Page 32 - 5_TOC in daily practice

Sum Parameter – Total Organic Carbon

Manual injection of low sample volumes

No. SCA-130-517

The manual injection kit can be used to The highly sensitive NDIR detector also
perform TOC analysis in gases or liquids. permits injection of very small volumes such
Manual injection of liquids requires just small as 5 µL.
sample amounts. In general, the injection
quantity is 50 – 150 µL. As a result, multiple
injections only require sample volumes of
less than 0.5 mL.

Figure: Injection blocks for manual injection
(IC and TC).

■ Calibration
As an example, a TC calibration using the
In particular, the manual injection kit is manual injection kit is discussed here. The
needed for the measurement of highly measurement range of the calibration is
valuable samples, or in cases of very small between 2.5 mg/L and 20 mg/L C (calibration
sample amounts available. substance: potassium hydrogen phthalate).

To retrofit the TOC-L with the manual The injection volume was 5 µL and injection
injection kit, the injection slider is removed for each calibration point was carried out at
and replaced by an injector block. Changing least twice.
both injector blocks (TC port / IC port) takes
less than a minute.

Afterwards the sample can be injected
manually onto the catalyst or the IC port
using conventional GC injection syringes.

As detection limit and reproducibility, among
others, also depend on the injection volume,
injection volumes of > 100 µL are often used.

Figure: TC calibration using an injection volume of 5 µL
(r = 0,9996).