Page 12 - 3_Chemical industry

SCA-130-305

■ Kit for high salt samples 10
9
For the determination, a TOC-L CPH was
equipped with a kit for high salt loads. The kit 6
consists of a special catalyst tube, a special Signal[mV]
mixture of various catalyst beads and a 3
ceramics grid, which replaces the platinum 0
net. -1 0 5 10
Zeit[min]

Fig. Example peaks of 50% sodium hydroxide
solution

■ Recommended Analyzer / Configuration

When using the high-salt kit, sample TOC-L CPH
acidification is carried out with sulfuric acid, OCT-L (8-port samples)
which is used here to modify the sample High-Salt-Kit
matrix. Compared to NaCl with a melting B-Type-Scrubber
point of 801 °C, the melting point of NaSO 4 is
higher (881 °C) which extends the lifetime of
the combustion tube.

■ Results
The 5% sodium hydroxide can now be
measured using the NPOC method. The
duplicate determination of the sodium
hydroxide yielded the following results.

Sample NPOC RSD
[mg/l] [%]
Sodium hydroxide <10 (8,2) -
(50%)
Sodium hydroxide
(50%) <10 (8,3) -

The sodium hydroxide met the required purity
criteria of < 10 mg/L TOC.