Page 4 - 4_TOC special applications
P. 4
SCA-130-401
■ Sample preparation the extracellular substances produced by the
The 4 – 10 µm large micro-algae of the algae or released into the culture medium
Chlorella vulgaris species can be measured after the algae have died off. The TOC
directly after sampling from the reactor determined this way is the carbon content of
without any further sample preparation. The the investigated algae. To draw conclusions
difference method was used for the biomass on the dry mass yield, the percentage carbon
determination. The method is suitable for all content in the algae must be determined.
other single-cell algae that exhibit a stable
carbon content under different growth Several direct and indirect methods are
conditions. available. The most simple and, at the same
time, highly reliable method is to combust the
Using the difference method, the TC and TIC washed and dried algae in a solid-matter
were determined and the TOC was TOC analyzer. A second method is to filter
subsequently calculated from these values. the algae, dry them and then determine their
Calibration using the resulting dry mass of the mass. In combination with TOC and
algae makes it possible to draw conclusions photometry measurements, a correlation
on the dry biomass content in the sample between the TOC value and the algal dry
from the TOC. mass can be determined, which provides
information on the carbon content of the
■ Corrrelation algae. From the carbon mass fraction and the
The TOC correlation (algae biomass/TOC) TOC value, the dry mass of the algae solution
must be determined for each type of algae can be very accurately calculated.
specifically. It can also be calibrated against
the determined dry mass.
Dry mass – TOC Calibration
■ Recommended analyzer / Configuration
TOC-L CPH
ASI-L (40ml) with stirrer option and external
Sparge-Kit
First, the algae sample is measured and the
TOC is determined. Subsequently, the
sample is filtered through a 0.2 µm syringe
filter and measured again in the TOC
analyzer to be able to distinguish between the
TOC content originating from the algae and
the carbon content possibly originating from
