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Sum parameter – Total Organic Carbon
TOC determination in phosphoric acid
No. SCA-130-309
Phosphoric acid is one of the most frequently because the phosphoric acid damages the
used inorganic acids in industrial applications. combustion tube and the catalyst.
It is applied as starting material for the Due to this, the wet chemical TOC method is
manufacture of phosphate-containing used to measure TOC in phosphoric acid.
fertilizers as well as for the production of
water-softening agents such as detergent ■ Wet-chemical UV oxidation at 80 °C
additives. The determination of the TOC content in
Phosphoric acid is also used in the food phosphoric acid is carried out via wet-
industry – as acidification agent and chemical UV oxidation using Shimadzu’s
preservative in beverages or as antioxidant in TOC-V WP.
meats and meat products.
Its core technology is the powerful oxidation
applying a combination of sodium persulfate
and UV oxidation at 80 °C. This ensures that
all dissolved carbon compounds are
Particularly for these types of applications, it
is important to apply acids that are pure and converted to CO 2.
free from foreign substances. Manufacturers
and processors of phosphoric acids are In the presence of persulfate ions and UV
illumination, OH-radicals are formed which
increasingly using the TOC (Total Organic
Carbon) sum parameter for quality control. have a strong oxidative effect and convert
organic compounds to carbon dioxide. A
This parameter is a measure of the carrier gas transports the carbon dioxide
contamination of phosphoric acids by organic formed to the NDIR detector where they are
components. detected.
The TOC method by using the catalytic
combustion is not suitable for the
determination of phosphoric acid,
