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Sum parameter – Total Organic Carbon
TOC-Determination according to
EP 2.2.44
SCA-130-204
Since the USP (United States ■ System suitability test
Pharmacopoeia) regulations for the For the system suitability test, a standard
determination of Aqua Purificata and Aqua ad sucrose solution with a carbon content of 0.5
injectabilia has been implemented into the mg/L is prepared. A control solution of 1,4-
European Pharmacopoeia (EP), TOC benzoquinone with the same carbon content
analysis has become increasingly established was subsequently prepared. The blank water
in quality control. Users who test the TOC (ultra-pure water) used for this purpose may
content in pharmaceutical water must not exceed a TOC content of 0.1 mg/L. For
regularly test their TOC system using a the system suitability test, all solutions
system suitability test according to the including the blank water are subsequently
method described in the EP 2.2.44 measured and the resulting signals are
guidelines. recorded.
Blank water: r w
Standard solution (sucrose): r s
Control solution (benzoquinone): r ss
The peak area of the blank water is
subtracted from the peak areas of both
standard solutions. The recovery of the
benzoquinone standard is then calculated
with respect to the sucrose standard.
r r
ss w 100
■ European Pharmacopeia Recovery in %: r s r w
The EP 2.2.44 guidelines do not prescribe
any particular oxidation technique for TOC Results between 85 - 115% are acceptable.
determination. The TOC systems, however, The ultrapure water sample corresponds to
must be able to differentiate between the guidelines when its response signal (r u)
inorganic and organic carbon. This can be does not exceed r s - r w.
carried out either via removal of the inorganic
carbon (NPOC method), or via a separate
determination (difference
method). The limit of detection for TOC
should be at least 0.05 mg /L. The
applicability of the method must be
determined via a system suitability test.
