforms to the apparatus suitability test requirements
described in "643 TOTAL ORGANIC CARBON" of the

* TOC Limit of detection must not be >50ppb
* TOC must not exceed 500ppb
All TOC sensors for regulated water systems on the market today
meet the above challenges. In particular, METTLER TOLEDO
Thornton TOC sensors discriminate between inorganic carbon and

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eBook: TOC and Microbial Detection Monitoring

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